Climate and interrelated tree regeneration drivers in mixed temperate–boreal forests
Climate and interrelated tree regeneration drivers in mixed temperate–boreal forests
复制标题
温带-寒带混交林的气候和相关的树木再生驱动因素
DOI：
10.1007/s10980-012-9827-z
复制
发表时间：
2012
影响因子：
5.2
通讯作者：
P. Reich
中科院分区：
文献类型：
--
作者：
N. Fisichelli;L. Frelich;P. Reich
森林组成的变化，气候变化的反应很可能是最初检测到的林下树木更新层附近的物种范围的限制。由于许多因素，除了气候，如苗床和土壤特性，上层组成，并与其他林下生物区系的相互作用，驱动树木更新的趋势，一个彻底的了解所有变量的相对重要性，以及它们之间的相互关系是必要的。几个广泛的温带和北方树种的范围限制重叠在上五大湖地区，美国，从而促进了相对较短的区域气候梯度的观测研究。我们使用冗余分析和变异划分来量化四组解释变量的唯一性、共享性和总解释力。结果表明，所有四个变量集（气候9.5%，林下环境13.7%，上层组成26.3%，林下生物群13.8%）与树木更新组成的变化在温带-北方混合森林显着相关。分区还显示了高混杂或共享的解释力，但也是每个集贡献了显着的独特的解释力不与其他集共享。再生组成的空间格局与大尺度环境格局密切相关，而大多数无法解释的变化没有可检测的空间结构，这表明局部尺度变异的因素。未来森林在整个景观中的变化不仅取决于气候变化的速度和方向，而且还取决于其他解释变量（如上层林组成和下层林生物群）之间的强度和相互关系如何随着气候变化而变化。
Forest compositional shifts in response to climate change are likely to be initially detectable in the understory tree regeneration layer near species range limits. Because many factors in addition to climate, such as seedbed and soil characteristics, overstory composition, and interactions with other understory biota, drive tree regeneration trends, a thorough understanding of the relative importance of all variables as well as their interrelationships is needed. The range limits of several widespread temperate and boreal tree species overlap in the upper Great Lakes region, USA, thus facilitating an observational study over relatively short regional climate gradients. We used redundancy analysis and variation partitioning to quantify the unique, shared, and total explanatory power of four sets of explanatory variables. The results showed that all four variable sets (climate 9.5 %, understory environment 13.7 %, overstory composition 26.3 %, and understory biota 13.8 %) were significantly associated with tree regeneration compositional variation in mixed temperate–boreal forests. Partitioning also revealed high confounded or shared explanatory power, but also that each set contributed significant unique explanatory power not shared with other sets. Spatial patterning in regeneration composition was strongly related to broad scale environmental patterns, while the large majority of unexplained variation did not have a detectable spatial structure, suggesting factors with local scale variability. Future forest shifts across the landscape will depend not only on the rate and direction of climate change but also on how the strengths and interrelationships among other explanatory variables, such as overstory composition and understory biota, shift with a changing climate.