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Submitted to: Evolutionary Applications
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/4/2013 Publication Date: 11/1/2013 Citation: Jones, T.A. 2013. When local isn't best. Evolutionary Applications. 6:1109-1118. Interpretive Summary: Local plant materials are often preferred for the practice of ecological restoration. This is often justified by the maxim "Local is best," but there are many situations in which performance of non-local plant materials may exceed that of local populations. Based on generally accepted ecological and evolutionary concepts, this paper contends that the assumption that local genotypes are sacrosanct is based on the overemphasis of certain principles at the expense of others, resulting in an unbalanced perspective. To be most effective, plant materials for restoration purposes should be chosen on their adaptation to current ecological site conditions, which may be greatly modified from their pristine state, and their ability to adapt to potential future conditions. These arguments can be used by restoration practitioners to justify their choices of plant materials using generally accepted ecological and evolutionary principles. Technical Abstract: Local plant materials are often preferred for the practice of ecological restoration, and this is likely related to the preference for pristine lands for study by the scientific community. While the 'local-is-best' plant material paradigm may be appropriate for pristine lands, it may not be directly applicable in the context of the seriously degraded lands commonly targeted for restoration. This paper explains how twelve ecological, evolutionary, and methodological concepts have been commonly misinterpreted or misapplied in making the assumption that local is best. Evolution does not necessarily lead to optimal local adaptation. Local genotypes are to a certain extent transient, being merely the effect, rather than the cause, of natural selection and past historical genetic patterns. This suggests that local genotypes have no inherent worth in an absolutist sense. Genotypes chosen for restoration are most likely to be effective if they are adapted to current site conditions, which in many cases differ dramatically from those present historically. Thus, the most effective genotypes for restoration are not necessarily local genotypes. For purposes of ecological restoration, local adaptation is often emphasized, while the importance of general adaptation across environments does not always receive the attention that it merits. This paradox is expected to exacerbate as environmental change accelerates, both globally and locally. For this rerson, 'local is best' is better thought of as a model working assumption that can be tested rather than as a sacrosanct doctrine. Local provenance is important for developing restoration plant materials to the extent that it is biologically relevant, but it is best not employed as an absolute rule in the real world of ecological restoration. This more circumspect role for provenance is reflected in recent conceptual development, such as the current definition of ecological restoration by the Society for Ecological Restoration International and the Restoration Gene Pool concept. |
