Tree diversity increases robustness of multi-trophic interactions

Multi-trophic interactions maintain critical ecosystem functions. Biodiversity is declining globally, while responses of trophic interactions to biodiversity change are largely unclear. Thus, studying responses of multi-trophic interaction robustness to biodiversity change is crucial for understanding ecosystem functioning and persistence. We investigate plant-Hemiptera- (antagonism) and Hemiptera-ant- (mutualism) interaction networks in response to experimental manipulation of tree diversity. We show increased diversity at both higher trophic levels (Hemiptera and ants) and increased robustness through redundancy of lower level species of multi-trophic interactions when tree diversity increased. Hemiptera and ant diversity increased with tree diversity through non-additive diversity effects. Network analyses identified that tree diversity also increased the number of tree and Hemiptera species utilized by Hemiptera and ant species, and decreased the specialization on lower trophic leve...多营养级互作维系着关键的生态系统功能。当前全球范围内生物多样性持续下降，而营养级互作对生物多样性变化的响应在很大程度上仍不明朗。因此，探究多营养级互作鲁棒性对生物多样性变化的响应，对于理解生态系统的功能与存续至关重要。本研究针对实验操控树木多样性的场景，探究了植物-半翅目（Hemiptera，拮抗作用）与半翅目-蚂蚁（互利共生）两类互作网络。研究结果显示：当树木多样性提升时，更高营养级（半翅目昆虫与蚂蚁）的物种多样性显著增加，同时多营养级互作可通过低营养级物种的冗余性提升系统鲁棒性。半翅目昆虫与蚂蚁的物种多样性随树木多样性提升而增加，该现象由非加性多样性效应介导。网络分析结果表明：树木多样性同时提升了半翅目与蚂蚁物种所利用的树木及半翅目物种数量，并降低了对低营养级的特化程度……