Testing the importance of a common ectomycorrhizal network for dipterocarp seedling growth and survival in tropical forests of Borneo
Testing the importance of a common ectomycorrhizal network for dipterocarp seedling growth and survival in tropical forests of Borneo
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DOI：
10.1080/17550874.2017.1283649
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发表时间：
2016-01-01
影响因子：
1.5
通讯作者：
Egli, Simon
中科院分区：
文献类型：
--
作者：
Brearley, Francis Q.;Saner, Philippe;Egli, Simon
背景资料：在东南亚以龙脑香为主的热带雨林中，成熟树木和幼苗之间通过外生菌根（EcM）菌丝网络的连接可能对幼苗的生长和存活以及维持这种森林中的高多样性具有重要意义。我们进行了四个独立的实验，通过使用一系列的细网和/或塑料屏障，防止接触的实验幼苗与ECM网络。我们测量的生长和生存（和叶片三角洲C-13在一个实验）的幼苗6 dipterocarp物种的间隔范围从11到29 months.Results：幼苗生长（直径，高度或叶数）是不受影响的排除从EcM网络在三个实验中，并没有差异，在第四叶d13 C值。在一个实验中，幼苗存活率在被排除在EcM网络之外后降低。我们的研究结果几乎不支持这一假设，即龙脑香幼苗生长在阴凉的森林下层受益于被连接，通过一个共同的外膜网络，周围的树木。我们认为，与在低多样性的温带或热带森林中进行的研究相比，是由于这些高多样性的森林缺乏宿主物种特异性的EcM真菌，因此通过菌丝网络提供适应性支持幼苗的机会很少。
Background: Connections between mature trees and seedlings via ectomycorrhizal (EcM) hyphal networks existing in dipterocarp-dominated tropical rain forests of South- east Asia could have strong implications for seedling growth and survival and the maintenance of high diversity in such forests.Aim: To test whether EcM hyphal network connections are important for the growth and survival of dipterocarp seedlings.Methods: We conducted four independent experiments that prevented contact of experimental seedlings with an EcM network by using a series of fine meshes and/ or plastic barriers. We measured the growth and survival (and foliar delta C-13 in one experiment) of seedlings of six dipterocarp species over intervals ranging from 11 to 29 months.Results: Seedling growth (diameter, height or leaf number) was unaffected by exclusion from the EcM network in three experiments and there were no differences in foliar d13C values in the fourth. Seedling survival was reduced following exclusion from the EcM network in one experiment. Our results give little support to the hypothesis that dipterocarp seedlings growing in the shaded forest understorey benefit from being connected, through a common EcM network, to surrounding trees.Conclusions: We suggest that our negative results, in contrast to studies conducted in low diversity boreo- temperate or tropical forests, are due to these high diversity forests lacking host species-specific EcM fungi and therefore providing little opportunity for adaptive support of seedlings via hyphal networks.