Providing food, timber, energy, housing, and other goods and services, while maintaining ecosystem functions and biodiversity that underpin their sustainable supply, is one of the great challenges of our time. Understanding the drivers of land-use change and how policies can alter land-use change will be critical to meeting this challenge. Here we project land-use change in the contiguous United States to 2051 under two plausible baseline trajectories of economic conditions to illustrate how differences in underlying market forces can have large impacts on land-use with cascading effects on ecosystem services and wildlife habitat. We project a large increase in croplands (28.2 million ha) under a scenario with high crop demand mirroring conditions starting in 2007, compared with a loss of cropland (11.2 million ha) mirroring conditions in the 1990s. Projected land-use changes result in increases in carbon storage, timber production, food production from increased yields, and >10% decreases in habitat for 25% of modeled species. We also analyze policy alternatives designed to encourage forest cover and natural landscapes and reduce urban expansion. Although these policy scenarios modify baseline land-use patterns, they do not reverse powerful underlying trends. Policy interventions need to be aggressive to significantly alter underlying land-use change trends and shift the trajectory of ecosystem service provision.econometric model | incentives | at-risk birds | game species | amphibians L and-use change can greatly alter the provision of ecosystem services. Globally, the conversion of native grasslands, forests, and wetlands into croplands, tree plantations, and developed areas has led to vast increases in production of food, timber, housing, and other commodities but at the cost of reductions in many ecosystem services and biodiversity (1). Although recent land-use change in the United States has not been as rapid as in the tropics, it has been significant. The area of croplands has decreased and forests and urban areas have expanded since World War II (2). For example, forest lands in the contiguous United States expanded by 5.7 million acres between 1982 and 2007. However, basic estimates of net land-use change often hide more complex dynamics. More than 30 million acres transitioned into or out of forest between 1982 and 2007 (3). Such transitions alter landscape patterns and ecosystem functions, both of which affect the provision of ecosystem services.We use an econometric model to predict spatially explicit landuse change across the contiguous United States from 2001 to 2051. The model estimates the probability of conversion among major land-use categories (cropland, pasture, forest, range, and urban) based on observations of past land-use change, characteristics of land parcels, and economic returns, while accounting for endogenous feedbacks from the policies into commodity prices. A key advantage of this approach is that it allows us to simulate the effects of future policies that modify the relative ret...
Five known species (aspevulus Quate & Fairchild, erehicolus Quate, pholetor Quate & Fairchild, sejunctus Quate, and stellae Quate) of the cavernicolous subgenus Phlebutomus (Zdiophlebotomus)are discussed in relation to newly recognized species from West Malaysia and India. P.frondifer n.sp. and P.tubijiev nsp. are described and a key to the adults of all seven species is given. General features of the subgenus are discussed, with particular reference to the functional relationships between the specialized morphology of the mouthparts and the probable bat hosts of these species.
We develop an integrated model to predict private land-use decisions in response to policy incentives designed to increase the provision of carbon sequestration and species conservation across heterogeneous landscapes. Using data from the Willamette Basin, Oregon, we compare the provision of carbon sequestration and species conservation under five simple policies that offer payments for conservation. We evaluate policy performance compared with the maximum feasible combinations of carbon sequestration and species conservation on the landscape for various conservation budgets. None of the conservation payment policies produce increases in carbon sequestration and species conservation that approach the maximum potential gains on the landscape. Our results show that policies aimed at increasing the provision of carbon sequestration do not necessarily increase species conservation and that highly targeted policies do not necessarily do as well as more general policies.conservation payments ͉ ecosystem services ͉ landscape modeling ͉ private landowners ͉ land-use change
Four new species are described and descriptions of many others revised, and 128 species and two subspecies are now known from the Region. Keys to females of Grassomyia and the Sergentomyia babu series are provided, and the S.arboris series is defined and shown to be an exceptional long-labrum group. Particulars of 1511 specimens from Indonesia are reported. The vector of kala-azar around Calcutta is shown to be one of four variants of Phlebotomus argenripes and to have, on average, a slightly longer labrum than the others, more suitable for mammal feeding. The labral length of P.argentipes is, surprisingly, somewhat intermediate between those of most reptile and mammal feeders. Study of both Oriental and other sandflies strongly suggests that in Old and New Worlds the labrum has lengthened in relation to mammal feeding. In the Old World this has been accompanied by advance of the labral main adoral sensilla to produce a morphological, and probably functional, difference between the main Leishmania-vector groups of the two hemispheres.
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