Competitive effect is a linear function of neighbour biomass in experimental populations of Kochia scoparia
Competitive effect is a linear function of neighbour biomass in experimental populations of Kochia scoparia
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DOI：
10.1111/j.1365-2745.2005.01082.x
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发表时间：
2006-03
影响因子：
5.5
通讯作者：
D. Ramseier;J. Weiner
中科院分区：
文献类型：
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作者：
D. Ramseier;J. Weiner
1在植物个体水平上的生长和竞争研究中，邻体大小和距离是混淆的。为了研究邻体大小对竞争效应的影响，我们将目标地肤个体生长在六个等距的、年龄均匀的同种邻体周围。我们通过在不同时间播种相邻植物来改变相邻植物的大小，并且我们还改变目标植物的播种时间，以在竞争过程中产生相邻植物和目标植物大小的变化。我们分析了目标植物在两个时间间隔内的生长，作为其自身大小和其邻居在间隔开始时的大小的函数。2.当竞争变得激烈时，目标植物的相对生长速率主要取决于其邻居的大小。目标植物的相对生长速率在一个时间段内与其相邻植物的生物量在该时间段开始时呈负线性关系。目标植物本身的大小对预测其生长速率没有显著的额外贡献。种群（目标+邻居）生物量的增长是有限度的，个体的增长是在这一限制范围内发生的。局部生物量密度主要由邻近的个体决定，对个体的生长可能比个体本身的大小重要得多。[3]没有证据表明存在规模不对称竞争。邻居的大小是目标植物的相对生长率的主要决定因素，但一定数量的邻居生物量的效果是相同的邻居大于和那些小于目标植物。
1 Neighbour size and distance are confounded in most studies of plant growth and competition at the individual level. To investigate the effects of neighbour size on competitive effect, we grew target Kochia scoparia individuals surrounded by six equidistant, even‐aged conspecific neighbours. We varied neighbour size by sowing groups of neighbours at different times, and we also varied the sowing time of the target plants to generate variation in both neighbour and target size during the process of competition. We analysed the growth of target plants over two time intervals as a function of their own size and the size of their neighbours at the beginning of the interval. 2 When competition became intense, the relative growth rate of target plants was primarily determined by the size of their neighbours. There was a negative linear relationship between the relative growth rate of target plants over an interval and the biomass of their neighbours at the beginning of the interval. The size of the target plant itself did not make a significant additional contribution to predicting its growth rate. There is a limit on the growth in biomass of the population (target + neighbours), and growth of individuals occurs within this constraint. Local biomass density, which can be primarily determined by neighbouring individuals, can be much more important for an individual's growth than its own size. 3 There was no evidence of size‐asymmetric competition. The size of neighbours was the primary determinant of a target plant's relative growth rate, but the effect of a given amount of neighbour biomass was the same for neighbours larger and those smaller than the target plant.