Saprotrophic cord-forming fungi: meeting the challenge of heterogeneous environments
Saprotrophic cord-forming fungi: meeting the challenge of heterogeneous environments
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DOI：
10.2307/3761190
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发表时间：
1999-01-01
期刊：
影响因子：
2.8
通讯作者：
Boddy, L
中科院分区：
文献类型：
--
作者：
Boddy, L
许多腐食性真菌，特别是担子菌，能够从它们为寻找新资源而定殖的基质中生长出来（即，非资源单位限制性真菌）形成菌丝索，其是主要平行的、纵向排列的菌丝的聚集体。这些索往往形成广泛的、长期存在的系统，将北方、温带和热带森林地面上分散的营养资源，如木质凋落物成分相互连接起来，有些索还能在热带林冠中形成网络。它们表现出不同物种的觅食策略，并根据资源的数量和质量，其他生物的存在和小气候环境而改变。它们形成的形态图案可以用分形几何学很好地描述。当菌丝体觅食过程中遇到新的资源或将新的资源添加到成熟系统中时，它们的菌丝体显示出生物量和矿物质营养的重新分配的显着模式。菌丝索系统遇到不均匀分布的有机基质协调使用可用的资源，使需求得到满足的“分散负荷”通过系统。持续的网络，觅食新资源的能力，以及重新分配菌丝生物量和营养物质的能力，腐食索形成真菌所表现出的空间和时间异质环境中的生活问题提供了一个解决方案。对这些真菌存在的异质性环境的响应在它们自身中产生异质性，并且它们反过来在它们的环境中产生异质性，在空间和时间上。
Many saprotrophic fungi, especially basidiomycetes, which are able to grow out of the substratum that they are colonizing in search of new resources (i.e., nonresource-unit-restricted fungi) form mycelial cords, which are aggregations of predominantly parallel, longitudinally aligned hyphae. These cords often form extensive, long-lived systems which interconnect discrete nutrient resources, e.g. woody litter components, on the floor of boreal, temperate and tropical forests, and some can form networks in tropical canopies. They exhibit foraging strategies which vary among species, and which alter depending on resource quantity and quality, the presence of other organisms, and microclimatic environment. The morphological patterns they form are well described by fractal geometry. Their mycelia show remarkable patterns of reallocation of biomass and mineral nutrients when new resources are encountered during mycelial foraging or when new resources are added to mature systems. Mycelial-cord systems encountering heterogeneously distributed organic substrata coordinate use of available resources so that demands are met by 'spreading the load' through the system. The persistent networks, ability to forage for new resources, and ability to reallocate mycelial biomass and nutrients exhibited by saprotrophic cord-forming fungi provide a solution to the problems of life in a spatially and temporally heterogenous environment. Response to the heterogenous environ ment in which these fungi exist generates heterogeneity in themselves, and they in turn generate heterogeneity in their environment, both in space and time.