O'Brien Erin E, Gersani Mordechai, Brown Joel S
Biological Sciences, Ecology, Evolution & Marine Biology, University of California, Santa Barbara, 93106, USA.
New Phytol. 2005 Nov;168(2):401-12. doi: 10.1111/j.1469-8137.2005.01520.x.
Here, we tested the predictions of a 'tragedy of the commons' model of below-ground plant competition in annual plants that experience spatial heterogeneity in their competitive environment. Under interplant competition, the model predicts that a plant should over-proliferate roots relative to what would maximize the collective yield of the plants. We predict that a plant will tailor its root proliferation to local patch conditions, restraining root production when alone and over-proliferating in the presence of other plants. A series of experiments were conducted using pairs of pea (Pisum sativum) plants occupying two or three pots in which the presence or absence of interplant root competition was varied while nutrient availability per plant was held constant. In two-pot experiments, competing plants produced more root mass and less pod mass per individual than plants grown in isolation. In three-pot experiments, peas modulated this response to conditions at the scale of individual pots. Root proliferation in the shared pot was higher compared with the exclusively occupied pot. Plants appear to display sophisticated nutrient foraging with outcomes that permit insights into interplant competition.
在此，我们对一年生植物地下部分植物竞争的“公地悲剧”模型的预测进行了测试，这些一年生植物在其竞争环境中经历空间异质性。在植物间竞争的情况下，该模型预测，相对于使植物集体产量最大化的情况，植物应该过度增殖根系。我们预测，植物会根据当地斑块条件调整其根系增殖，单独生长时抑制根系生长，而在有其他植物存在时过度增殖。我们使用成对的豌豆（Pisum sativum）植株进行了一系列实验，这些植株占据两盆或三盆，其中植物间根系竞争的有无是变化的，而每株植物的养分可利用量保持恒定。在两盆实验中，与单独生长的植物相比，竞争植物单株产生的根质量更大，豆荚质量更小。在三盆实验中，豌豆根据单个花盆的条件调节这种反应。与单独占据的花盆相比，共享花盆中的根系增殖更高。植物似乎表现出复杂的养分觅食行为，其结果有助于深入了解植物间竞争。
