Understanding patterns and processes in models of trophic cascades.
Understanding patterns and processes in models of trophic cascades.
复制标题
DOI：
10.1111/ele.12200
复制
发表时间：
2014-01
期刊：
影响因子：
8.8
通讯作者：
Steele JH
中科院分区：
文献类型：
--
作者：
Heath MR;Speirs DC;Steele JH
气候波动和人类开发正在造成陆地和水生生态系统营养物富集的全球变化以及顶端捕食者丰度的下降。由此产生的营养级联对食物网产生了深远的影响，导致了重大的经济和社会后果。然而，级联效应的强度——即扰动在食物网中传播时减弱的程度——在不同的生态系统之间差异很大，并且没有正式的理论来解释为什么会这样。一些食物链模型再现了自然界中看到的级联效应，但这在多大程度上取决于它们的配方？我们表明，在简单的食物链模型中，要生成现实的“自上而下”级联，必须包含在数学上表示为消费者摄取或死亡率的密度依赖调节的过程。实际模拟的由营养输入变化引起的“自下而上”级联也依赖于纳入密度依赖，但尤其依赖于死亡率调节，例如疾病和寄生虫动态或野生动物捕食。我们表明，我们的结论，基于简单的食物链，转移到一个更复杂的海洋食物网模型，其中级联是由不同的河流营养输入或鱼类收获率引起的。
Climate fluctuations and human exploitation are causing global changes in nutrient enrichment of terrestrial and aquatic ecosystems and declining abundances of apex predators. The resulting trophic cascades have had profound effects on food webs, leading to significant economic and societal consequences. However, the strength of cascades–that is the extent to which a disturbance is diminished as it propagates through a food web–varies widely between ecosystems, and there is no formal theory as to why this should be so. Some food chain models reproduce cascade effects seen in nature, but to what extent is this dependent on their formulation? We show that inclusion of processes represented mathematically as density-dependent regulation of either consumer uptake or mortality rates is necessary for the generation of realistic ‘top-down’ cascades in simple food chain models. Realistically modelled ‘bottom-up’ cascades, caused by changing nutrient input, are also dependent on the inclusion of density dependence, but especially on mortality regulation as a caricature of, e.g. disease and parasite dynamics or intraguild predation. We show that our conclusions, based on simple food chains, transfer to a more complex marine food web model in which cascades are induced by varying river nutrient inputs or fish harvesting rates.
登录
查看更多内容
DOI：
10.1098/rspb.2009.1512
发表时间：
2010-03-07
影响因子：
4.7
作者：
Andersen, K. H.;Pedersen, M.
通讯作者：
Pedersen, M.
影响因子：
64.8
作者：
Frank, Kenneth T.;Petrie, Brian;Leggett, William C.
通讯作者：
Leggett, William C.
DOI：
10.1098/rspb.2007.1752
发表时间：
2008-08-07
影响因子：
4.7
作者：
Casini, Michele;Lovgren, Johan;Kornilovs, Georgs
通讯作者：
Kornilovs, Georgs
影响因子：
3.1
作者：
Christensen, V;Walters, CJ
通讯作者：
Walters, CJ
影响因子：
3.7
作者：
Attayde, Jose Luiz;Ripa, Joergen
通讯作者：
Ripa, Joergen