Temperature, precipitation and biotic interactions as determinants of tree seedling recruitment across the tree line ecotone
Temperature, precipitation and biotic interactions as determinants of tree seedling recruitment across the tree line ecotone
复制标题
DOI：
10.1007/s00442-015-3360-0
复制
发表时间：
2015
期刊：
影响因子：
2.7
通讯作者：
Lise Tingstad;S. Olsen;K. Klanderud;V. Vandvik;M. Ohlson
中科院分区：
文献类型：
--
作者：
Lise Tingstad;S. Olsen;K. Klanderud;V. Vandvik;M. Ohlson
幼苗补充是树木生命史的关键阶段，成功的补充与非生物因素和生物相互作用密切相关。为了更好地了解树种的分布如何因预期的气候变化而变化，需要更多地了解复杂气候和生物相互作用的影响。我们进行了一项播种实验，以调查温度、降水和生物相互作用如何影响挪威南部赤松 (Pinus sylvestris) 和挪威云杉 (Picea abies) 幼苗的补充。将种子播种到完整的植被中，并通过实验创造出间隙。为了研究温度和降水的综合影响，该实验在 12 个地点进行了重复，涵盖了从北方到高山、从次大陆到海洋的自然气候梯度。分别在播种后 12 个月和 16 个月评估幼苗的出苗率和存活率，并在实验结束时测定地上生物量和高度。有趣的是，在北方地区检测到的幼苗很少，而在高山地区出现和定植的幼苗数量最多，这表明低温并没有限制幼苗的补充。场地降水对幼苗补充具有总体积极影响，特别是在中等降水水平下。在所有温度水平下，与完整植被相比，间隙地块中的幼苗出苗、建植和生物量均较高。这些结果表明，竞争形式的生物相互作用可能比温度更重要，作为挪威南部亚高山和低高山地区树木幼苗补充的限制因素。
Seedling recruitment is a critical life history stage for trees, and successful recruitment is tightly linked to both abiotic factors and biotic interactions. In order to better understand how tree species’ distributions may change in response to anticipated climate change, more knowledge of the effects of complex climate and biotic interactions is needed. We conducted a seed-sowing experiment to investigate how temperature, precipitation and biotic interactions impact recruitment of Scots pine (Pinus sylvestris)and Norway spruce (Picea abies)seedlings in southern Norway. Seeds were sown into intact vegetation and experimentally created gaps. To study the combined effects of temperature and precipitation, the experiment was replicated across 12 sites, spanning a natural climate gradient from boreal to alpine and from sub-continental to oceanic. Seedling emergence and survival were assessed 12 and 16 months after sowing, respectively, and above-ground biomass and height were determined at the end of the experiment. Interestingly, very few seedlings were detected in the boreal sites, and the highest number of seedlings emerged and established in the alpine sites, indicating that low temperature did not limit seedling recruitment. Site precipitation had an overall positive effect on seedling recruitment, especially at intermediate precipitation levels. Seedling emergence, establishment and biomass were higher in gap plots compared to intact vegetation at all temperature levels. These results suggest that biotic interactions in the form of competition may be more important than temperature as a limiting factor for tree seedling recruitment in the sub- and low-alpine zone of southern Norway.