Department of Biology, Syracuse University, Syracuse, NY 13210, USA.
Biology Department, University of Massachusetts Boston, Boston, MA 02125, USA.
Science. 2020 Oct 16;370(6514):346-350. doi: 10.1126/science.abb6703.
Mutualisms, or reciprocally beneficial interspecific interactions, constitute the foundation of many ecological communities and agricultural systems. Mutualisms come in different forms, from pairwise interactions to extremely diverse communities, and they are continually challenged with exploitation by nonmutualistic community members (exploiters). Thus, understanding how mutualisms persist remains an essential question in ecology. Theory suggests that high species richness and functional redundancy could promote mutualism persistence in complex mutualistic communities. Using a yeast system (), we experimentally show that communities with the greatest mutualist richness and functional redundancy are nearly two times more likely to survive exploitation than are simple communities. Persistence increased because diverse communities were better able to mitigate the negative effects of competition with exploiters. Thus, large mutualistic networks may be inherently buffered from exploitation.
互利共生关系，或者说互惠互利的种间相互作用，是许多生态群落和农业系统的基础。互利共生关系有不同的形式，从成对的相互作用到极其多样化的群落，它们不断受到非互利共生群落成员（剥削者）的剥削。因此，了解互利共生关系如何持续存在仍然是生态学中的一个基本问题。理论表明，高物种丰富度和功能冗余可以促进复杂互利共生群落中互利共生关系的持续存在。我们利用酵母系统（）进行了实验，结果表明，与简单群落相比，具有最多互利共生丰富度和功能冗余的群落，其在面临剥削时，能够维持下去的可能性几乎高出两倍。之所以能够持续存在，是因为多样化的群落能够更好地减轻与剥削者竞争的负面影响。因此，大型互利共生网络可能天生就具有抵御剥削的能力。
