Canadian Forest Service, Pacific Forestry Centre, Natural Resources Canada, 506 West Burnside Road, Victoria, BC V8Z 1M5, Canada.
Environ Monit Assess. 2013 Apr;185(4):3057-79. doi: 10.1007/s10661-012-2773-z. Epub 2012 Jul 27.
Ecosystem classifications map an area into relatively homogenous units for environmental research, monitoring, and management. However, their effectiveness is rarely tested. Here, three classifications are (1) defined and characterized for Canada along summertime productivity (moderate-resolution imaging spectrometer fraction of absorbed photosynthetically active radiation) and wintertime snow conditions (special sensor microwave/imager snow water equivalent), independently and in combination, and (2) comparatively evaluated to determine the ability of each classification to represent the spatial and environmental patterns of alternative schemes, including the Canadian ecozone framework. All classifications depicted similar patterns across Canada, but detailed class distributions differed. Class spatial characteristics varied with environmental conditions within classifications, but were comparable between classifications. There was moderate correspondence between classifications. The strongest association was between productivity classes and ecozones. The classification along both productivity and snow balanced these two sets of variables, yielding intermediate levels of association in all pairwise comparisons. Despite relatively low spatial agreement between classifications, they successfully captured patterns of the environmental conditions underlying alternate schemes (e.g., snow classes explained variation in productivity and vice versa). The performance of ecosystem classifications and the relevance of their input variables depend on the environmental patterns and processes used for applications and evaluation. Productivity or snow regimes, as constructed here, may be desirable when summarizing patterns controlled by summer- or wintertime conditions, respectively, or of climate change responses. General purpose ecosystem classifications should include both sets of drivers. Classifications should be carefully, quantitatively, and comparatively evaluated relative to a particular application prior to their implementation as monitoring and assessment frameworks.
生态系统分类将一个区域划分为相对同质的单元，用于环境研究、监测和管理。然而，它们的有效性很少得到检验。在这里，根据夏季生产力（中等分辨率成像光谱仪吸收的光合有效辐射分数）和冬季雪况（专用传感器微波/成象仪雪水当量），独立和组合定义和描述了三种加拿大分类法，并对其进行了比较评估，以确定每种分类法在代表替代方案（包括加拿大生态区框架）的空间和环境模式方面的能力。所有分类法都在加拿大描绘了相似的模式，但详细的分类分布有所不同。分类的空间特征随分类内的环境条件而变化，但在分类之间具有可比性。分类之间存在中等程度的一致性。生产力分类与生态区之间的相关性最强。沿生产力和雪的分类平衡了这两组变量，在所有两两比较中产生了中等水平的相关性。尽管分类之间的空间一致性相对较低，但它们成功地捕获了替代方案的环境条件模式（例如，雪类解释了生产力的变化，反之亦然）。生态系统分类的性能及其输入变量的相关性取决于应用和评估中使用的环境模式和过程。如这里构建的生产力或雪况分类法，在分别总结夏季或冬季条件控制的模式或气候变化响应时可能是可取的。通用生态系统分类法应同时包含这两组驱动因素。在实施作为监测和评估框架之前，应根据特定应用对分类法进行仔细、定量和比较评估。
