Actual distribution of U.S. wealth in 1995.

<p>Solid line represents the best fit for the Pareto distribution () and the dashed curve represents the best fit from our model (). The -axis shows accumulated capital, log scale; the -axis shows the portion of the population having that amount of capital or more, log scale. Both are two-parameter curves.</p

Modeled wealth distribution.

<p>In simulations with , % and all 100,000 individuals starting with wealth of 1 at time zero, the lower portion of the wealth distribution is represented by the blue line at time , the red line at time , and the black line at time . Circles indicate the median wealth and diamonds indicate the mean wealth. Note that mean wealth increases much faster than median wealth, while in this case the modal wealth, identified by the peaks of the curves, decreases. Over time, an increasing portion of the population has wealth greater than 20 units (0.01% of the population, 1%, and 18% at , 12, and 31, respectively), which is not depicted because it falls beyond the right boundary of the graph.</p

Appendix A. A description of heuristic algorithms, species data, and landscape data.

A description of heuristic algorithms, species data, and landscape data

Examples of an optimal reserve design on the stylized landscape.

<p>Dark gray = species 1 present; light gray = species 2 present; black and white = biodiversity hotspot; reserve sites marked by bolded parcel outline. (a) Zero hotspot. (b) One hotspot. (c) Two adjacent hotspots. (d) Three hotspots.</p

Near-optimal reserve design for the Oregon landscape.

<p>Near-optimal reserve design for the Oregon landscape.</p

Five-by-five grid stylized landscape.

<p>Five-by-five grid stylized landscape.</p

Full Archive

Full Archiv

Present value of benefits and costs per acre (2010 $), return to investment, and the pay-back period.

<p>Present value of benefits and costs per acre (2010 $), return to investment, and the pay-back period.</p

Annual value of ecosystem services (thousands 2010 $) from post-1988 conservation for 1992, 2022, and 2052 for the baseline and the agricultural expansion LULC change scenarios.

<p>The present value of stream of annual ecosystem services for each LULC change scenario is calculated.</p>a<p>The per household value of a percent reduction in phosphorous is from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062202#pone.0062202-Mathews1" target="_blank">[45]</a> at the high end and from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062202#pone.0062202-Johnston1" target="_blank">[41]</a> at the low-end.</p

Evaluating the Return in Ecosystem Services from Investment in Public Land Acquisitions

<div><p>We evaluate the return on investment (ROI) from public land conservation in the state of Minnesota, USA. We use a spatially-explicit modeling tool, the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST), to estimate how changes in land use and land cover (LULC), including public land acquisitions for conservation, influence the joint provision and value of multiple ecosystem services. We calculate the ROI of a public conservation acquisition as the ratio of the present value of ecosystem services generated by the conservation to the cost of the conservation. For the land scenarios analyzed, carbon sequestration services generated the greatest benefits followed by water quality improvements and recreation opportunities. We found ROI values ranged from 0.21 to 5.28 depending on assumptions about future land use change, service values, and discount rate. Our study suggests conservation is a good investment as long as investments are targeted to areas with low land costs and high service values.</p></div