Characterising spatial and temporal variation in the finite rate of population increase across the northern range boundary of the annual grass Vulpia fasciculata
Characterising spatial and temporal variation in the finite rate of population increase across the northern range boundary of the annual grass Vulpia fasciculata
复制标题
表征一年生禾草 Vulpia fasciculata 北部范围边界的有限人口增长率的时空变化
DOI：
10.1007/s00442-005-0102-8
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发表时间：
2005
期刊：
影响因子：
2.7
通讯作者：
A. Watkinson
中科院分区：
文献类型：
--
作者：
L. Norton;L. Firbank;A. Scott;A. Watkinson
面对环境变化，了解影响植物分布的因素对于生态学家来说是一个巨大的挑战。在这里，我们量化了一年生禾草 Vulpia fasciculata 种群有限增长率的空间和时间变化。具体来说，我们测试了以下假设：北部山脉边界与小于 1 的有限人口增长率相关。每年 4 年，一年生禾本科 V. fasciculata 的三种生态型的种子都会被引入英国的一系列地点，包括其当前范围边界以内 (11) 和以北 (4)。由于干扰，17% 的目标地点种群未能定居。在其余目标地点，人口有限增长率 λ 在 0.06 至 33.3 之间变化，几何平均值为 1.88。在人口增长率的总方差中，地点和年份效应独立地占变异的 40%，交互作用则占 50%；生态型占变异的不到5%。地点和年份之间的天气变化对植物的表现影响不大，并且没有迹象表明当前范围边界以北的种群增长率较低。我们得出的结论是，英国海岸当前的气候条件并未限制 V. fasciculata 的分布，并且来自其当前分布范围的种子具有大致相同的定植潜力。
Understanding the factors that influence plant distributions is a considerable challenge for ecologists in the face of environmental change. Here, we quantify spatial and temporal variation in the finite rate of population increase of the annual grass Vulpia fasciculata. Specifically, we test the hypothesis that the northern range boundary is associated with finite rates of population increase of less than one. Seeds of three ecotypes of the annual grass V. fasciculata were introduced annually across a range of sites in Great Britain both within (11) and to the north (4) of its current range boundary in each of 4 years. Populations failed to establish at 17% of target sites due to disturbance. At the remaining target sites, the finite rate of population increase, λ, varied from 0.06 to 33.3 with a geometric mean of 1.88. Of the total variance in the rate of population growth, site and year effects accounted independently for 40% of the variation and in interaction for 50%; ecotype accounted for less than 5% of the variation. Variation in the weather between sites and years had little impact on plant performance, and there was no indication that the rate of population growth was lower to the north of the current range boundary. We conclude that current climatic conditions on the coast of Great Britain are not limiting the distribution of V. fasciculata and that seeds from across its current range have roughly equivalent colonising potential.