Global mapping of ecosystem services and conservation priorities

Abstract

Global efforts to conserve biodiversity have the potential to deliver economic benefits to people (i.e., "ecosystem services"). However, regions for which conservation benefits both biodiversity and ecosystem services cannot be identified unless ecosystem services can be quantified and valued and their areas of production mapped. Here we review the theory, data, and analyses needed to produce such maps and find that data availability allows us to quantify imperfect global proxies for only four ecosystem services. Using this incomplete set as an illustration, we compare ecosystem service maps with the global distributions of conventional targets for biodiversity conservation. Our preliminary results show that regions selected to maximize biodiversity provide no more ecosystem services than regions chosen randomly. Furthermore, spatial concordance among different services, and between ecosystem services and established conservation priorities, varies widely. Despite this lack of general concordance, "win-win" areas-regions important for both ecosystem services and biodiversity-can be usefully identified, both among ecoregions and at finer scales within them. An ambitious interdisciplinary research effort is needed to move beyond these preliminary and illustrative analyses to fully assess synergies and trade-offs in conserving biodiversity and ecosystem services.

Fig. 1.

Percentage accumulation of species (A) and ecosystem services (B) as total area selected for conservation increases. Circles represent optimizations of species representation (mean results from separate optimizations of birds, mammals, reptiles, and amphibians; error bars = 1 SD). Triangles represent optimizations of ecosystem services (mean results from separate optimizations of each of the four ecosystem services we considered). Shaded areas indicate 95% confidence limits from 500 sets of ecoregions selected at random. Dashed vertical lines indicate area at which all vertebrate species are represented.

Fig. 2.

Mean amount of ecosystem services per unit area provided by three global conservation priority schemes. (A) Carbon sequestration. (B) Carbon storage. (C) Grassland production of livestock. (D) Water provision. Horizontal lines represent the global mean for each service.

Fig. 3.

Relationship between ecosystem service importance and conservation importance. Each axis is the rank order (low to high) of 574 terrestrial ecoregions in terms of per-area carbon storage (y axis) or area-corrected number of endemic species [x axis; calculated as (No. endemic species/area^0.25)]. Lines indicate median values for each variable. Diamond in quadrant 4 represents the California Central Coast ecoregion.