当前位置: X-MOL 学术J. Trop. Ecol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Landscape forest loss changes sunfleck dynamics in forest fragments of southern Bahia, Brazil
Journal of Tropical Ecology ( IF 1.4 ) Pub Date : 2021-06-09 , DOI: 10.1017/s0266467421000110
Igor Pires Reis , Larissa Rocha-Santos , Adrielle Leal , Deborah Faria , Marcelo Schramm Mielke

Landscape-scale habitat loss can change the floristic composition of forest fragments, affecting the survival of specific groups of plants, as shade-tolerant and emergent trees. This increasing in tree mortality creates forest canopy gaps of different sizes that ultimately determine the solar radiation available in the forest understorey. We conducted a study aiming to assess how the loss of forest cover at landscape level (i.e. deforestation) affects the sunfleck dynamics, a proxy of light regime in forest understorey. We expected that fragments located in landscapes with less forest cover have a high number of larger canopy gaps and, consequently, long-lasting sunflecks. In each forest fragment, a 100 per 50 m plot was established, and in each plot, we took 10 hemispherical photographs. The images were analysed using the Gap Light Analyzer software. The sunflecks were divided into six temporal classes. We evidenced that landscape-scale deforestation increased the frequency of all sunfleck intervals >8 min, particularly the long-lasting (> 32 min) sunflecks. We propose that the increasing frequency of long-lasting sunflecks reduces suitability of microhabitat to some shade-tolerant species in local fragments, a potential proximal mechanism contributing to compositional shifts of tree assemblages observed in forest fragments within deforested landscapes.

中文翻译:

景观森林损失改变了巴西巴伊亚南部森林碎片的阳光斑动态

景观规模的栖息地丧失会改变森林碎片的植物区系组成,影响特定植物群的生存,如耐荫和挺水树木。树木死亡率的增加造成了不同大小的森林冠层间隙,最终决定了森林下层可用的太阳辐射。我们进行了一项研究,旨在评估景观层面森林覆盖的丧失(即森林砍伐)如何影响 sunfeck 动态,这是森林下层光照状态的代表。我们预计位于森林覆盖较少的景观中的碎片具有大量较大的树冠间隙,因此会产生持久的阳光斑点。在每个森林碎片中,每 50 m 建立 100 张样地,在每个样地中,我们拍摄了 10 张半球形照片。使用 Gap Light Analyzer 软件分析图像。太阳斑点分为六个时间类别。我们证明了景观规模的森林砍伐增加了所有大于 8 分钟的阳光斑间隔的频率,特别是持久(> 32 分钟)的阳光斑。我们提出,长期存在的阳光斑的频率增加会降低微生境对局部碎片中某些耐荫物种的适用性,这是一种潜在的近端机制,有助于在毁林景观中的森林碎片中观察到树木组合的组成变化。
更新日期:2021-06-09
down
wechat
bug