title: Biodiversity influences plant productivity through niche-efficiency.
abstract: The loss of biodiversity is threatening ecosystem productivity and services worldwide, spurring efforts to quantify its effects on the functioning of natural ecosystems. Previous research has focused on the positive role of biodiversity on resource acquisition (i.e., niche complementarity), but a lack of study on resource utilization efficiency, a link between resource and productivity, has rendered it difficult to quantify the biodiversity-ecosystem functioning relationship. Here we demonstrate that biodiversity loss reduces plant productivity, other things held constant, through theory, empirical evidence, and simulations under gradually relaxed assumptions. We developed a theoretical model named niche-efficiency to integrate niche complementarity and a heretofore-ignored mechanism of diminishing marginal productivity in quantifying the effects of biodiversity loss on plant productivity. Based on niche-efficiency, we created a relative productivity metric and a productivity impact index (PII) to assist in biological conservation and resource management. Relative productivity provides a standardized measure of the influence of biodiversity on individual productivity, and PII is a functionally based taxonomic index to assess individual species' inherent value in maintaining current ecosystem productivity. Empirical evidence from the Alaska boreal forest suggests that every 1% reduction in overall plant diversity could render an average of 0.23% decline in individual tree productivity. Out of the 283 plant species of the region, we found that large woody plants generally have greater PII values than other species. This theoretical model would facilitate the integration of biological conservation in the international campaign against several pressing global issues involving energy use, climate change, and poverty.
authors.affiliation: School of Natural Resources, West Virginia University, Morgantown, WV 26506; alpenbering@gmail.com.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Liang
authors.affiliation: School of Natural Resources, West Virginia University, Morgantown, WV 26506;
authors.forename: Mo
authors.initials: M
authors.lastname: Zhou
authors.affiliation: Northern Research Station, Forest Service, US Department of Agriculture, Morgantown, WV 26505;
authors.forename: Patrick C
authors.initials: PC
authors.lastname: Tobin
authors.affiliation: US Geological Survey, Alaska Cooperative Fish and Wildlife Research Unit, University of Alaska Fairbanks, Fairbanks, AK 99775;
authors.forename: A David
authors.initials: AD
authors.lastname: McGuire
authors.affiliation: Department of Forest Resources, University of Minnesota, St. Paul, MN 55108; and Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, NSW 2751, Australia.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Reich
mesh_terms: D000413:Alaska; D044822:Biodiversity; D018533:Biomass; D057231:Climate Change; D003247:Conservation of Natural Resources; D065928:Forests; D008962:Models, Theoretical; D063245:Plant Development; D018521:Plant Physiological Phenomena; D010944:Plants / Q000145:classification*; D011203:Poverty; D013045:Species Specificity; D014197:Trees
keywords: biodiversity loss; biological conservation; marginal productivity; productivity impact index; relative productivity