Epiphytic lichen biomass in managed and old-growth boreal forests: Effect of branch quality
Epiphytic lichen biomass in managed and old-growth boreal forests: Effect of branch quality
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DOI：
10.2307/2269566
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发表时间：
1996-02-01
影响因子：
5
通讯作者：
Petersson, RB
中科院分区：
文献类型：
--
作者：
Esseen, PA;Renhorn, KE;Petersson, RB
为了维持管理森林的生物多样性，我们必须了解在未受干扰的生态系统中调节物种发生和动态的模式和过程。本研究比较了瑞典北部3对挪威云杉（Picea abies）原生林和选择性砍伐林分（每林分30支）180个下层枝上的地衣生物量和物种组成。目的是评价基质质量（枝型特征）对两种不同生长形式（叶型和果型）地衣生物量格局的影响。原生林的每枝地衣质量是人工林成熟林分的6倍，枝条质量百分比是成熟林分的2倍。地衣质量与枝条质量、直径和树龄密切相关。果状、下垂种（Alectoria sarmentosa和Bryoria spp）对森林活动高度敏感。相反，森林类型对叶类种类的影响不显著。两种林分的每林分种数相同（15种），但不同地衣类群的相对丰度存在显著差异。结果表明，地衣可利用的底物（即小枝）数量有限，且幼嫩枝为地衣定植和生长提供的时间较短，是限制林内附生地衣丰度的重要因素。将原生林转变为有管理的幼林将导致附生地衣质量的显著减少。这反过来可能会影响森林中的营养循环，并对利用冠层地衣作为食物、住所或筑巢材料的动物产生负面影响。
To maintain biodiversity in managed forests we must understand the patterns and processes that regulate the occurrence and dynamics of species in undisturbed ecosystems. We compared biomass and species composition of canopy lichens on 180 lower branches of Norway spruce (Picea abies) in three pairs of old-growth and managed (selectively logged) stands in northern Sweden (30 branches per stand). The purpose was to evaluate the effect of substrate quality (branch characteristics) on patterns of lichen biomass for two different growth forms (foliose and fruticose).Old-growth stands had six times higher lichen mass per spruce branch, and two times higher expressed as percentage of branch mass, compared to mature stands of managed forest. Lichen mass was strongly related to mass, diameter, and age of branches. Fruticose, pendulous species (Alectoria sarmentosa and Bryoria spp.) were highly sensitive to forest practices. In contrast, type of forest had no significant effect on foliose species. Species number per stand was the same (15 species) in both types of forest, but there were marked differences in the relative abundance of different lichen groups. Results suggest that limited amount of substrate (i.e., small branches) available to lichens, and young branches, providing only a short time for lichen colonization and growth, are important factors limiting epiphytic lichen abundance in managed forests. Conversion of old-growth forest into young, managed stands will lead to a significant reduction in epiphytic lichen mass. This in turn may probably affect nutrient cycling in forests and has negative consequences for animals that utilize canopy lichens as food, shelter, or nesting material.