Singh Leimapokpam Amarjit, Ray D C
J Environ Biol. 2015 Jan;36(1):319-23.
The present investigation was carried out in Cachar district of Assam over a period of one year (January 2011 - December 2011) to understand the seasonal ecology of Acarina (Oribatida) in rice (Oryza sativa L.) cultivated fields. Population of Oribatida was found to be maximum during August 2011, both in no-tillage (6.32 ± 0.66 No./m2 x 100(2)) and tillage (5.30 ± 0.71 No./M2 x 100(2)) sites in Dorgakona area whereas the peak was recorded during August 2011, both in no-tillage (5.38 ± 0.75 No./m(2) x 100(2)) and tillage (4.69 ± 0.77 No./m2 x 100(2)) in Durby area of study sites. Least population was encountered during January 2011, in both no-tillage (0.98 ± 0.28 ± No./m2 x 100(2)) and tillage (0.98 ± 0.30 No/m2 x 100(2)) sites in Dorgakona area whereas the same was found during November 2011 in no-tillage (0.57 ± 0.31 No.m/2 x 100(2)) and in February 2011 in tillage (0.45 ± 0.21 No./m2 x 100(2)) sites of Durby area. Linear regression analysis with all the environmental variables showed positive and significant influence on the population dynamics whereas relative humidity (R2 = 0.26 p > 0.05) in Dorgakona no-tillage and tillage (R2 = 0.19 P > 0.05) sites and relative humidity in tillage site (R2 = 0.27 P > 0.05) in Durby area showed no influence. Multiple regression analysis showed that the combined effect of climatic variables having a significant influence (p < 0.05) on the oribatid mite population in no-tillage and tillage systems in both the study sites. Rainfall, relative humidity and temperature facilitated the soil moisture, microbial activity and litter decomposition, which in turn may favour the reproduction and growth rate of the species. Among microclimatic conditions all the parameters showed positive and significant influence (P < 0.05) on the population in no-tillage and tillage system on both the sites except pH which showed negative correlation with the population. One way ANOVA revealed significant difference (F = 6.53, P < 0.01) of the Oribatid population between the systems.
本研究于2011年1月至2011年12月在阿萨姆邦的卡恰尔地区进行，为期一年，旨在了解稻田（水稻）中螨类（甲螨目）的季节生态学。2011年8月，多尔加科纳地区免耕（6.32±0.66只/平方米×100²）和耕作（5.30±0.71只/平方米×100²）地点的甲螨目种群数量均为最高，而在研究地点的德比尔地区，免耕（5.38±0.75只/平方米×100²）和耕作（4.69±0.77只/平方米×100²）的甲螨目种群数量峰值均出现在2011年8月。2011年1月，多尔加科纳地区免耕（0.98±0.28只/平方米×100²）和耕作（0.98±0.30只/平方米×100²）地点的种群数量最少，而在德比尔地区，免耕（0.57±0.31只/平方米×100²）的种群数量最少出现在2011年11月，耕作（0.45±0.21只/平方米×100²）的种群数量最少出现在2011年2月。对所有环境变量进行线性回归分析表明，其对种群动态具有正向且显著的影响，而多尔加科纳地区免耕和耕作地点的相对湿度（R² = 0.26，p＞0.05）以及德比尔地区耕作地点的相对湿度（R² = 0.19，P＞0.05）均无影响。多元回归分析表明，气候变量的综合作用对两个研究地点免耕和耕作系统中的甲螨种群具有显著影响（p＜0.05）。降雨、相对湿度和温度促进了土壤湿度、微生物活动和凋落物分解，进而可能有利于该物种的繁殖和生长速度。在小气候条件中，除pH值与种群呈负相关外，所有参数对两个地点的免耕和耕作系统中的种群均具有正向且显著的影响（P＜0.05）。单因素方差分析表明，不同系统间甲螨目种群存在显著差异（F = 6.53，P＜0.01）。
