Abstract

The Pancheshwar Multipurpose Project proposed for the construction of the largest dam in South Asia is located in the biodiversity rich fragile landscape of the Indian Himalayan Region. In the present scenario, the area at Pancheshwar is being perturbed and going through forest clearance on a regular basis for pre-dam construction operations such as tunnel, road building etc. Butterflies that are vital and crucial organisms for the functioning of terrestrial ecosystems get drastically affected by such large changes in their habitats. The present study therefore aims at describing the importance of butterfly conservation with respect to their diversity and composition along different habitat conditions prevailing at the main dam site of Pancheshwar in the Western Himalaya. Previously, the rich biological diversity of butterflies had remained relatively unknown from the region. By adopting the standardized sampling techniques during 2016–2018, a total of 5341 individuals of 98 species under six butterfly families were recorded from the five representative habitat types (sampling sites) with varying degrees of disturbance. The area was found to be enriched with 23.27% of the known species from the Western Himalaya. Based on global distribution 72.44% of the total recorded species were of the Oriental region, 10.20% species showed Palaearctic distribution while seven species were endemic to the Himalaya. Moreover, the richness and abundance of butterflies varied significantly among the habitat types under various threat levels. The highly disturbed habitat (a forest area altered for pre-dam constructions which was formerly covered with canopy) yielded least diversity and richness while the forest edge habitat in a moderately degraded forest showed the highest diversity, richness and uniqueness, rendering it as a key habitat for preservation and conservation of butterflies. The other three sites selected in the riparian zone had the high similarity of butterfly assemblages. A total of 28 butterfly species were identified on the utmost conservation priorities based on their national protection status, diet specialization, local and global geographic distributions. The high diversity and heterogeneity in community composition is attributed to complex vegetation and diverse habitat conditions prevailing in a fairly isolated geographical area proposed for the mega dam construction.

Implications for insect conservation

At present, declines in the both quality and type of habitats due to the heedless on-going dam construction related activities are causing adverse affects on the rich butterfly diversity and posing paramount threats of habitat loss and extinction to butterfly fauna that include many rare, specialist, legally protected and endemic species of the fragile Himalayan ecosystem. This study thus substantiates the need for adoption of timely specified, decisive and effective conservation practices in such regions of prime biological importance.

中文翻译：

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喜马拉雅西部Pancheshwar的拟议多功能项目影响了丰富的蝴蝶多样性：环境保护

摘要

为建设南亚最大水坝而提出的Pancheshwar多功能项目位于印度喜马拉雅地区生物多样性丰富且脆弱的地区。在目前的情况下，潘切什瓦尔地区受到扰动并定期进行森林砍伐，以进行大坝前的建设活动，例如隧道，道路建设等。对陆地生态系统功能至关重要的重要生物蝶类会急剧增加受其栖息地如此巨大变化的影响。因此，本研究旨在描述在喜马拉雅山西部Pancheshwar主要水坝所在地盛行的蝴蝶栖息地的多样性及其在不同栖息地条件下的组成的重要性。先前，该地区相对未知蝴蝶的丰富生物多样性。通过在2016-2018年间采用标准化采样技术，从五个代表性栖息地类型（采样地点）中，以不同程度的干扰记录了六个蝴蝶科下98个物种的5341个个体。发现该地区富含来自喜马拉雅西部的23.27％的已知物种。根据全球分布，记录的全部物种中有72.44％位于东方地区，有10.20％的物种显示古太平洋分布，而有7种是喜马拉雅特有的。此外，在各种威胁水平下，不同生境类型之间蝴蝶的丰富度和丰度差异很大。受高度干扰的栖息地（以前因大坝覆盖而改建为大坝前建造的森林地区）产生的多样性和丰富性最少，而在中等退化森林中的森林边缘栖息地则表现出最高的多样性，丰富性和独特性，使其成为关键蝴蝶保存和养护的栖息地。在河岸带中选择的其他三个地点具有高度相似的蝴蝶组合。根据其国家保护状况，饮食专长，本地和全球地理分布，共确定了28种蝶类为最高保护重点。

对昆虫保护的意义

目前，由于不加监督的正在进行的大坝建设相关活动而导致的栖息地质量和类型的下降，正在对丰富的蝴蝶多样性造成不利影响，并给栖息地丧失和灭绝带来了极为重要的威胁，其中包括许多稀有的，专业的，脆弱的喜马拉雅生态系统的受法律保护和特有物种。因此，这项研究证实了在具有重要生物学重要性的地区采用及时的，决定性的和有效的保护措施的必要性。