44 research outputs found

    Using Unoccupied Aerial Vehicles to Map and Monitor Changes in Emergent Kelp Canopy after an Ecological Regime Shift

    Get PDF
    Kelp forests are complex underwater habitats that form the foundation of many nearshore marine environments and provide valuable services for coastal communities. Despite their ecological and economic importance, increasingly severe stressors have resulted in declines in kelp abundance in many regions over the past few decades, including the North Coast of California, USA. Given the significant and sustained loss of kelp in this region, management intervention is likely a necessary tool to reset the ecosystem and geospatial data on kelp dynamics are needed to strategically implement restoration projects. Because canopy-forming kelp forests are distinguishable in aerial imagery, remote sensing is an important tool for documenting changes in canopy area and abundance to meet these data needs. We used small unoccupied aerial vehicles (UAVs) to survey emergent kelp canopy in priority sites along the North Coast in 2019 and 2020 to fill a key data gap for kelp restoration practitioners working at local scales. With over 4,300 hectares surveyed between 2019 and 2020, these surveys represent the two largest marine resource-focused UAV surveys conducted in California to our knowledge. We present remote sensing methods using UAVs and a repeatable workflow for conducting consistent surveys, creating orthomosaics, georeferencing data, classifying emergent kelp and creating kelp canopy maps that can be used to assess trends in kelp canopy dynamics over space and time. We illustrate the impacts of spatial resolution on emergent kelp canopy classification between different sensors to help practitioners decide which data stream to select when asking restoration and management questions at varying spatial scales. Our results suggest that high spatial resolution data of emergent kelp canopy from UAVs have the potential to advance strategic kelp restoration and adaptive management

    Climate Change, Habitat Loss, Protected Areas and the Climate Adaptation Potential of Species in Mediterranean Ecosystems Worldwide

    Get PDF
    Mediterranean climate is found on five continents and supports five global biodiversity hotspots. Based on combined downscaled results from 23 atmosphere-ocean general circulation models (AOGCMs) for three emissions scenarios, we determined the projected spatial shifts in the mediterranean climate extent (MCE) over the next century. Although most AOGCMs project a moderate expansion in the global MCE, regional impacts are large and uneven. The median AOGCM simulation output for the three emissions scenarios project the MCE at the end of the 21st century in Chile will range from 129–153% of its current size, while in Australia, it will contract to only 77–49% of its current size losing an area equivalent to over twice the size of Portugal. Only 4% of the land area within the current MCE worldwide is in protected status (compared to a global average of 12% for all biome types), and, depending on the emissions scenario, only 50–60% of these protected areas are likely to be in the future MCE. To exacerbate the climate impact, nearly one third (29–31%) of the land where the MCE is projected to remain stable has already been converted to human use, limiting the size of the potential climate refuges and diminishing the adaptation potential of native biota. High conversion and low protection in projected stable areas make Australia the highest priority region for investment in climate-adaptation strategies to reduce the threat of climate change to the rich biodiversity of the mediterranean biome

    Planning for Change: The Implications of a Changing Climate for Ecological Conservation Planning

    No full text
    The effects of current and future climate change on biological phenology, distribution, community composition, mortality, and extinction have been thoroughly analyzed. However, there has been little analysis of site-specific methods to preserve species and habitats faced with inevitable natural and anthropogenic climate change. The Nature Conservancy (TNC) is currently prioritizing parcels for protection within the Mount Hamilton region. This region contains oak woodlands, riparian habitats and rare and endangered species that are sensitive to the direct and indirect impacts of climate variation. Climate change predictions are based on a low to moderate emissions scenario and a global circulation model downscaled to a 40 kilometer horizontal resolution grid. Binary logistical regression is used to determine which climatic variables influence the distribution of habitat for six high priority species. Climate envelopes based on current and the predicted future climate are compared to determine the amount habitat lost due to climate change. Blue oak (Quercus douglasii) woodlands are the least impacted, but are still projected to lose up to 55% of their habitat. Bay Checkerspot Butterflies (Euphydryas editha bayensis) are the most impacted, and are projected to lose 100% of their habitat. Migration to areas of new habitat is restricted by elevation, low dispersal rates, and the lack of suitable habitat conditions. TNC and other organizations can help to avoid local extirpation of high priority species by preserving high elevation future habitat, migration corridors, and transplanting species upslope. With these efforts, the Mount Hamilton region could continue to support its rich biodiversity despite a rapidly changing climate

    Effects of climate change on the hydrology of upper Alameda Creek

    No full text
    Scientists predict that future climate change will effect both human and natural systems. Using two rainfall-runoff modeling methods, this analysis predicts the effects of climate change on the hydrology of upper Alameda Creek, a small drainage area in California’s Coast Range. I analyzed daily rainfall, temperature, and stream flow data collected from field gages for 8 years to develop a numerical predictive model. Using the Army Corps of Engineers Hec-HMS model and autoregressive statistical techniques, I minimized the difference between the predicted and the observed creek discharge. I then generated an altered temperature and precipitation regime based on a high-end climate change prediction downscaled to a 60 square mile grid. For upper Alameda Creek, annual precipitation is predicted to fall by 28.2% and annual temperature is predicted to increase by 5.2°C by 2100. The autoregressive model had the lowest error when compared to the observed data, and predicts a 22% decrease in total discharge and considerably smaller peak flows with climate change. The Hec-HMS model predicts a 46% reduction in total discharge and large reductions in peak flows with climate change. Reduced discharge and peak flows will have adverse impacts on downstream uses, including drinking water supplies for San Francisco, recreational uses at Sunol Regional Wilderness, and habitat for native rainbow trout, alluvial sycamore, California red-legged frog, California tiger salamander, and other rare and endangered species

    Evaluating conservation spending for species return: A retrospective analysis in California

    No full text
    Conservation spending in California, USA exceeds conservation expenditures in many countries. To date, there has been no objective method to assess the efficiency of such spending for achieving species conservation outcomes. We conducted the first such retrospective analysis of conservation spending, examining the distribution of $ 2.8 billion spent on land protection by the state of California and partners from 1990 to 2006. Using a return on investment algorithm with species protection as the sole objective, we describe a "cost-efficient" funding scenario that would have protected four times more distinct species and three times more threatened and endangered species compared to the observed allocation. Differences between the species-diversity spending and the observed spending patterns reflect the myriad funding objectives, beyond protecting species, of the state. Identifying cost-effective conservation strategies are essential given the need to maintain species diversity in the face of global change

    Archaeological applications of polynomial texture mapping: analysis, conservation and representation

    No full text
    Polynomial Texture Mapping is an image capture and processing technique that was developed by HP Labs in 2000. It enables the recording and representation of subtle surface details using a standard digital camera and lighting, and software that is free for non-commercial use. Cultural heritage applications have been associated with the technology from its earliest stages, including examples in areas such as cuneiform, numismatics, rock art, lithics and Byzantine art. The paper begins by outlining the technical principles involved. It then brings together the extant work in the field. Through examples developed by the University of Southampton in partnership with a range of UK and international bodies it demonstrates the benefits of the technology in the areas of archaeological analysis, conservation and representation. Finally it considers the future possibilities of this technology and ongoing developments
    corecore