关键词: 全球变暖, 粮食安全, 碳排放, 碳足迹

Abstract: Environmental filters play a crucial role in the formation of species diversity patterns. Exploring the relationship between species distribution and environmental factors are important for reasonable management of forests. In this study, we analyzed species abundance, α diversity index, dominant population spatial pattern, and interspecific association with thirty Dacrydium pectinatum fixed plots in Bawangling National Nature Reserve, Hainan Island. A speciesenvironment relationship model (redundancy analysis, RDA) was built through species abundance data and topographic factors data. The results showed that D. pectinatum natural community had a rich species pool, including 187 tree species, 39 shrub species, and 36 herb species. The diversity index exhibited the pattern of tree layer > shrub layer > herbaceous layer, and was significantly higher than the midhigh latitude forest community. The evenness index was low. The species were mostly small-density populations. The importance values of all populations were low, with few dominant species. In addition, 10 dominant populations exhibited a pattern of cluster distribution, and their aggregate intensity and interspecific association were closely related. Results of Spearman analysis showed that the structure and diversity of the natural D. pectinatumcommunity in Bawangling were unstable. There might be intense interspecific competition and frequent species turnover in the future succession. The RDA model results showed that canopy density, elevation and slope aspect were the primary factors affecting species distribution, with dominant effects of canopy density. Our results suggest that some humanassisted measures can be adopted for biodiversity conservation, such as creating forest gaps to increase light utilization rate and reasonable thinning to increase seedling survival.

Key words:  , global warming., food security, carbon footprint, carbon emission