Roshan Zahra Sepehri, Anushiravani Sina, Karimi Soroor, Moradi Hossein Varasteh, Salmanmahini Abdol Rasoul
Environmental Sciences Department, Gorgan University of Agriculture and Natural Resources, Gorgan, Iran.
Young Researchers and Elite Club, Gorgan branch, Islamic Azad University, Gorgan, Iran.
Environ Monit Assess. 2017 Feb;189(2):66. doi: 10.1007/s10661-017-5778-9. Epub 2017 Jan 21.
Every stage of succession may provide certain species with habitat requirements which are impossible in other stages of succession. This study attempts to evaluate the different stages of succession in terms of composition and structure of bird populations in Hyrcanian forests. Bird-habitat relationships were investigated by comparing vegetation characteristics in three successional stages including late, initial stage, and urban areas. Bird richness, diversity, and abundance were measured within a 25-m radius of each of the 120 sampling points in various stages of succession and urban areas from May to April (2014) in the Ziarat catchment. This study indicated that every stage of succession may support certain species. Based on bird-habitat associations along the various stages of succession, two groups were distinguished. Conventional comparative analysis separated two groups of understory birds: interior specialists and edge specialists. The interior-specialist group was positively correlated with the number of dead trees, tall trees with high values of dbh and height and canopy cover. In contrast, edge specialists groups mainly included terrestrial insectivores and were positively correlated with open area and shrub cover, and percentage of shrub cover between 1 and 2 m in height. In summary, bird communities in Hyrcanian forests are highly dynamic in different vegetation covers suggesting that it is critical to increase diverse and abundant bird populations by conserving forests composed of mosaics of differently disturbed stands and mature forest patches.
演替的每个阶段都可能为某些物种提供在演替的其他阶段无法满足的栖息地需求。本研究试图根据里海森林鸟类种群的组成和结构来评估演替的不同阶段。通过比较包括后期、初期和城市地区在内的三个演替阶段的植被特征，研究了鸟类与栖息地的关系。在2014年5月至4月期间，在齐亚拉特集水区不同演替阶段和城市地区的120个采样点，每个采样点半径25米范围内测量鸟类的丰富度、多样性和丰度。本研究表明，演替的每个阶段都可能支持特定的物种。根据演替各阶段的鸟类与栖息地关联，区分出两组。传统的比较分析将林下鸟类分为两组：内部专家型和边缘专家型。内部专家型组与死树数量、胸径和高度值较高的高大树木以及树冠覆盖率呈正相关。相比之下，边缘专家型组主要包括陆生食虫动物，与开阔地、灌木覆盖以及高度在1至2米之间的灌木覆盖百分比呈正相关。总之，里海森林中的鸟类群落在不同植被覆盖下具有高度动态性，这表明通过保护由不同干扰程度的林分和成熟森林斑块组成的马赛克状森林来增加多样且丰富的鸟类种群至关重要。
