Worldwide, changing climates and land use practices are escalating woody-plants encroachment into grasslands, reducing biodiversity and altering ecosystem functions. The loss of alpine grasslands is a major conservation concern as they harbor many rare and endemic species. Alpine meadows in Northwest Yunnan, China, represent a global biodiversity hotspot with high species richness, beta diversity, and endemism. Shrubs have expanded greatly in the region and threaten alpine meadow biodiversity. To measure rates of meadow loss due to shrub encroachment and identify its mechanisms, we reconstructed alpine land cover, climate, and land use change from 1950 to 2009 across Northwest Yunnan using satellite data, ground surveys, and interviews. Between 1990 and 2009, at least 39% of the alpine meadows converted to woody shrubs. The patterns of change suggest that a regime shift is occurring. Despite multiple perturbations to the climate and land use systems starting in the 1950s, alpine meadows remained resilient to shrub expansion until the late 1980s. Shrublands rapidly expanded then due to feedback mechanisms involving climate, woody cover, and grazing. Fire may no longer be an effective tool for controlling shrub expansion. This regime shift threatens both endemic meadow biodiversity and local livelihoods. More generally, these trends serve as a warning sign for the greater Himalayan region where similar vegetation changes could greatly affect livelihoods, hydrology, and climate.
File: Brandt-et-al-BiolCons2013.pdf
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How to best site reserves is a leading question for conservation biologists. Recently, reserve selection has emphasized efficient conservation: maximizing conservation goals given the reality of limited conservation budgets, and this work indicates that land market can potentially undermine the conservation benefits of reserves by increasing property values and development probabilities near reserves. Here we propose a reserve selection methodology which optimizes conservation given both a budget constraint and land market feedbacks by using a combination of econometric models along with stochastic dynamic programming. We show that amenity based feedbacks can be accounted for in optimal reserve selection by choosing property price and land development models which exogenously estimate the effects of reserve establishment. In our empirical example, we use previously estimated models of land development and property prices to select parcels to maximize coarse woody debris along 16 lakes in Vilas County, WI, USA. Using each lake as an independent experiment, we find that including land market feedbacks in the reserve selection algorithm has only small effects on conservation efficacy. Likewise, we find that in our setting heuristic (minloss and maxgain) algorithms perform nearly as well as the optimal selection strategy. We emphasize that land market feedbacks can be included in optimal reserve selection; the extent to which this improves reserve placement will likely vary across landscapes.
File: Butsic_etal_2013_JEM.pdf
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The concept of naturalness was developed to assess to what degree landscapes represent a natural state. Protected areas are often regarded as the remnants of untouched landscapes although many landscapes commonly perceived as pristine have a long history of human impact. Here, we introduced a historical perspective into the concept of naturalness and the analysis of the effectiveness of protected areas by analyzing historical trajectories in land-cover and forest communities for the Pictured Rocks National Lakeshore on Michigan's Upper Peninsula (USA). Distribution of land-cover and forest community types was reconstructed for pre-settlement time (around 1850), the height of agricultural expansion (1928), and modern conditions (2000). Naturalness of the landscape was assessed by analyzing similarity between pre-settlement and current conditions and by assessing landscape continuity (1850-1928-2000). We compared changes in the strictly protected park core zone with those in the inland buffer zone with ongoing sustainable logging, and a not protected area adjacent to the park. Forest was the dominant land-cover type over the entire study period. We detected a gradient in land-cover continuity from the core zone (81 % continuity) to the inland buffer zone (74 %) and the area outside the park (66 %). Northern hardwood was the dominating forest type in all time points with high continuity (76 %). In contrast, pine forests show a more dynamic pattern with more than 50 % of the initial forests switching to non-forest or early succession forest types by 1928. More than half of the study area was considered as ''natural virgin'' (no changes in land-cover and forest community type) with a higher portion within the park than in the adjacent area. In contrast, areas with low naturalness are more abundant outside the park. Our study demonstrates the value of integrating historical information into naturalness assessments and the results provide useful information for future park management. More broadly speaking, our study advances research on the effectiveness of protected areas, by going beyond simple measures of averted deforestation, and introducing approaches to directly measure naturalness.
File: Gimmi-Radeloff-EnvMgmnt-2013.pdf
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Land-use change around protected areas can reduce their effective size and limit their ability to conserve biodiversity because land-use change alters ecological processes and the ability of organisms to move freely among protected areas. The goal of our analysis was to inform conservation planning efforts for a nationwide network of protected lands by predicting future land use change. We evaluated the relative effect of three economic policy scenarios on land use surrounding the U.S. Fish and Wildlife Service's National Wildlife Refuges. We predicted changes for three land-use classes (forest/range, crop/pasture, and urban) by 2051. Our results showed an increase in forest/range lands (by 1.9% to 4.7% depending on the scenario), a decrease in crop/pasture between 15.2% and 23.1%, and a substantial increase in urban land use between 28.5% and 57.0%. The magnitude of land-use change differed strongly among different USFWS administrative regions, with the most change in the Upper Midwestern US (approximately 30%), and the Southeastern and Northeastern US (25%), and the rest of the U.S. between 15 and 20%. Among our scenarios, changes in land use were similar, with the exception of our restricted-urban-growth scenario, which resulted in noticeably different rates of change. This demonstrates that it will likely be difficult to influence land-use change patterns with national policies and that understanding regional land-use dynamics is critical for effective management and planning of protected lands throughout the U.S.
File: Hamilton_etal_2013_PLOS1.pdf
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The demand for agricultural products continues to grow rapidly, but further agricultural expansion entails substantial environmental costs, making recultivating currently unused farmland an interesting alternative. The collapse of the Soviet Union in 1991 led to widespread abandonment of agricultural lands, but the extent and spatial patterns of abandonment are unclear. We quantified the extent of abandoned farmland, both croplands and pastures, across the region using MODIS NDVI satellite image time series from 2004-2006 and Support Vector Machines classifications. Abandoned farmland was widespread, totaling 52.5 million hectares, particularly in temperate European Russia (32 mill ha), Northern and Western Ukraine, and Belarus. Differences in abandonment rates among countries were striking, suggesting that institutional and socio-economic factors were more important in determining the amount of abandonment than biophysical conditions. Indeed, much abandoned farmland occurred in areas without major constraints for agriculture. Our map provides a basis for assessing the potential of Central and Eastern Europe's abandoned agricultural lands to contributing to food or bioenergy production, or carbon storage, as well as the environmental trade-offs and social constraints of recultivation.
File: alcantara-etal-ERL-2013_0.pdf
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Ecologists commonly collect data on vegetation structure, which is an important attribute for characterizing habitat. However, measuring vegetation structure across large areas is logistically dif?cult. Our goal was to evaluate the degree to which sample-point pixel values and image texture of remotely sensed data are asso- ciated with vegetation structure in a North American grassland-savanna-woodland mosaic. In the summers of 2008-2009 we collected vegetation structure measurements at 193 sample points from which we calculat- ed foliage-height diversity and horizontal vegetation structure at Fort McCoy Military Installation, Wisconsin, USA. We also calculated sample-point pixel values and ?rst- and second-order image texture measures, from two remotely sensed data sources: an infrared air photo (1-m resolution) and a Landsat TM satellite image (30-m resolution). We regressed foliage-height diversity against, and correlated horizontal vegetation struc- ture with, sample-point pixel values and texture measures within and among habitats. Within grasslands, sa- vanna, and woodland habitats, sample-point pixel values and image texture measures explained 26-60% of foliage-height diversity. Similarly, within habitats, sample-point pixel values and image texture measures were correlated with 40-70% of the variation of horizontal vegetation structure. Among habitats, the mean of the texture measure 'second-order contrast' from the air photo explained 79% of the variation in foliage- height diversity while '?rst-order variance' from the air photo was correlated with 73% of horizontal vegeta- tion structure. Our results suggest that sample-point pixel values and image texture measures calculated from remotely sensed data capture components of foliage-height diversity and horizontal vegetation struc- ture within and among grassland, savanna, and woodland habitats. Vegetation structure, which is a key com- ponent of animal habitat, can thus be mapped using remotely sensed data.
File: Wood2012Imagetexturemanuscript121516.pdf
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Since European settlement, hardwood dominated forests of the Upper American Midwest have under- gone compositional changes due to ?re suppression and changes in land use. It is not clear how these changes affect songbirds during spring migration. In 2009 and 2010, we quanti?ed foraging behavior by migratory songbirds during spring migration and collected data on tree and sapling diversity in the Kickapoo Valley Reserve in southwestern Wisconsin. Furthermore, we compared the 1840s distribution of tree species (from Public Land Survey System witness tree records) with current (2010) and estimated future (sapling) tree-composition to better understand how historic and future changes in tree composi- tion may impact migratory songbirds at spring migration stopover sites. Six tree species were selected as foraging substrates in higher proportion than they were available by eight migratory songbirds, including trees adapted to moderate shade such as northern red oak (Quercus rubra), white oak (Quercus alba), American elm (Ulmus americana), and slippery elm (Ulmus rubra), and shade-intolerant species such as big-tooth aspen (Populus grandidentata), and paper birch (Betula papyrifera). Whereas three shade-toler- ant tree species were selected in far lower proportion than they were available by eight migratory song- birds, including sugar maple (Acer saccharum), red maple (Acer rubrum), and basswood (Tilia americana). We found evidence that food accessibility, as measured by a novel approach relating a bird's attacks and search efforts to the average leaf petiole length of a tree species, was strongly inversely related with a bird's foraging success (q = =0.96, p-value <0.001). Although tree-species composition changed considerably from the 1840s to 2010, in both time periods the forest was dominated by a mix of sugar maple and oak species. However, sugar maple saplings currently form a nearly continuous layer in the understory and there is very low recruitment of shade-intolerant or moderately shade-tolerant species, suggesting a future shift towards dominance by shade-tolerant species. Our results suggest the current trajectory of forest succession may result in future conditions that provide lower quality foraging for migratory songbirds during spring migration than they currently experience in the Upper American Midwest.
File: Woodetal2012.pdf
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File: Woolly-necked_Stork_Yunnan.pdf
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Institutional settings play a key role in shaping land cover and land use. Our goal was to understand the effects of institutional changes on agricultural land abandonment in different countries of Eastern Europe and the former Soviet Union after the collapse of socialism. We studied 273 800 km2 (eight Landsat footprints) within one agro-ecological zone stretching across Poland, Belarus, Latvia, Lithuania and European Russia. Multi-seasonal Landsat TM/ETMC satellite images centered on 1990 (the end of socialism) and 2000 (one decade after the end of socialism) were used to classify agricultural land abandonment using support vector machines. The results revealed marked differences in the abandonment rates between countries. The highest rates of land abandonment were observed in Latvia (42% of all agricultural land in 1990 was abandoned by 2000), followed by Russia (31%), Lithuania (28%), Poland (14%) and Belarus (13%). Cross-border comparisons revealed striking differences; for example, in the Belarus-Russia cross-border area there was a great difference between the rates of abandonment of the two countries (10% versus 47% of abandonment). Our results highlight the importance of institutions and policies for land-use trajectories and demonstrate that radically different combinations of institutional change of strong institutions during the transition can reduce the rate of agricultural land abandonment (e.g., in Belarus and in Poland). Inversely, our results demonstrate higher abandonment rates for countries where the institutions that regulate land use changed and where the institutions took more time to establish (e.g., Latvia, Lithuania and Russia). Better knowledge regarding the effects of such broad-scale change is essential for understanding land-use change and for designing effective land-use policies. This information is particularly relevant for Northern Eurasia, where rapid land-use change offers vast opportunities for carbon balance and biodiversity, and for increasing agricultural production on previously cultivated lands.
File: erl12_2_024021_0.pdf
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The growth of human populations around protected areas accelerates land conversion and isolation, negatively impacting biodiversity and ecosystem function, and can be exacerbated by immigration. It is often assumed that immigration around protected areas is driven by attraction in the form of economic bene?ts, but in many cases, people may be pushed from their areas of origin toward protected areas. Mitigating the effects of immigration around protected areas necessitates understanding the actual mechanisms causing it, which can be aided by analysis of patterns of land-cover change. Our goal was to identify the reasons for human population growth and land-cover change around the protected areas in the greater Serengeti ecosystem (henceforth ''the park''), and to relate agricultural conversion from 1984-2003 to trends in human demography. We found that conversion of natural habitats to agriculture was greatest closer to the park (up to 2.3% per year), coinciding with the highest rates of human population growth (3.5% per year). Agricultural conversion and population growth were greatest where there was less existing agriculture, and population density was lowest. Lack of unfarmed land farther from the park, coupled with greater poverty near the park, suggest that movement away from areas with high population densities and land scarcity was likely driving immigration near the park, where arable land was available. Our results are essential for conservation planning for one of Africa's hallmark ecosystems, and should encourage further examination of population growth and land-cover trends near protected areas throughout the developing world
File: EstesA_BioCons_LCLUC_Serengeti.pdf
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