Table of Content

10 December 2019, Volume 38 Issue 12

Previous Issue    Next Issue

Dynamics and spatial differentiation of biomass carbon sequestration of Pinus massoniana forests in the Three Gorges Reservoir Area under future climate change scenarios.

FENG Yuan, XIAO Wen-fa, HUANG Zhi-lin, ZHU Jian-hua, YAN Xu-xin

2019, 38(12):  3567-3576. 

Asbtract ( 388 )   PDF (2237KB) ( 516 )  

To understand how climate change would affect carbon sequestration rate in main types of forests in the Three Gorges Reservoir Area (TGRA) at different spatial and temporal scales, an ecological process model (3-PG) and exploratory spatial analysis were used to simulate biomass carbon sequestration rate and spatial autocorrelation ofPinus massoniana forests under three climate scenarios (BS, RCP4.5 and RCP8.5) from 2009 to 2050 based on forest resources planning and design survey datasets. Biomass carbon sequestration rate of P. massoniana forests showed a similar tendency under the three climate scenarios, which decreases dramatically from 4.59 Mg C·hm^-2·a^-1 in 2009 and then levels off in 2026 after changing from positive to negative. In 2050, carbon sequestration rates under BS, RCP4.5 and RCP8.5 scenarios would be -0.14, -0.15 and -0.15 Mg C·hm^-2·a^-1, respectively. Under a changing climate, carbon sequestration rate would increase by between 8.31% and 9.71% in the P. massoniana forests in the TGRA, and the carbon sequestration rate would increase with altitude. Although there were insignificant spatial autocorrelations of carbon sequestration rate at the global scale, we found a significant spatial autocorrelation at local scale. There was a “High-High” aggregation pattern in the central part (Kaizhou and Wanzhou districts) and the eastern part (Zigui County) of the TGRA, and a “Low-Low” pattern in the southern part (Fengdu County and Banan District) of the TGRA. Yubei, Wanzhou, Wushan, and Zigui were the hotspots, while Banan District and Fengjie County were cold spots. Management of P. massoniana forests in the TGRA should beimproved in the future based on spatial and temporal changes in carbon sequestration rate, with the aim to promote the sustainable development of forestry and guarantee regional ecological security.

Dynamic comprehensive evaluation and influencing factors of afforestation efficiency at province scale in China.

MEI Hao

2019, 38(12):  3577-3584. 

Asbtract ( 205 )   PDF (847KB) ( 182 )  

With constantly advancing construction of ecological civilization, afforestation, as an important means of land greening, is playing an increasingly important role. Afforestation efficiency exerts direct effect on the efficiency of ecological civilization construction. Based on the comprehensive verification data of national afforestation, vertical and horizontal deviation maximization method was used to calculate composite index of afforestation efficiency from 2004 to 2011 in 30 provinces of China. We further analyzed the factors influencing afforestation efficiency. The results showed that among the 30 provinces, afforestation efficiency was optimistic in nine provinces and poor in eight provinces. Geographically, efficiency in South, East and Central China was good, compared to inferior in the Northeast, North and Northwest parts. With respect to the current year qualification rate of afforestation, the greatest influencing factors were meteorological disasters, followed by site conditions. Both factors were objective factors. As for 3-year preservation of afforestation, the major influencing factors were meteorological disasters and artificial harmful interference, followed by management problems and site conditions. Effects of subjective influencing factors, including artificial harmful interference and management problems, were on the rise.

Spatial patterns of trees in a south subtropical Pinus yunnanensis var.tenuifoliaforest after selective logging of large sized trees.

LI Yuan-fa, HE Ji-an, YU Su-fang, LIAO Liang-ning, WANG Hong-xiang, YE Shao-ming

2019, 38(12):  3585-3592. 

Asbtract ( 265 )   PDF (2706KB) ( 165 )  

Selective logging is an important way for sustainable management in multi-age forests. It not only changes the composition and proportion of tree species, but also alters their spatial distribution and correlation. Little attention has been paid to the restoration of forest community structure after selective logging of big trees at a long-term scale. In this study, pair correlation function g(r) and mark correlation function k_mm(r) were used to analyze the spatial pattern of a pinefir secondary forest that was formed from a forest with large-sized trees (DBH≥20 cm) being intensely harvested 46 years ago, in Nanpan River basin, southwest China. The results showed that: (1) This community showed no obvious habitat heterogeneity and presented a random distribution on the whole; (2) The small-sized trees were clustered together at very small scales (r=0-1 m), while the aggregation degree of same species was relatively high; (3) The spatial distribution of the six dominant species (n≥30) tended to be random with the increases of scale. Among them, Pinus yunnanensisvar. tenuifolia, Quercus variabilis andKeteleeria davidiana showed a mild aggregation distribution at small and medium scales (r=0-8 m), Betula alnoides had a strong aggregative pattern, whileSpiraea thunbergii and Rhus chinensiswere clumped at most scales (r=0-20 m); (4) There was no-obvious interspecific exclusion or competition. Our results indicated that the large-sized trees logged forest had formed a relatively stable spatial structure after long-term restoration and that intraspecific competition has become the main force for community succession.

 

Effects of aridification on nitrogen and phosphorus cycles in a Pinus sylvestis var. mongolica sandfixation plantation.

XIE Yao, ZHAO Qiong, LI Yan-zhen, YU Zhan-yuan, LIN Gui-gang, ZENG De-hui

2019, 38(12):  3593-3600. 

Asbtract ( 277 )   PDF (660KB) ( 96 )  

A field experiment with three rainfall reduction levels (natural rainfall, 30% reduction in rainfall, and 50% reduction in rainfall) was conducted in a Pinus sylvestis var. mongolica sand-fixation plantation in Keerqin Sandy Lands to investigate the effects of aridification on the nitrogen (N) and phosphorus (P) cycles. The forest ecosystem was divided into three compartments (tree, soil and aboveground litter layer). The amount and rate of N and P absorption (from soil to tree), return (from tree to litter layer) and decomposition (from litter layer to soil) were measured and calculated. The results showed that, compared with natural rainfall, 30% reduction in rainfall significantly reduced the amount and rate of N return by 27.3% and 37.3%, and did not affect N absorption and decomposition and P cycling. The 50% reduction in rainfall significantly decreased the amount of N absorption, return and decomposition by 59.9%, 36.0% and 50.3%, P return amount by 38.1%, N return and decomposition rate by 39.9% and 32.7%, increased litter P content by 27.4%, and did not affect the amount of P absorption, N and P absorption rates. The decreases in the rates of N and P return and decomposition following rainfall reduction indicated that aridification would bring the risk of nutrient imbalance to pine forest.

Age structure of Caragana aurantiaca young populations in the Yili valley, Xinjiang.

HAN Da-yong, ZHAO Yu, JIANAER·Ahan, ZHANG Wei, YANG Yun-fei

2019, 38(12):  3601-3608. 

Asbtract ( 381 )   PDF (886KB) ( 105 )  

Caragana auruntiaca, a dwarf legume shrub, only distributes in the Tekes riparian zone of Yili Valley in China. There is limited information on the age structure of C. auruntiaca young populations. In this study, two plots, an enclosure plot (Jiefang Bridge) and a grazed plot (76 Tuan), were set up in the concentrated distribution area of C.auruntiaca along the Tekes River. Three types of habitats, i.e. riverbank, floodplain and terrace, were selected in each plot, and three quadrats (20 m×20 m) were set up within each habitat. The age of young populations were identified by bud scale scar. The age structure of C.auruntiaca young population under two management regimes was examined, and the effects of soil factors on the age structure of juvenile plants was analyzed. In the enclosure plot, there were no 1-3 year-old seedlings, and the number of juvenile plants was concentrated in 5-10 yearold, suggesting the population belonged to the declining age structure in all the three habitats. In grazed plot, young populations in terraces and riparian habitat had declining age structure, while those in floodplain and in general had increa-sing age structure. Seedlings (1-5 year-old) were closely related to soil available nitrogen content, while trees (6-11 year-old) were closely related to soil available phosphorus content. The shrub ramet population was the most in 1-5 year-old, accounting for 69.9%, which belonged to increasing age structure. In the future management of C. auruntiaca shrub ecosystem, it is feasible to use moderate grazing to increase soil available nitrogen content, reduce forb coverage between shrubs, facilitate seed germination and seedling growth of C. auruntiaca, and promote population regeneration.C. auruntiaca can compensate for the negative effects from the decline of seedling population through vegetative reproduction, and thus could maintain the dominance of population number and its status as a constructive species.

Population structure and dynamics of old Ginkgo biloba in Nantong, Jiangsu Province.

ZHU Wei, ZHANG Guang-fu, ZAN Zhen-yu

2019, 38(12):  3609-3616. 

Asbtract ( 249 )   PDF (715KB) ( 94 )  

Old ginkgoes with age ≥100 years are main components of large old trees in central Jiangsu, providing vital ecosystem services. It is significant to understand quantitative population characteristics of such old ginkgo trees by population inventory within a certain area. The static life table of old ginkgo population in Nantong of Jiangsu Province was compiled by applying age class structure represented by diameter at breast height (DBH) classes and smoothing technique. There were 282 individuals of old ginkgo trees, with the sex ratio of female to male being 1.37. Most of the old trees were distributed in the southwest of Nantong. The population of old ginkgo trees showed inverseJ size distribution, and its survival curve trended to the type of Deevey0Ⅱ. There was a fluctuation of life expectancy for the whole population. The life expectancy of the second age classes was relatively low. The mortality rate curve and disappearance rate curve in the lifespan had similar variation trend, with the peaks in the 2nd and 4th age classes. Due to long life span with severe fragmentation in the distribution of those old trees, it is suggested to improve their habitat quality and strengthen protection in concentrated areas of Nantong, especially for the individuals after the 5th age classes.

Incubation temperature modulates the effects of exogenous nitrogen addition on decomposition and nutrient release of Phyllostachys edulis fine roots.

LIU Ren, ZHANG Yu-fei, JIN Zhi-fang, MAO Rong, ZHANG Yang, LI Xiao-dong, CHEN Fu-sheng

2019, 38(12):  3617-3625. 

Asbtract ( 340 )   PDF (790KB) ( 173 )  

Fine root decomposition is an important component of carbon and nutrient cycles in moso bamboo (Phyllostachys edulis) forests. However, how exogenous nitrogen addition and temperature interact to affect bamboo fine root decomposition and nutrient dynamics is still unclear. In this study, a 360day microcosm incubation experiment was used to assess the effects of nitrogen addition (0 and 5 mg·N g^-1 root) and incubation temperature (18 and 28 ℃) on cumulative CO₂ production, mass loss, nutrients (N, P, Ca, Mg, Fe, Mn, and Cu) concentrations and remaining percentages, and enzyme activities during fine root decomposition. Our results showed that CO₂ production, mass loss, and enzyme activities at 28 ℃ were significantly higher than those at 18 ℃, whereas N, P concentrations and remaining percentages, and P/Mn exhibited the reverse trend. The effects of nitrogen addition on bamboo fine root decomposition and enzyme activities varied with incubation temperature. Nitrogen addition significantly decreased cumulative CO₂ production and mass loss, N/P, N/Mn, acid phosphatase (AP) and glycosidase enzymes (BG) activities at 28 ℃, but decreased Mn concentration and remaining percentage, N/Mn, BG and acetyl grape amine glycosidase (NAG) activities at 18 ℃. Nitrogen addition and incubation temperature significantly interacted to affect cumulative CO₂ production at 0-180 d and 0-360 d, mass loss, AP and BG activities. By the end of incubation, N concentration, N/Mn, and P/Mn in decomposing fine roots were negatively correlated with AP, BG and NAG activities, while Mn concentration was positively correlated with BG and NAG activities. These findings suggest that exogenous N addition and incubation temperature co-regulated fine root decomposition and nutrient releases via regulating enzyme activities. Our results would help accurately assess and predict ecosystem C and nutrient cycles in bamboo forests under the context of global change.

Distribution patterns and diversity of plant communities in fluctuating areas of Chongqing section of Yangtze River.

CHENG Li-deng, DENG Hong-ping, HE Song, GU Li, QU Huan-huan

2019, 38(12):  3626-3634. 

Asbtract ( 423 )   PDF (992KB) ( 96 )  

The Ward’s minimum variance method was used to classify plant community types through plot survey in the fluctuation area of Chongqing section of Yangtze River. We analyzed plant species diversity in the communities and the effects of nine environmental factors on community distribution patterns using Canonical Correspondence Analysis (CCA). The survey recorded a total of 419 vascular plant species from 286 genera and 103 families. Compositae and Gramineae were dominant families. The fluctuation area was divided into 18 community types, including two shrub communities and 16 grass communities. The occurrence frequency of Form. Cynodon dactylon+Paspalum thunbergii+Eclipta prostrata was the highest. Altitude was significantly negatively correlated with soil water content, soil organic matter content, available phosphorus content and substrate type, and positively correlated with diversity index. The interpretation of the spatial distribution of plant communities by the first axis of CCA was 8.91%, accounting for 41.21% of total interpretation, which better explained the relationship between community and habitat. The distribution of plant communities was affected by the combination of various environmental factors. Among all the environmental factors, altitude and soil water content played a leading role. Shannon diversity index, Pielou evenness and Gleason species richness in the falling zone increased with elevation, while Simpson dominance showed opposite trend. The dissimilarity index and Cody index increased with elevation. Those results suggested that plant community of the fluctuation area was at the primary stage of succession, and that the ecosystem was unstable. The distribution and diversity of plant communities in different elevations were different. Flooding was the main factor accounting for such difference. Our results can lay a theoretical foundation and practical basis for the monitoring, protection and ecological restoration of the fluctuation area of Chongqing section of Yangtze River.

Divergent response of plant diversity to nitrogen addition in enclosed and grazing grasslands.

LIU Si-yang, LI Xue-hua, LUO Yong-ming, XU Meng-yao, MA Xiao-tong

2019, 38(12):  3635-3641. 

Asbtract ( 368 )   PDF (671KB) ( 313 )  

We assessed the effects of utilization mode (grazing and exclosure) and short-termnitrogen addition (0, 5, 10, 20 g·m^-2) on species diversity and functional diversity in grazing grassland and enclosed grassland in Horqin sandy land. For enclosed grassland, the vegetation height, density, coverage and biomass increased and species richness and dominance decreased with increasing nitrogen additions. The increasing nitrogen additions significantly decreased the indices of root traits for enclosed grassland, but had no effects on functional diversity except Rao index in 20 g·m^-2 nitrogen addition treatment. Grazing had greater effects on vegetation status and diversity of grassland than nitrogen addition. CWM of specific root length significantly increased with the increasing nitrogen additions. The interaction of exclosure and low nitrogen additions could stimulate vegetation restoration and plant diversity. In contrast, higher nitrogen additions would reduce plant diversity and ecosystem stability. Biomass was negatively correlated with plant diversity indices. Vegetation and species diversity were more sensitive than plant traits and functional diversity to short-term exclosure and nitrogen addition. Plant root traits showed strong responses to management measures, which suggested that functional diversity should be further studied to clarify the long term effects of grassland management.

Influences of environmental factors on species distribution in forest community in Wengyuan Qingyunshan Nature Reserve, Guangdong.

CHEN Xiao-xi, YANG Xin-dong, ZENG Xian-xing, CHEN Liu-bao, XIE Chong-lin, HUANG Jiu-xiang, WU Jian-hui, LI Yi-de, XU Han

2019, 38(12):  3642-3650. 

Asbtract ( 361 )   PDF (632KB) ( 170 )  

Uncovering the relationship between species distribution and environmental factors is the basis and premise for in-depth understanding of forest communities. In this study, 14 permanent plots were set up in Qingyunshan Nature Reserve. We used twoway indicator species analysis (TWINSPAN), redundancy analysis (RDA), Monte Carlo test, and variation partitioning to analyze the relationship between plant species distribution and environmental factors. The results showed that: (1) According to the TWINSPAN, 14 plots were classified into five communities: Castanopsis fissa+Castanopsis carlesii, Pleioblastus amarus+Cryptocarya chingii, Rhododendron kwangtungense+Lithocarpus naiadarum, Schima superba+Rhododendron moulmainense, and Cunninghamia lanceolata+Phyllostachys eduliscommunities. (2) The results of RDA and Monte Carlo tests showed that elevation, soil total calcium content, soil water content, soil pH, soil cation exchange capacity and soil available phosphorus were the main environmental factors affecting species distribution. (3) Results from variation partitioning showed that these 10 tested factors could explain 85.2% variation of species distribution. Among those factors, topographical, soil factors and their interaction accounted for 16.2%, 62.3% and 6.7% of the variation, respectively. 14.8% of the variation were unexplained. This result indicated that species distribution was mainly affected by the environmental factors, and less affected by the interaction between organisms and random factors.

The effects of storage conditions and time on endogenous hormone contents and seed germination of Aconitum gymnandrum from different altitudes.

ZHAO Di, BU Hai-yan, WANG Su-yu, ZHANG Yan-ming, LIU Kun, QI Wei, XU Dang-hui, WANG Shun-xia

2019, 38(12):  3651-3659. 

Asbtract ( 340 )   PDF (708KB) ( 49 )  

Seed dormancy and germination are important for germplasm resource conservation, population regeneration, and community establishment. Endogenous hormones have been gained great attention for their effects on seed germination and dormancy. However, the general theory or hypothesis has not been formed, especially few information is available on their adaptability to environmental conditions. In this study, seeds of Aconitum gymnandrum, a common species from deteriorated alpine meadows along a altitude gradient on the eastern Qinghai-Tibet Plateau, were used to explore the dynamics of endogenous hormones contents (ZT, GA, IAA, ABA) in seeds at room temperature and low temperature storage and their influence on seed germination. The results showed that seeds of Aconitum gymnandrumhad deep dormancy (the highest percent germination during experiment was 37.33%), with lower temperature storage being beneficial to seed dormancy. The percent germination from higher altitude was significantly higher than those from lower altitude, which might be due to the higher germination-promoting endogenous hormone contents (ZT, GA) and lower ABA contents. Seed germination or dormancy release was not caused by the increase in the contents of germination-promoting endogenous hormones or the decrease in ABA contents. IAA had positive effects on seed germination of Aconitum gymnandrum.

Effects of half-reduced nitrogen fertilization combined with organic fertilizer on functional diversity of soil microbial communities in oat field.

LU Hua, ZHANG Mei-jun, FENG Mei-chen, WANG Chao, WANG Xiao-xue, YANG Wu-de

2019, 38(12):  3660-3666. 

Asbtract ( 431 )   PDF (629KB) ( 88 )  

We evaluated the carbon metabolism characteristics of soil microbial communities under half-reduced N fertilization combined with organic fertilizer in the oat field. The aim was to investigate the possibility of the replacement of partial N by organic fertilizer from the perspective of soil microbial functional diversity. There were five treatments in the experiment: no fertilizer CK, conventional nitrogen N1 (pure N 90 kg·hm^-2), nitrogen fertilizer halved N2 (pure N 45 kg·hm^-2), and nitrogen fertilizer halved combined with organic fertilizer N2O1 and N2O2 (O1 contains a total N of 90 kg·hm^-2 and O2 contains a total N of 45 kg·hm^-2). The Biolog-ECO method was used to evaluate the metabolism characteristics of soil microbial communities on carbohydrates, amino acids, amines, carboxylic acids, polymers, and others. The results showed that N fertilizer halved combined with organic fertilizer changed the metabolic preferences of soil microbial communities on carbohydrates, amino acids, carboxylic acids and polymers in the oat field. After N fertilizer halved, there was a significant increase of the utilization on the six types of carbon sources for soil microbial communities with the increasing organic fertilizer application. Principal component analysis showed that amino acids and amines were the main carbon sources which induced the metabolism characteristic differences of soil microbial community among different fertilization regimes. After N fertilizer halved, richness and evenness of soil microbial communities were increased with the increasing organic fertilizer application. After N fertilizer halved, when the amount of organic fertilizer equaling total N of 90 kg·hm^-2, oat yield was increased by the changes of soil microbial functional diversity. Therefore, N fertilizer reduction and organic fertilizer substitution was an effective measure to improve soil microbial functional diversity in oat fields.

Effects of Aspergillus aculeatus on the quality and yield of perennial ryegrass.

ZHANG Ting, ZHAO Chun-cheng, FU Jin-min, LIU Lin-de, LI Xiao-ning

2019, 38(12):  3667-3672. 

Asbtract ( 231 )   PDF (519KB) ( 206 )  

Perennial ryegrass (Lolium perenne), a fine forage grass, is widely used in animal husbandry. Previous studies reported that application of fungi Aspergillus aculeatus could improve stress resistance and growth of perennial ryegrass. In this study, we investigated the effects of A. aculeatus application on perennial ryegrass growth, yield, hay yield, forage quality, mineral element content, growth phytohormones and metabolites under field conditions. Exogenous A. aculeatusapplication significantly increased the biomass, yield, hay yield of perennial ryegrass as well as the contents of N, P, K, Ca and Mn in leaves. Furthermore, leaves of perennial ryegrass treated with A. aculeatus had higher concentrations of crude protein and crude fat. Application of A. aculeatus had significant effects on growth phytohormones as well as metabolites of perennial ryegrass. These results provide a theoretical basis for further application of A. aculeatus on perennial ryegrass.

Carbon balance of summer soybean cropland under different irrigation and nitrogen fertilizer regimes.

LI Ling, LI Ya-jie, ZHANG Yong-jie, FU Xiao-wen, DU Xiao-jing, XU Wen-xiu

2019, 38(12):  3673-3679. 

Asbtract ( 232 )   PDF (503KB) ( 134 )  

To seek a better management measure of irrigation and nitrogen application for carbon emission reduction in summer soybean cropland in Yili River valley of northern Xinjiang, a field experiment with two-factor split plot design was conducted in Yining County in 2013. There were four levels of irrigation (3000, 3600, 4200, 4800 m³·hm^-2, designated as W1-W4) and three levels of nitrogen application (0, 150, 300 kg·hm^-2, designated as N0, N1 and N3). We examined the impacts of different irrigation and nitrogen fertilizer managements on carbon fixation, carbon emissions during production, soil respiration, net carbon absorption of cropland ecosystem. The results showed that under the irrigation levels of W2, W3 and W4, the changing curve of the total carbon fixation in soybean field emerged a climbing tendency firstly and then decreased with the increasing nitrogen application rates. The total carbon fixation of W3N1 treatment was 13902.53 kg CO²·hm^-2, being 16.4% and 6.5% higher than W1N0 and W4N2, respectively. Irrigation electricity, as the main source for carbon emission in agricultural inputs, accounted for 58.0%-77.1% of the total carbon emissions of production materials. Following that of irrigation electricity, chemical fertilizer accounted for 6.0%-21.6% of the total emission. The more production materials were inputted, the higher amount of total carbon emission was detected. The value of net carbon absorption of each treatment was positive, indicating carbon fixation in the soybean cropland ecosystem. W3 irrigation had the highest net carbon absorption. Under the condition of irrigation amount of 4200 m³·hm^-2 and nitrogen application amount of 150 kg·hm^-2, high soybean yield and carbon fixation were obtained, with net carbon absorption being enhanced.  

Isolation and plant growthpromoting ability of endophytic bacteria in Atractylodes macrocephalaKoidz.

YANG Hu-rong, CHEN Piao-xue, DAI Chuan-chao

2019, 38(12):  3680-3688. 

Asbtract ( 282 )   PDF (1110KB) ( 359 )  

To screen endophytic bacteria that promote the accumulation of bioactive ingredients in medicinal plants, endophytic bacteria residing Atractylodes macrocephala were cultured by pure cultured method and identified by 16S rDNA sequencing. The biochemical characteristics and effects on host plant growth were analyzed. Results showed that a total of 49 endophytic bacteria were isolated from A. macrocephala, including 11 genera. Bacillus and Pseudomonas were the dominant genera. Among the isolated strains, there were 10, 25, 19 strains with ability of nitrogen fixation, phosphorus solubilization and potassium dissolving, respectively. 35 strains were able to synthesize indole acetic acid. Bacillus endophyticus AMR83, a stain with all the above biological characteristics, can promote plant root growth, increase the volatile oil content inA. macrocephala roots by 100.55%, and adjust the proportion of active ingredients. The results suggested that AMR83 could be used as an endophyte to improve the yield of volatile oil and the quality of crude drug.

Effects of organic material application on soil arthropods in wheat-maize rotation system in North China.

WU Xian, ZHANG Ting, KONG Yun, LI Gang, ZHAO Jian-ning, YANG Dian-lin, ZHANG Gui-long, WANG Li-li, XIU Wei-ming

2019, 38(12):  3689-3696. 

Asbtract ( 288 )   PDF (494KB) ( 93 )  

To examine the effects of the combined application of organic materials and chemical fertilizer on the community structure of soil meso and micro-arthropods in wheatmaize rotation system in North China, five different fertilization treatments were carried out in Ninghe District, Tianjin. The treatments included chemical fertilizer application (A1), bio-organic fertilizer application (A2), combined application of chemical and bio-organic fertilizer (A3), chemical fertilizer application with straw returning (A4), combined application of chemical and bio-organic fertilizer with straw returning (A5). The results showed that a total of 1237 soil meso and micro-arthropods were recorded, belonging to four classes, seven orders and 36 families. Acariformes and Collembola were dominant groups in all treatments. Perlohmanniidae and Isotomidae were the dominant families in wheat season, while Perlohmanniidae and Mochlozetidae were the dominant families in maize season. Total individual number and diversity index (H) of arthropods in A5 treatment were significantly higher than that in other treatments in wheat season (P<0.05). The total individual number of soil meso and micro-arthropods varied across the treatments with an order of A5=A4>A2>A3>A1. Diversity index, evenness index and richness index of A4 treatment were significantly different from that of A1 treatment in maize season (P<0.05). The results of community similarity analysis showed that community composition heterogeneity of soil animals was high and the similarity coefficient was low in different fertilization treatments. These results indicated that fertilization regimes significantly affected the composition and structure of soil arthropod community. Bio-organic fertilizer application and straw returning significantly affected the abundance, diversity index and richness index of soil animals. The combined application of chemical and bio-organic fertilizer with straw returning was more conducive to the stability of soil animal community structure.

Ant species diversity in northeastern Yunnan.

HUANG Zhao, XU Zheng-hui, LIU Xia, LI Li-mei, WANG Ya-li, SHI Sheng-hui, SHI Yun, CHEN Zhi-feng

2019, 38(12):  3697-3705. 

Asbtract ( 393 )   PDF (518KB) ( 109 )  

We surveyed ant species diversity of the northeast Yunnan with plot method. The results show that there are 120 species, 41 genera, and 6 subfamilies of Formicidae in the study area. Pheidole watsoni Forel and Paraparatrechina sakurae Ito are the dominant species. There were 6 common species, 14 relatively common species, 33 relatively rare species, and 65 rare species. The order of ant species richness on the five vertical zones is: north slope of Daxuecao (70 species) > west slope of Yaoshan (50 species) > north slope of Zhenxiong (47 species) > south slope of Daxuecao (39 species) > north slope of Xiaocaoba (36 species). Ant species richness, individual density, and diversity indices were generally decreasing with increasing altitude, suggesting that altitude and air temperature were the key factors driving species diversity of ant communities. The main indices of ant communities showed multi-domain effect, as they were affected by climatic factors and human disturbance, with a more important role of the latter one. Although the five vertical zones have been disturbed by human beings in varying degrees, large areas of natural forests are retained in the Wumengshan Nature Reserve with Daxuecao as the core zone and Yaoshan Nature Reserve with Mount Yaoshan as the core zone. Due to the fogy and humid climatic characteristics in the study area, ant fauna and diversity are at the average level of that in Yunnan Province. Ant communities vary vertically, with different ecological functions and conservation values.

Effects of freezing-thawing cycle and long-term placement on PAHs desorption behavior in soil of Southwest China karst area.

AN Xian-jin1,2, LI Wei

2019, 38(12):  3706-3716. 

Asbtract ( 274 )   PDF (998KB) ( 99 )  

Soil is the main sink of hydrophobic organic pollutants (PAHs). Desorption and bioavailability of PAHs are mainly affected by the interaction strength between PAHs and soil, as well as their physical and chemical properties. The effects of natural freezing-thawing cycle and long-term placement on desorption of PAHs in soil of Southwest China karst area are still unclear. In this study, we examined the effects of two environment processes of freezing-thawing cycle and long-time placement on the desorption behavior of PAHs (phenanthrene and pyrene) in two typical soils (yellow soil and limestone soil) in Southwest China karst area. The results showed that the freezingthawing cycle and long-term placement significantly affected the desorption behavior of PAHs in soil, probably because due to the changes of soil particle structure and pores. Such changes may alter the interaction mode and intensity between soil particles and pollutants, change the isolation of adsorbed PAHs molecules from aqueous solution, and lead to the decrease of desorption ability and even being locked. Under the freezing-thawing cycle and long-term placement, the desorption rate of PAHs in Southwest China karst soil had a negative correlation with its hydrophobicity.

The variation of soil organic carbon and its influencing factors between reclaimed woodland and grassland in coal waste pill.

WANG Lei, ZHANG Yu-jie, YU Ya-jun

2019, 38(12):  3717-3722. 

Asbtract ( 287 )   PDF (537KB) ( 92 )  

Soil organic carbon and its active components represent soil fertility and are sensitive to changes of soil quality. This study examined soil organic carbon and its influencing factors under different reclaimed vegetations of coal waster pile. Findings from this study are of great significance to ascertain the quality and fertility of reclaimed soil and to guide the selection of vegetation types for the reclamation of coal waster pile. The concentrations of total soil organic carbon (SOC), dissolved organic carbon (DOC), watersoluble organic carbon (WSOC), microbial biomass carbon (MBC), light fraction organic carbon (LFOC), and heavy fraction organic carbon (HFOC) in 0-10 cm and 10-20 cm soil layers were measured in two land types (grassland and woodland reclaimed for nine years) of Caocun coal waste pile in Huozhou, Shanxi Province. The relationships between soil organic carbon content and soil environmental factors were analyzed. The results showed that: (1) SOC and HFOC contents in grassland were 26.1% and 70.5% higher than that in woodland, and the LFOC contents was 53.1% lower, while the DOC, WSOC and MBC were similar in both vegetation types. This result indicated that the concentrations of SOC in grassland was higher than that in woodland, and such increment was mainly embodied by HFOC content. There was no significant difference in the active components of SOC. (2) Soil TN, TP, AN, C/N, clay content, and pH affected SOC and its active components. Specifically, soil TN, AN, TP, and pH were the key factors influencing SOC and its components under both vegetation types. Therefore, improving soil N, P and reducing soil pH may promote the accumulation of soil organic carbon in reclaimed soil in coal waster pile.

The phytoextraction ability of 54 woody species on Cu, Pb, Zn in soil.

SHANG Kan-kan, ZHANG Guo-wei, JIANG Yun

2019, 38(12):  3723-3730. 

Asbtract ( 238 )   PDF (682KB) ( 50 )  

Woody plants play an important role on phytoremediation of heavy metal contaminated soil during urban greening. In this study, the ability of 54 woody species on phytoextraction of Cu, Pb and Zn in soil were evaluated with pot experiment. The results showed that the contents of Cu (22.91-370.96 mg·kg^-1), Pb (0.21-27.00 mg·kg^-1) and Zn (25.03-539.02 mg·kg^-1) in roots of woody plants were significantly higher than the aboveground parts. Cu and Zn contents in aboveground parts of 11 and 15 woody species exceeded 30 and 150 mg·kg^-1 respectively, while only Robinia pseudoacacia had a Pb content more than 10 mg·kg^-1. There were 16 woody species with strong phytoextraction ability for Zn, but few species with phytoextraction ability for Cu and Pb. With comprehensive evaluation, Fraxinus chinensis, Callicarpa dichotoma, Lagerstroemia indica,Rhus chinensis, Sambucus williamsii,R. pseudoacacia, Liquidambar formosana, Broussonetia papyrifera,Idesia polycarpa and Viburnum odoratissimumhad strong ability of phytoextraction of heavy metals from soil. F. chinensisis an ideal tree species for phytoremediation of urban soil polluted by Cu, Pb and Zn.

Dynamic comparison of Pb accumulation in the ancient tree-rings ofMagnolia grandiflora and Ailanthus altissima.

ZHANG Qian-jin, LIU Hua, SU Shou-xiang, WANG Jia-nan, WU Ze-min

2019, 38(12):  3731-3737. 

Asbtract ( 228 )   PDF (891KB) ( 307 )  

Pb pollution, an important type of urban environmental pollution, affects environmental quality and human health and thus has received many concerns. In this study, Pb accumulation in tree rings of Magnolia grandiflora and Ailanthus altissima, two common garden tree species in Hefei City, was measured to understand the temporal dynamics of urban Pb pollution and the underlying reason. The results showed that the average Pb concentration was 1.114±0.055 mg·kg^-1  in the tree rings of Magnolia grandiflorafor 110 years and 0.667±0.037 mg·kg^-1 in Ailanthus altissimafor 60 years. The variations of Pb concentrations in the tree rings of both species showed substantial fluctuation and great similarity. For most of the tree rings, Pb concentrations were at a lower level. The peak of both tree species appeared in the same period. Pb concentration had no significant correlation with tree age and ring width, but was well correlated with annual average precipitation corresponding to tree ring segments, with correlation coefficients of 0.89 and 0.84, respectively. The variation pattern of Pb concentration in both species reflected the historical Pb pollution. The years with Pb concentration in the tree rings higher than the average concurred with war, urban economic growth, and/or urban expansion. During the period of study, the overall trend Pb accumulation in tree rings showed a downward trend, and such trend was significantly greater for Ailanthus altissima than for Magnolia grandiflora.

MiRNA172b-5p, miRNA172e-5p and miRNA472-3p responded to Cd stress by targeting MSH6 gene in Arabidopsis thaliana.

CHENG Zhi-bo, WANG He-tong, ZHAO Qiang, ZHANG Yan-zhao, JIA Chun-yun, HE Lei, CUI Wei-na, TAI Pei-dong, LIU Wan

2019, 38(12):  3738-3746. 

Asbtract ( 269 )   PDF (836KB) ( 68 )  

MSH6 plays an important role in the activation of checkpoints in cell cycles and in repairing of DNA damage under Cd stress. In this study, we found that MSH6 gene had targeting sequence of microRNAs (miRNAs), including miRNA172b-5p, miRNA172e-5p and miRNA472-3p in Arabidopsis thaliana by bioinformatics analysis. The results of dual luciferase reporter assay showed that miRNA172b-5p, miRNA172e-5p, and miRNA472-3p significantly reduced the related luciferase activity of reporter construct, which was decreased by 25.5%, 47.2% and 49.5%, respectively, compared with the negative control group in an Agrobacterium tumefaciensmediated in vitro assay (P<0.01). Results from Arabidopsis thaliana leaves injected transient expression in vivo assay showed that the over-expression level of miRNA172b-5p, miRNA172e-5p and miRNA472-3p was 178.9%, 123.6% and 37.6%, respectively. Results of qRT-PCR(real time quantitative reverse transcript polymerase chain reaction) showed that the expression of MSH6 was decreased by 20.3%, 22.7% and 38.2% in Arabidopsis thaliana leaves when exposed to 1.25, 2.5, 4.0 mg·L^-1 Cd stress for seven days, but the expression levels of miRNA172b-5p, miRNA172e-5p and miRNA472-3p were enhanced. There were negative relationships between these three miRNAs and MSH6gene (r=-0.995, P<0.01; r=-0.995, P<0.01; r=-0.984, P<0.05), indicating that miRNA172b-5p, miRNA172e-5p and miRNA472-3p were Cd responsive miRNAs and could directly target toMSH6 gene in Arabidopsis thaliana. Ourresults provide theoretical basis of miRNA for the study of Cd toxicological mechanism regulated by DNA mismatch repair (MMR) system.

Effects of weathering of Qingxudong formation on heavy metal accumulation in soil in karst area.

CHEN Zhuo, WU Pan, MENG Wei, ZENG Xiang-ying

2019, 38(12):  3747-3753. 

Asbtract ( 232 )   PDF (858KB) ( 71 )  

To clarify the distribution characteristics and sources of heavy metals in soil weathered from the Cambrian Qingxudong formation in karst area, overlying soil samples, including surface soils and profile soils, were collected from Qingxudong formation in Kaiyang, Songtao, Bijiang, Zhenyuan, Taijiang, Kaili, and Duyun. The concentrations of heavy metals and trace elements in the soils were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that the concentrations of Cd, Cr, Cu, Ni, Pb and Zn in surface soils were 3.46, 77.98, 34.83, 48.66, 90.18, 562.78 mg·kg^-1, respectively. Heavy metals in the surface soil showed obvious accumulation characteristics, with cumulative degree of Cd>Pb>Zn>Ni>Cu>Cr. Heavy metals in soil profiles were characterized by significant accumulation of Cd, Pb and Zn at the bottom. The main accumulative elements Cd, Pb and Zn were closely related to the leadzinc mineralization of Qingxudong formation.

Ecotoxicological effects of triclosan on Hydrilla verticillatain water.

ZHANG Li-na, WANG Zhi-yin, AN Jing, LI Ru

2019, 38(12):  3754-3761. 

Asbtract ( 301 )   PDF (788KB) ( 74 )  

As triclosan (TCS) is detected continuously in water samples recently, more and more attentions focus on its toxic effects in aquatic ecosystems. Toxicology experiment methods were used to investigate the ecotoxicological effects of low concentration TCS on Hydrilla verticillata, a typical submerged plant, during a longterm exposure time. The results showed that TCS was detected in H. verticillata with the exposure of 0.05-0.5 mg·L^-1 TCS in 28 d. The highest concentration of TCS in H.verticillata was detected in the 0.1 mg·L^-1 TCS treatment. Compared with that in the control, foliar chlorophyll content of H. verticillatashowed a trend of inhibitionpromotioninhibition during the whole exposure period, while the chlorophyll content of stems was significantly inhibited at the early stage and increased gradually at the end of exposure stage. The content of soluble protein in the leaves showed a promotioninhibitionpromotion trend, while that in stems showed a trend of promotion and then inhibition. The antioxidant defense system of H. verticillata was disturbed by TCS, with the destructive effect of TCS on the antioxidant enzymes in leaves and stems of plants being significantly different. Our results provide toxicological data and theoretical basis for effective assessment of the ecological risk of TCS in water environment.

Suitability index construction and weight analysis for the spawning ground of Oncorhynchus keta.

CUI Kang-cheng, LIU Wei, GAO Wen-yan, LI Pei-lun, WANG Ji-long, TANG Fu-jiang

2019, 38(12):  3762-3770. 

Asbtract ( 234 )   PDF (571KB) ( 179 )  

Spawning ground is an important place for the survival and reproduction of aquatic organisms. At different stages of life history, Oncorhynchus keta has different requirements for environmental factors. Based on the data of water quality, hydrology and aquatic organism survey during the breeding, hatching and migrating period of salmon in the lower reaches of Huma River from autumn 2017 to spring 2018, we used the fuzzy membership function and analytic hierarchy process to standardize the calculation and weight assignment of the environmental indices of salmon spawning ground. We established the evaluation model of salmon spawning ground to compare the suitability across different seasons. The results of standardization showed that water quality and hydrological factors in the lower reaches of the Huma River could better meet the environmental requirements of salmon spawning grounds. Weight analysis results showed that water temperature, dissolved oxygen, and sediment were the most important factors affecting the suitability of salmon spawning grounds in the lower reaches of the Huma River, followed by ammonia, pH and water depth, in autumn, winter, and spring. The results of the evaluation model showed that the suitability index of salmon spawning grounds in autumn, winter and spring were 0.839, 0.652 and 0.743, respectively. Our results indicated that the eco-environment suitability of salmon spawning grounds in the study region was good, with the best in autumn, followed by spring, and worse in winter.

Kármán gait of aCarassius auratus swimming in the wake of a circle cylinder.

WANG Kai-hui, JI Ru-xuan, LIU Zhe-heng, WANG Si-ying

2019, 38(12):  3771-3778. 

Asbtract ( 369 )   PDF (1420KB) ( 139 )  

The response mechanism of fish swimming to the surrounding flow environment is important to ecological protection and bionic application of fishes. Using the high speed video experimental technology and ANSYS FLUENT numerical simulation software, we observed the kinematic behaviors of Carassius auratus swimming in the wake of a circle cylinder. Their movements in uniform flow were also studied using comparative analysis. By analyzing the variation of body profiles during fish swimming, the parameters such as the tail-beat frequency, head-swing angle, flapping amplitude, and wavelength and wave speed of the body deformation were measured. Their dependency on factors such as flow speed and flow structure was assessed. The results showed that the carps may exploit a Kármán gait to hold their stations in the Kármán vortex street. Whether they exploit this special gait or not was related to the intensity and shedding frequency of the vortices. During the Kármán gait, the carp synchronized its movement with the vortex street, with the flapping frequency equals to the vortices shedding frequency. Compared with that in a uniform flow with equivalent flow velocity, the head-swing angular and the flapping amplitude of the whole body were much larger, the tail-beat frequency was lower, and the wavelength and wave speed of the deformation of the fish were larger. Our results deepen our understanding of fish swimming mechanism and provide basic support for bionic application and ecological protection of fishes.

Relationship between landscape pattern and hydrochemical characteristics of Binggou River Basin in eastern Qilian Mountains.

ZHOU Jun-ju, XIANG Juan, WANG Lan-ying, ZHONG Guo-shuang, ZHU Guo-feng, WEI Wei, FENG Wei, HUANG Mei-hua

2019, 38(12):  3779-3788. 

Asbtract ( 338 )   PDF (1560KB) ( 67 )  

Based on the data of land use and hydrochemistry of river water in the Binggou River Basin in September 2016, buffers at three scales were established by the center of the water sampling points. The landscape index was calculated by Fragstats 4.2. The relationship between landscape pattern and hydrochemistry at different scales was analyzed by redundant analysis method. The results showed that different land use/cover types had different effects on chemical characteristics of river water. Increased area of farmland and construction land promoted the major chemical elements to be converged into river water. Grassland retained water chemical elements, whereas water area and desert had dilution effects. Forest land was positively related to water chemical characteristics in the upper reaches. Patch density, landscape division index, and patch cohesion index were good indicators for water chemistry at the scale of 200 m and 600 m in the Binggou River Basin. The relationships of the areaweighted patch fractal dimension at 1000 m buffer scale and the landscape shape index at 600 m scale with the water chemistry characteristics accorded with the objective law. The Shannon’s diversity index at the 600 m buffer scale in the middle and lower reaches of this basin could better indicate water chemistry characteristics. Our results revealed the ecological hydrological processes in the Qilian Mountains and thus provide reference for the rational use of land and the optimization of landscape pattern.

Identification of drivers for water yield in the upstream of Shiyang River based on InVEST model.

ZHAO Ya-ru, ZHOU Jun-ju, LEI Li, XIANG Juan, HUANG Mei-hua, FENG Wei, ZHU Guo-feng, WEI Wei, WANG Jing-ai

2019, 38(12):  3789-3799. 

Asbtract ( 658 )   PDF (2028KB) ( 220 )  

Shiyang River basin, located in the inland of northwest China, is an ecologically fragile area with water shortage and prominent environmental problems. Understanding the upstream water production process of Shiyang River can provide scientific reference for regional sustainable development. Based on InVEST model, we evaluated annual water yield in the upstream of Shiyang River in the past 30 years with soil, meteorological and land use data in 1986, 2000, 2010 and 2015 as inputs and applied scenario simulation method to explore its response to climate and land use changes. The results showed that areas with high water yield in the upstream of Shiyang River were concentrated in the west and southwest regions. Among the eight major river systems, Xiying River had the largest water yield depth (220.97 mm) and the highest water yield capacity (46.05%). The unutilized land had the highest water production capacity (55.49%), followed by grassland (34.52%), cultivated land (33.27%), and woodland (31.59%). From 1986 to 2015, water yield in the upstream of Shiyang River showed a change pattern of increase first, then decrease, and then slow increase. The changes of the eight major river systems were significantly different. Climate change, especially precipitation change, is the main factor affecting the changes of water yield. Land use change affected actual evaporation by changing underlying surface condition, with consequence on water yield.

 

Spatiotemporal evolution pattern and influencing factors of eco-environmental quality in Gansu from 2000 to 2017.

SONG Yuan, SHI Hui-chun, XIE Min-hui, ZHAO Peng-xia

2019, 38(12):  3800-3808. 

Asbtract ( 424 )   PDF (1558KB) ( 214 )  

With RS and GIS, spatial principal component analysis was used to construct the eco-environmental quality index of Gansu, a region with relatively fragile eco-environment, by selecting 11 indicators including natural and anthropogenic factors. The spatiotemporal distribution and influencing factors of eco-environmental quality were analyzed. The results showed that eco-environmental quality in 2000 and 2017 showed a polarization phenomenon in term of spatial distribution. The areas with poor and fair grades of eco-environmental quality were mainly concentrated in northwest Gansu, while the areas with good and excellent grades of eco-environmental quality were mainly concentrated in southeast Gansu. Temporally, there was a trend of improvement for eco-environmental quality in the past 17 years. Generally, climate, vegetation cover, land use type, and soil matrix were dominant factors affecting eco-environmental quality, while the role of population economy, landform and hydrological environment were relatively minor.

Evolution of land-use and land-cover change and surface thermal environment in rural area: A case of the typical rural areas in Xuzhou.

XIA Jia-nan, JING Hui-xia, LI Xiao-shun

2019, 38(12):  3809-3819. 

Asbtract ( 365 )   PDF (3778KB) ( 109 )  

With the rapid industrialization and urbanization, rural construction land has gradually occupied the ecological space and changed the thermal environment of land surface. Ecological security has become an increasingly important problem. Taking the rural area which is surrounded by S271 Provincial Highway, S252 Provincial Highway, Lianhuo Highway and S323 Provincial Highway of Xuzhou as an example, we investigated the temporal and spatial changes of temperature of rural land surface, and elucidated the evolving features of LUCC (land-use and land-cover change) and the thermal environment of land surface by constructing prediction functions of thermal effect with land use/cover. There were obvious dynamic differences in land surface temperature in the study area. When the historical temperature of Pizhou was below 10 ℃, surface temperature of cultivated land reached the highest and the residential area was the lowest. When the temperature was between 10 ℃ and 24 ℃, there was subtle difference of surface temperature among all land use types, which was less than 1 ℃. When the temperature was over 24 ℃, the surface temperature of the residential area was the highest while forest land was the lowest. In reference to the evolving features of rural land use, it mainly manifests that the forest land is occupied by both residential area and cultivated land. The evolution is mainly concentrated on the adjacent land plots of the traffic land. In reference to the evolution features of the surface thermal environment under the evolution of rural space, land evolution which mainly attributes to the expansion of residential areas has significantly enhanced the sensitivity and seasonal variation of temperature change in the study area. The thermal environment variation of land surface, which is caused by rural spatial evolution, will be effectively weakened by increasing the proportion of surface vegetation cover of forest land.

Landscape scenic beauty of traditional Dong Minority villages in southeast of Guizhou Province.

FENG Wei-wei, HUANG Zong-sheng, ZHANG Yuan-bo, LIU Yi-fu, PANG Min

2019, 38(12):  3820-3830. 

Asbtract ( 297 )   PDF (2031KB) ( 176 )  

To facilitate the protection and development of traditional villages, scenic beauty estimation procedures (SBE) and semantic differential (SD) method were used to study the scenic beauty of traditional villages of Dong Minority in Southeast Guizhou. The results showed that a decreasing trend of SBE value was found in the overall landscape, farmland, vegetation, buildings, water body, and roads. Significant differences of SBE value were found among the overall landscape and buildings, water body and roads (P<0.05), but not among the overall landscape and farmland and vegetation. There was no significant difference among buildings, water body and roads or between farmland and vegetation. The main factors influencing the scenic beauty of the villages included environmental quality, stratification of landscapes, landform, architectural features (architectural texture, building quality, architectural appearance, architectural colors and architectural shape), water quality, morphological features of shorelines, area of the farmland, growth conditions of crops, spatial composition and morphological characteristics of plant communities, growth conditions and color of plants, road pavement, road curvature and psychological feelings that roads bring to people. The aesthetic features of the Dong Minority villages were mainly embodied by the beauty of ecological harmony, spatial form of cultural elements (buildings, roads, and water body), functional practicality and ethnic culture. Combined with landscape planning and protection techniques, the scenic beauty threshold method could be used as an auxiliary means to the quantitative study of traditional villages landscape protection planning. Based on such findings, we proposed that it is necessary to implement targeted protection by the principle of adopting protective measures according to classification for the protection of traditional village landscapes from the perspective of key influencing factors. Our results can be used to improve the traditional village landscape protection planning, optimize the villages’ spatial layout, and protect the ancient village style and idyllic landscape, thus would help maintain the landscape aesthetic value. Furthermore, our results provide reference for the quantitative study of aesthetic characteristics of traditional village landscapes, the protection and development of traditional villages, and the construction of modern village landscapes with Dong ethnic characteristics.

Research prospect of all-round controlling technology system constructing and resource-based utilization of Pomacea canaliculata in paddy fields.

ZHANG Jia-en, GUO Jing, ZHAO Ben-liang, QIN Zhong

2019, 38(12):  3831-3838. 

Asbtract ( 367 )   PDF (619KB) ( 152 )  

Golden apple snail, Pomacea canaliculata, has invaded to China for nearly four decades, and caused serious harm to rice production in the southern regions of Yangtze River. Some palliative and surface strategies have been used to control P. canaliculata, including locally separate control, temporary control in crop growing season, single countermeasure control, and individual farming household control. All those method showed no good controlling effect on golden apple snail, the invasion of which is becoming more and more serious. Here, we put forward an all-round comprehensive controlling technical system which covers whole watershed, whole farming process, all-time and all-weather, and all-measures. Meanwhile, from the beginning to post-harvest of rice production, related key techniques and methods to control the snail were summarized and reviewed. Finally, we proposed research prospects on innovations in prediction, warning and emergency prevention and controlling system of snail breakout, environment-friendly controlling techniques, and key techniques for resource-based use of P. canaliculata.

Application of geographic information technology in terrestrial mammal habitat research: Retrospect and prospect.

ZHANG Wen-han, CHI Yao, QIAN Tian-lu, XI Chang-bai, WANG Jie-chen

2019, 38(12):  3839-3846. 

Asbtract ( 279 )   PDF (527KB) ( 132 )  

The flourishing development of geographic information technologies, with their powerful spatial data processing capability, provide strong support for researches on the habitats of terrestrial mammals, and have been widely used in related research area. We reviewed the research works on the habitats of terrestrial mammals in recent decades, and summarized the existing applications from aspects of habitat data acquisition and management, spatiotemporal data processing and analysis, and habitat planning and evaluation. In the final part, for each link of data acquisition, data management, analysis methods, and information expression, we proposed possible development trend for the application of geographic information technologies in the field of terrestrial mammal habitats.

Research progress of phytolith and phytolith-occluded organic carbon in forest ecosystems.

LI Shuang, SHENG Mao-yin

2019, 38(12):  3847-3853. 

Asbtract ( 1493 )   PDF (481KB) ( 610 )  

As the main part of terrestrial ecosystems, forest ecosystem is a renewable circulation system. In its evolution course, forest ecosystem stored a large number of the information of environmental changes, and plays an important role in the global carbon sink. Phytolith-occluded carbon (PhytOC) is considered as a pathway of longterm carbon sequestration in forest ecosystem. Research of phytolith and PhytOC in forest ecosystems is of great significance to estimate the long-term carbon sequestration potential of forest ecosystems and to address global warming. Here, we reviewed the differences in the content and existing forms of phytolith and PhytOC in plant, litter and soil, and their migration dynamics. The turnover and content of phytolith and PhytOC among different channels are stable as they are affected by both internal and external factors. Quantitative information on phytolith and PhytOC is lacking, especially for ecologically fragile areas. In the future, it is necessary to strengthen the study on the formation mechanism of phytolith and PhytOC, estimate carbon sequestration of different organs of plants, enlarge spatial and temporal scales, and intensify the study of PhytOC in ecologically fragile areas, so as to provide reference for accurate estimation of carbon sequestration in phytoliths in forest ecosystems.

Research progress on mineral carbonation of carbon dioxide. 

MA Ming-jing, XI Feng-ming, LING Jing-hua, WANG Jiao-yue, QUAN Shi-miao

2019, 38(12):  3854-3863. 

Asbtract ( 699 )   PDF (845KB) ( 347 )  

Carbon capture and storage (CCS) technology is an important way to cope with global climate change and reduce atmospheric carbon dioxide. Among all the technology, mineral carbonation technology (MCT) is the most safe, permanent, and environment-friendly way. We summarized MCT from the aspects of the reaction principle, raw materials, technical routes and impact factors. Mineral storage is greatly affected by pressure, temperature, pH, particle size, and raw materials. Each process differs in carbon storage capacity and operation cost. Wet carbonization process is the most promising one for industrialization. Among all the carbon storage materials, industrial alkaline waste is an ideal carbon storage material due to its high reactivity, low cost and easy access. Although MCT has a promising future, it is still at the laboratory research- stage. This review will provide reference for the selection of technologies coping with climate change. Future research should be strengthened from the following aspects: upgrading CO₂ separation and purification technology, improving carbonization storage technology, accelerating the rate of carbonization reaction, reducing carbon capture and storage costs, and promoting large-scale commercial application of mineral carbonation technology.

Estimation of leaf nitrogen content of main tree species in the secondary forest of Northeast China based on Fourier mid-infrared spectroscopy.

MIAO Chen, XU Shuang, ZHANG Jin-xin, YANG Kai

2019, 38(12):  3864-3869. 

Asbtract ( 289 )   PDF (1679KB) ( 80 )  

In this study, the main tree species in the secondary forest ecosystem of Northeast China were selected, including Betula costata, Juglans mandshurica, Fraxinus rhynchophylla,Ulmus laciniata,Quercus mongolica,Acer mono, Populus davidiana, Fraxinus mandschurica,Tilia amurensis, and Tilia tuan. Leaf total nitrogen content of the 10 tree species and their Fourier mid-infrared spectroscopy in the range of 4000-400 cm^-1 were analyzed. The relative peak height of the Fourier midinfrared spectroscopy of leaves was used to semi-quantitatively predict leaf total nitrogen content of tree species. Based on analysis results of the bands with obvious peak such as 3430-3350, 2930-2910, 2860-2850, 1740-1720, 1660-1610, 1460-1420, 1380-1310, 1270-1230, and 1080-1030 (all measured by cm^-1), total nitrogen contents in leaves ranged from 11.9 to 72.6 g·kg^-1. The total nitrogen content of leaves was correlated with the relative peak height of the bands 3430-3350 cm^-1, with a correlation coefficient of 0.690 (P<0.01). These results suggested that leaf total nitrogen content of tree species can be quickly quantified by the relative peak height of the Fourier midinfrared spectroscopy of 3430-3350 cm^-1 band in the secondary forests of Northeast China. Leaf total nitrogen content may be related to N-H bands at 3430-3350 cm^-1 in this area. In the future study, prediction of leaf total nitrogen content of tree species by Fourier mid-infrared spectroscopy can be used as a suitable method.

Diversity of vegetation coverage based on birds’ habitat demands in the coastal wetland of Yancheng, Jiangsu Province.

REN Wu-yang, WANG Cheng, LIU Hong-yu, LI Yu-feng, ZHOU Yi, XU Jia-yi, CHEN Hao

2019, 38(12):  3870-3877. 

Asbtract ( 318 )   PDF (2428KB) ( 88 )  

The diversity of wetland landscape coverage provides a wide range of habitat selection for birds, which is important for the maintenance of wetland bird diversity. Based on GF₂ images, the habitat types of wetland vegetation were extracted using object oriented classification method. The coverage of wetland vegetation was calculated using dimidiate pixel model. According to the range of coverage fluctuation, five coverage types were divided in the study area. Finally, the statistical analysis on the coverage of different vegetation was performed. The results showed that, compared with the traditional supervised classification method, the overall accuracy of object oriented classification was higher, reaching 91.21%. The wetland vegetation interpreted by remote sensing showed obvious zonal distribution, with the main habitats being reed marsh, Suaeda salsa marsh, and Spartina alterniflora marsh. The distribution pattern of vegetation coverage was high on all sides and low in the center, with differences among various dominant vegetation coverage types. Among them, reed marsh mainly distributed in the superior coverage area and high coverage area, Spartina alterniflora marsh mainly distributed in the high coverage area, andSuaeda salsa marsh mainly distributed in the superior coverage area, which accounted for 45%, 25% and 7.72% of the total vegetation area, respectively.

Eco-economic rationality of fertilization and the potential of fertilizer reduction in Henan Province based on threshold model.

LIU Qin-pu, PU Li-jie, SUN Jing-rong

2019, 38(12):  3878-3886. 

Asbtract ( 310 )   PDF (786KB) ( 108 )  

Based on mathematical models and data of 1980-2017, environmental thresholds of fertilization in Henan Province and its prefectural-level cities were calculated to evaluate the eco-economic rationality of fertilization for reducing fertilizer use and improving the sustainable agricultural development. The results showed that environmental threshold of fertilization in Henan-increased from 104 kg·hm^-2 in 1980 to 266 kg·hm^-2 in 2017 and fertilization eco-economic rationality index changed from 0.72 in 1980 to 1.00 in 1988 to 0.16 in 2017 with alterations of fertilization rationality from relatively rational to rational to severely irrational. Hebi was only one city among the 18 prefecturallevel cities in Henan which belonged to the relatively rational for fertilizer use with the amount being less than 30% of fertilization environmental safety threshold in 2017. 15 cities belonged to the severely irrational for fertilizer use with the amount more than 50% of the thresholds in Henan, except for Kaifeng and Xinyang. For the use of single fertilizer in Henan, phosphorus was severely irrational, nitrogen was irrational, and potassium was slightly irrational. According to the thresholds, 3.1 million tons of fertilizers could be reduced, including 1.28, 1.15, and 0.66 million tons of nitrogen, phosphorus, and potassium fertilizers, respectively. There is a great potential for Henan to reduce the overused fertilizers and a huge task to assure the win-win development of grain security and friendly environment.

Effects of bentonite-humic acid on gaseous nitrogen loss, nitrogen use efficiency and maize yield on sandy soil.

ZHENG Yi, ZHOU Lei, LIU Jing-hui

2019, 38(12):  3887-3894. 

Asbtract ( 302 )   PDF (626KB) ( 78 )  

We examined the effects of bentonitehumic acid on soil NH₃ volatilization and N₂O emission, nitrogen use efficiency and maize yield on sandy soil in West Liaohe River plain. There were five treatments: CK (no nitrogen and bentonite-humic acid application), B₀ (bentonitehumic acid only, 30 t·hm^-2), N₀ (nitrogen only, 160 t·hm^-2), NB₂ bentonite humic acid, 30 t·hm^-2; nitrogen, 160 t·hm^-2), NB₂ (bentonite humic acid, 60 t·hm^-2; nitrogen, 160 t·hm^-2). Results showed that gaseous nitrogen loss mainly came from NH₃ volatilization, followed by N₂O emission. The dynamics of NH₃ volatilization and N₂O emission during maize growth varied among treatments: the CK and B₀ showed a steady change, but the nitrogen treatments had a rapid increase and dropped down quickly, then remained unchanged. Compared to CK, B₀ had no significant effect on soil gaseous nitrogen loss, but significantly increased maize grain yield (P≤0.05). Addition of bentonite humic acid and nitrogen deceased soil gaseous nitrogen loss, and enhanced nitrogen use efficiency and maize yield and protein content. The NB₂ treatment showed the best performance in reducing gaseous nitrogen loss, but its nitrogen use efficiency and maize yield were lower (P≤0.05) than N₀. NB treatment had the highest nitrogen use efficiency, maize yield and grain protein content, which increased by 21.31%, 8.66% and 40.03% respectively, compared to N₀. In conclusion, addition of bentonite-humic acid on sandy soil could reduce soil gaseous nitrogen loss, increase nitrogen use efficiency and yield of maize, and improve grain quality. Our results provide a new way for improving nitrogen use efficiency and amelioration of sandy soil.