Ecological values (EV) are defined by Cordell et al. (2005)[1] as “the level of benefits that biotic or abiotic components provide for the maintenance of any living organisms”, except humans. In turn, besides ecosystem services related to humans, Ratcliffe (1997)[2] provided a list of criteria to assign EV to an entity, considering different aspects: its size (extent), diversity, naturalness, rarity, fragility, typicalness, recorded history, position within an ecological/geographical unit and potential value. As these criteria remain loosely defined, EV used for vulnerability assessment to wildfires or to other disturbances are largely heterogeneous in the literature.
Among others, a commonly assessed EV is biodiversity through species richness and abundance or rarity and typicalness, as a major driver of ecosystem productivity [3] or aesthetic value [4]. Biodiversity includes all the variability of life (organisms, species, populations), their complex interactions and assemblages of communities and ecosystems. There are different scales and measures of biodiversity, including genetic diversity (that may be measured both at intraspecific or interspecific levels), species diversity (variation within and between populations or communities, different measures such as taxonomic, functional, or phylogenetic diversity) and ecosystem diversity (variation within and between ecosystems in habitats, communities and ecological processes). At the landscape level, a major EV relies on habitat fragmentation (size and shape from landscape metrics) and connectivity (corridor and distance between patches). Habitats relate to the benefit that nature provides to sustain life, including vegetation biomass and structure allowing animal foraging (food resource), movement (connectivity) and nesting (protection). Additional EV can be attributed to habitat naturalness, which refers to an ‘index describing how close a landscape is to a natural state’ [5] or how intact the habitat is from human impact or disturbances [6]. The conservation value depicts the human view and investment in conserving these intrinsic EV, and relies on legal protection using regional, national or international standards [7]. EV then include the structural assemblage of plants and animals, their associated biogeochemical stocks and cycles (carbon, water, nutrient), and the soil status (fertility based on nutrient content and available water content) required to maintain ecosystem functioning.
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Cordell, H.K., Murphy, D., Riitters, K.H., & Harvard, J. (2005). The natural ecological value of wilderness. In H.K. Cordell, J.C. Bergstrom, & J.M. Bowker (Eds.), The Natural Ecological Value of Wilderness (pp. 205-249). Alberta, Canada: Venture Publishing Inc. ↩︎
Ratcliffe, D. (1997). A nature conservation review: volume 1: the selection of biological sites of national importance to nature conservation in Britain. Cambridge: Cambridge University Press. ↩︎
Tilman, D., Isbell, F., & Cowles, J.M. (2014). Biodiversity and ecosystem functioning. Annual review of ecology, evolution, and systematics, 45, 471-493. ↩︎
Tribot, A.-S., Deter, J., & Mouquet, N. (2018). Integrating the aesthetic value of landscapes and biological diversity. Proceedings of the Royal Society B: Biological Sciences, 285, 20180971. ↩︎
Fry, G., Tveit, M.S., Ode, Å., & Velarde, M. (2009). The ecology of visual landscapes: Exploring the conceptual common ground of visual and ecological landscape indicators. Ecological indicators, 9, 933-947. ↩︎
Watson, J.E., Evans, T., Venter, O., Williams, B., Tulloch, A., Stewart, C., Thompson, I., Ray, J.C., Murray, K., & Salazar, A. (2018). The exceptional value of intact forest ecosystems. Nature ecology & evolution, 2, 599-610. ↩︎
Kangas, K.M., Tolvanen, A., Tarvainen, O., Nikula, A., Nivala, V., Huhta, E., & Jäkäläniemi, A. (2016). A method for assessing ecological values to reconcile multiple land use needs. Ecology and Society, 21 ↩︎