Gossner Martin M, Brändle Martin, Brandl Roland, Bail Johannes, Müller Jörg, Opgenoorth Lars
Terrestrial Ecology Research Group, Department of Ecology and Ecosystem Management, Technische Universität München, Hans-Carl-von-Carlowitz-Platz 2, 85354 Freising, Germany.
University of Marburg, Department of Ecology, Karl-von-Frisch Strasse 8, D-35043 Marburg, Germany.
PLoS One. 2015 Jan 30;10(1):e0115733. doi: 10.1371/journal.pone.0115733. eCollection 2015.
Through a series of common garden experiments, it has been shown that heritable phenotypic differences between individual trees can affect arthropod communities. However, field studies under heterogeneous environmental conditions remain rare. In the present study, we investigated the genetic constitution of 121 mature oak host trees at different trophic levels from 10 sites across Bavaria, southern Germany and their associated insect communities. A total of 23,576 individuals representing 395 species of beetles and true bugs were evaluated. In particular, we determined whether the composition of arthropod communities is related to the oak genotype and whether the strength of the relationships decreases from lower to higher trophic levels, such as for phytophagous, xylophagous, zoophagous, and mycetophagous species. The genetic differentiation of oaks was assessed using eight microsatellite markers. We found no significant influence of the oak genotype on neither the full beetle and true bug community nor on any of the analyzed trophic guilds. In contrast, the community composition of the insects was highly related to the space and climate, such that the community similarity decreased with increases in spatial distance and climatic differences. The relationship with space and climate was much stronger in beetles than in true bugs, particularly in mycetophagous species. Our results suggest that spatial processes override the genetic effects of the host plant in structuring arthropod communities on oak trees. Because we used neutral markers, we cannot exclude the possibility that trait-specific markers may reveal a genetic imprint of the foundation tree species on the composition of the arthropod community. However, based on the strength of the spatial patterns in our data set, we assume that genetic differences among oaks are less important in the structuring of arthropod communities. Future whole-genome studies are required to draw a final conclusion.
通过一系列的共同园圃实验表明，单株树木之间可遗传的表型差异会影响节肢动物群落。然而，在异质环境条件下的实地研究仍然很少。在本研究中，我们调查了德国南部巴伐利亚州10个地点不同营养级的121棵成熟栎树寄主及其相关昆虫群落的遗传构成。共评估了代表395种甲虫和蝽象的23576个个体。具体而言，我们确定节肢动物群落的组成是否与栎树基因型有关，以及这种关系的强度是否从低营养级到高营养级逐渐减弱，例如植食性、蛀木性、肉食性和食菌性物种。使用8个微卫星标记评估栎树的遗传分化。我们发现栎树基因型对整个甲虫和蝽象群落以及任何分析的营养类群均无显著影响。相反，昆虫的群落组成与空间和气候高度相关，以至于群落相似度随着空间距离和气候差异的增加而降低。甲虫与空间和气候的关系比蝽象更强，尤其是在食菌性物种中。我们的结果表明，在构建栎树上的节肢动物群落时，空间过程超越了寄主植物的遗传效应。由于我们使用中立标记，我们不能排除特定性状标记可能揭示基础树种对节肢动物群落组成的遗传印记的可能性。然而，基于我们数据集中空间模式的强度，我们认为栎树之间的遗传差异在节肢动物群落构建中不太重要。未来需要进行全基因组研究才能得出最终结论。
