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Land allocation for urban growth is central to sustainable development strategy because urban growth can impact space available for food production, ecosystem services and biodiversity conservation. Urbanization is a growing stressor due the 2.5 billion additional people projected to live in urban areas by 2050. Potential climate change impacts to natural systems increase the need for sustainable urbanization, which should integrate land use needs for urban growth with climate adaptation objectives such as maintaining biodiversity, food production and ecosystem services. Here we compare climate-neutral and climate-adaptive urbanization scenarios to see which produces the most sustainable urbanization, defined as being the most effective at meeting development, conservation, and two climate adaptation objectives. We modeled five urban growth scenarios portraying an increase of 25.8 million people by 2050 for California, USA comprising three climate-neutral scenarios: business-as-usual, compact-new-growth and infill (redevelopment); and two climate-adaptive scenarios: preservation of agricultural climate refugia or future plant dispersal corridors. Infill was the least impacting for the multiple objectives tested; preserving 46–57% more land for other uses. Each climate-adaptive scenario reduced land consumption for its respective target, but increased impacts to the opposite climate-adaptive scenario target. Infill has the potential to contribute towards sustainable urbanization, particularly if combined with other climate adaptation targets. [ABSTRACT FROM AUTHOR]

The process of expanding a network of conservation areas includes identifying valuable areas for conservation, devising policies and implementing conservation actions on the ground. While the first two components are often analyzed in conservation science, the literature seldom focuses on the implementation process, particularly, how the governance structure acts as driver of conservation outcomes. In this paper, we analyze the process of development of the conservation network in California between 1910 and 2010 to test whether governance structure explains the variation in the attribution of land for conservation over time. We find that governance structure does play an important role in the development of the conservation network over the century. We find evidence that polycentric and diverse governance structures result in better conservation outcomes (i.e. more area of land acquired for conservation). Arrangements that included multiple levels of agencies (e.g. Federal, State, and County) better predict the area of conservation land per decade. Location of conservation action per county had an effect on conservation outcomes over the last decades, and we also find a strong negative effect of per capita income in the implementation of conservation actions. These results suggest that it is possible to leverage governance structure to meet future conservation challenges through the maintenance of a diverse and polycentric governance structure. • We conduct a longitudinal study on polycentric governance for conservation. • We find evidence for polycentric governance leading to more conservation outcomes. • Different governance structures matter in different points in time due to legacies. • Conservation outcomes are hindered by economic factors and land competition. • Governance structure might be leveraged to meet future conservation challenges. [ABSTRACT FROM AUTHOR]

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Earth's arid and semiarid ecosystems are subject to novel combinations of disruptive factors and unprecedented rates of change. Biotic soil crust is believed to be sensitive to impacts caused by land use and climate changes. This study examined the potential for spectral detection of different biological soil crusts (BSC: cyanobacteria, moss and lichen) and bare soil components at a long-term manipulative experiment at the Mojave Global Change Facility (MGCF) in southwestern Nevada. We evaluated the potential for spectral detection of experimental treatments using laboratory and field measured reflectance spectra in the second and third year of the experiment, and airborne hyperspectral data obtained in the third year of the manipulations for soil disturbance, increased summer rainfall, and dry nitrogen deposition. Laboratory spectra of individual components of biological soil crust and bare soil measured under controlled laboratory conditions were spectrally different over much of the spectrum and exhibited features at 0.42, 0.50, and 0.68 μm, which could differentiate these materials. Field measured spectra were more similar in overall shape in each of the MGCF treatments and individual BSC could not be distinguished. The field spectra most closely resemble cyanobacteria from laboratory measurements, which are known to cover up to 60% of the inter-shrub spaces. There were significant treatment differences between control, soil disturbance, and irrigation treatments in field spectral measurements and a spectral feature in the 2.00–2.08 μm region could distinguish these treatments. The treatments were also apparent in high spatial resolution (~4 m ground IFOV) airborne hyperspectral imagery using a minimum noise fraction (MNF) analysis, although treatments were not distinct in terms of laboratory or field-based specific features. Disturbance treatments were easily apparent in color-infrared imagery although other treatments were not... [Copyright &y& Elsevier]

Environmental limiting factors (ELFs) are the thresholds that determine the maximum or minimum biological response for a given suite of environmental conditions. We asked the following questions: 1) Can we detect ELFs on percent tree cover across the eastern slopes of the Lake Tahoe Basin, NV? 2) How are the ELFs distributed spatially? 3) To what extent are unmeasured environmental factors limiting tree cover? ELFs are difficult to quantify as they require significant sample sizes. We addressed this by using geospatial data over a relatively large spatial extent, where the wall-to-wall sampling ensures the inclusion of rare data points which define the minimum or maximum response to environmental factors. We tested mean temperature, minimum temperature, potential evapotranspiration (PET) and PET minus precipitation (PET-P) as potential limiting factors on percent tree cover. We found that the study area showed system-wide limitations on tree cover, and each of the factors showed evidence of being limiting on tree cover. However, only 1.2% of the total area appeared to be limited by the four (4) environmental factors, suggesting other unmeasured factors are limiting much of the tree cover in the study area. Where sites were near their theoretical maximum, non-forest sites (tree cover < 25%) were primarily limited by cold mean temperatures, open-canopy forest sites (tree cover between 25% and 60%) were primarily limited by evaporative demand, and closed-canopy forests were not limited by any particular environmental factor. The detection of ELFs is necessary in order to fully understand the width of limitations that species experience within their geographic range.

• Nonnative species may change ecosystem functionality at the expense of native species. Here, we examine the similarity of functional traits of native and nonnative submersed aquatic plants (SAP) in an aquatic ecosystem. • We used field and airborne imaging spectroscopy and isotope ratios of SAP species in the Sacramento-San Joaquin Delta, California (USA) to assess species identification, chlorophyll (Chl) concentration, and differences in photosynthetic efficiency. • Spectral separability between species occurs primarily in the visible and near-infrared spectral regions, which is associated with morphological and physiological differences. Nonnatives had significantly higher Chl, carotene, and anthocyanin concentrations than natives and had significantly higher photochemical reflectance index (PRI) and δ(13) C values. • Results show nonnative SAPs are functionally dissimilar to native SAPs, having wider leaf blades and greater leaf area, dense and evenly distributed vertical canopies, and higher pigment concentrations. Results suggest that nonnatives also use a facultative C(4) -like photosynthetic pathway, allowing efficient photosynthesis in high-light and low-light environments. Differences in plant functionality indicate that nonnative SAPs have a competitive advantage over native SAPs as a result of growth form and greater light-use efficiency that promotes growth under different light conditions, traits affecting system-wide species distributions and community composition., (© 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.)