Edge creation changes the timing and intensity of phenological reproductive patterns and species activities in forest tree communities

Abstract Environmental characteristics are among the most important triggers and regulators of plant phenophases, so that the abiotic and biotic changes driven by habitat loss and fragmentation can result in alterations of plant phenological patterns. We investigated whether forest edge and interior have differences in phenological pattern of tree communities. We followed the reproductive phenologies of tree communities in seven forest fragments on a monthly basis for two years (in 200 m² edge and interior plots per fragment). We sampled a total of 0.28 ha of anthropic forest fragments, comprising 313 trees (180 in edge, 133 in interior) belonging to 103 species and 34 families. Our results evidenced reproductive phenological changes between edge and interior tree communities, with: (i) phenological activities differing temporally between the two habitats (edge and forest interior) in all tree communities; (ii) greater phenological intensity at the forest edge than in the forest interior among tree species common to both habitats; (iii) more tree species showed phenological activity at the forest edge in 2010 and interior in 2011, when considering only those exclusive to each habitat. Habitat fragmentation can therefore alter microenvironmental characteristics and influence biologic processes, including the reproductive phenologies of trees, through edge formation.

摘要：环境特征是调控植物物候期的核心触发与调控因子之一，生境丧失与破碎化驱动的非生物与生物变化，可导致植物物候格局发生改变。本研究旨在探究森林边缘与林内的树木群落物候格局是否存在差异。我们于两年内按月跟踪监测了7处人为干扰森林破碎化片段中树木群落的生殖物候动态，每个片段均设置200平方米的边缘样地与林内样地各1个。本研究共调查了0.28公顷的人为干扰森林破碎化片段，涵盖隶属于34科103种的313株树木（其中边缘样地180株，林内样地133株）。研究结果证实，森林边缘与林内树木群落的生殖物候存在显著差异，具体表现为：(1) 所有树木群落的物候活动在两种生境（森林边缘与林内）中均存在时间维度上的分化；(2) 对两种生境共有的树木物种而言，森林边缘的物候强度显著高于林内；(3) 仅统计各生境特有的物种时，2010年森林边缘出现物候活动的树木物种数更多，而2011年林内出现物候活动的物种数更多。综上，生境破碎化通过形成边缘带改变微环境特征，并进而影响包括树木生殖物候在内的各类生物过程。