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首页> 外文期刊>Northern Journal of Applied Forestry >Environmental Drivers of Succession in Jack Pine Stands of Boreal Ontario: An Application of Survival Analysis
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Environmental Drivers of Succession in Jack Pine Stands of Boreal Ontario: An Application of Survival Analysis

机译：安大略北部杰克松林林分演替的环境驱动因素：生存分析的应用

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摘要

In this study, we present a quantitative approach to examining species compositional changes in jack pine [Pinus banksiana Lamb.)-dominated forests that combines photo chronosequencing and survival analysis. Study sites (178) were selected from Ontario's Growth and Yield Permanent Sample Plot network and supplemented with archived aerial photographs that captured stand conditions at four additional points in time. Environmental attributes specific to geographic location, topography, soil characteristics, and climate were also used in the analysis. The nonparametric Kaplan-Meier method was used to derive cumulative survival functions, and Cox regression analysis was used to determine the significant environmental factors that resulted in downward shifts in jack pine persistence over time. Only 26% of the stands included in this study were observed to have a pure jack pine canopy during some stage of stand development, with black spruce (Picea mariana [Mill.] B.S.P.) being the most common associate.Although shifts in species composition occurred in the majority of stands, much of the observed succession was a reflection of differential growth rates and responses to suppression between contemporaneously established populations. Based on the Cox regression model, sites with sloped terrain, sites that had deep sandy soils, and sites that received high precipitation during the growing season all retained high abundances of jack pine over time.
机译：在这项研究中，我们提出了一种定量方法，该方法结合了照片时间序列和生存分析，研究了以杰克松（Pinus bankiana Lamb。）为主的森林的物种组成变化。研究地点（178个）是从安大略省的“生长和产量永久性样本地块”网络中选择的，并补充了存档的航空照片，这些照片在另外四个时间点捕获了林分状况。分析中还使用了特定于地理位置，地形，土壤特征和气候的环境属性。非参数Kaplan-Meier方法用于导出累积生存函数，Cox回归分析用于确定导致千斤顶松树持久性随时间下降的重要环境因素。在该研究中仅观察到26％的林分在林分发育的某个阶段具有纯杰克松林冠层，其中最常见的是黑云杉（Picea mariana [Mill。] BSP）。尽管物种组成发生了变化在大多数看台上，观察到的演替大部分反映了不同的增长率以及同期种群之间对抑制的反应。基于Cox回归模型，地形倾斜的地点，具有深沙质土壤的地点以及在生长季节受到高降水的地点都随时间推移保留了高丰度的千斤顶松树。

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