关键词: 籽棉产量, 水氮调控, 土壤硝态氮, 干物质积累, 水氮利用效率

Abstract: Nest predation in ovipara is a primary cause of reproductive failure. To investigate the type of nest predators, predation rates and the effect on breeding success of IndoChinese box turtle (Cuora galbinifrons) in different habitats, we buried eggs of redeared turtle (Trachemys scripta elegans) to simulate IndoChinese box turtle nests at Diaoluoshan village, Diaoluo Nature Reserve  in Hainan Island from March to May 2013. One hundred and twenty artificial nests (two eggs per nest) were evenly placed in plantation forest, secondary forest and primary forest, and triggered cameras were placed around a sample of nests to identify predators. The result indicated that 66.7% nests were depredated, and small mammals (51.3%) and ants (28.8%) were the main predators.  Predation rates in these forests were 72.5%, 62.5% and 62.5% respectively, but the differences were not significant (P>0.05, n=40). In secondary forest, the nest predation rate was higher in forest centers than in forest edges (P<0.05, n=20). No obvious differences were found in nest predation rate between forest centers and edges in plantation forest and primary forest.

Key words: seed-cotton yield, water and nitrogen use efficiency, water and nitrogen arrangement, dry matter accumulation, soil nitrate