Optimal root proliferation strategies: the roles of nutrient heterogeneity, competition and mycorrhizal networks
Optimal root proliferation strategies: the roles of nutrient heterogeneity, competition and mycorrhizal networks
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DOI：
10.1007/s11104-011-0943-3
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发表时间：
2012-02-01
期刊：
影响因子：
4.9
通讯作者：
Pitchford, Jonathan W.
中科院分区：
文献类型：
--
作者：
Croft, Simon Antony;Hodge, Angela;Pitchford, Jonathan W.
背景和目标植物通过繁殖根系来获取养分，通常会与异质资源和竞争性邻居进行竞争。开发了一个数学模型来确定斑块营养环境中的最佳根系增殖策略。还评估了加入菌根网络的影响。方法在遗传算法中建立一个空间维度上的生长和竞争的简单模型，以获得在不同资源分布情况下、在存在或不存在局部竞争和大规模菌根网络的情况下的最佳增殖策略。结果在低资源异质环境中的孤立植物以及在竞争中生长的植物都出现了强烈的增殖反应。即使在统计上均质的环境中，竞争的存在也会赋予植物向最近获得的斑块方向增殖的选择性优势。在存在菌根网络的情况下，随着通过网络获取资源的相对成本增加，最优策略从共生转向增殖驱动增长。是否存在竞争；以及通过与菌根的共生关系获取资源的边际效益。
Background and Aims Plants proliferate roots in order to acquire nutrients, typically contending with heterogeneous resources and competing neighbours. A mathematical model was developed to identify optimal root proliferation strategies in patchy nutrient environments. The impact of joining mycorrhizal networks was also assessed. Methods A simple model of growth and competition in one spatial dimension was implemented within a genetic algorithm to obtain optimal proliferation strategies under different scenarios of resource distribution, and in the presence or absence of local competition and large-scale mycorrhizal networks.Results A strong proliferation response emerged for isolated plants in heterogeneous environments with low resources, and also for plants growing in competition. Even in statistically homogeneous environments, the presence of competition conferred a selective advantage to plants proliferating in the direction of the most recently acquired patch. In the presence of mycorrhizal networks, the optimal strategy switched from symbiosis to proliferation driven growth as the relative cost of acquiring resources through the networks increased.Conclusions The optimal proliferation response in a given scenario was governed by a hierarchy of factors: resource levels and distribution; the presence or absence of competition; and the marginal benefit of obtaining resources via symbiotic relationships with mycorrhizas.