Conversion of natural habitat into agricultural landscape has been identified as one of the major drivers of habitat loss. Human-modified ecosystems, such as agricultural land, have gained significant attention in terms of the conservation of their native biodiversity. We studied the effectiveness of organic agroecosystems in conserving odonate diversity by comparing organic terrace rice cultivation with a nearby natural forest system with streams in Sikkim, Eastern Himalaya, India. We sampled adult odonates using a transect count method (laying six permanent transects) covering two villages (Lingmoo in South Sikkim and Dzongu in North Sikkim), making a total of 48 transect counts. A total of 881 individual odonates representing 31 species under two suborders (16 Anisoptera and 15 Zygoptera) and seven families were recorded during this study. Of these, 20 species representing three families and 18 species representing seven families were observed in terrace rice cultivation and the natural forest system, respectively. Beta diversity estimates showed that the community composition of the odonates differed qualitatively (incidence measure) and quantitatively (abundance measure) between the two land use types. Turnover component (abundance balance in case of abundance based beta diversity measure) had higher contribution in the overall beta diversity, suggesting that one assemblage of species is being replaced by another due to environmental sorting. The variation in community composition between the two habitats was statistically significant. Our results suggest that organic wetland habitats are important for conservation of odonates and associated biodiversity (especially herpetofauna) in the Himalaya and require urgent conservation attention.

中文翻译：

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印度喜马拉雅东部锡金地区有机梯田栽培对保护齿科植物的有效性

将自然栖息地转变为农业景观已被确定为栖息地丧失的主要驱动因素之一。人类改造的生态系统，如农田，在保护其原生生物多样性方面受到了极大的关注。我们通过将有机梯田水稻种植与附近的天然森林系统与印度喜马拉雅东部锡金的溪流进行比较，研究了有机农业生态系统在保护齿状藻多样性方面的有效性。我们使用横断面计数方法（铺设六个永久性横断面）对覆盖两个村庄（锡金南部的 Lingmoo 和锡金北部的 Dzongu）的成虫进行采样，总共进行了 48 条断面计数。在这项研究中，总共记录了 881 种个体齿科动物，代表 2 个亚目（16 个异翅目和 15 个接合翅目）和 7 个科下的 31 个物种。其中，在梯田栽培和天然林系统中分别观察到3科20种和7科18种。Beta 多样性估计表明，两种土地利用类型之间的齿类群落组成在质量（发生率测量）和数量上（丰度测量）不同。周转分量（基于丰度的 β 多样性测量的丰度平衡）在整体 β 多样性中具有更高的贡献，这表明由于环境分类，一种物种组合正在被另一种组合所取代。两个栖息地之间群落组成的变化具有统计学意义。