1,721,117 research outputs found
Conserving Moving Species under Changing Landscapes and Climates
No full textTo conserve biodiversity, it is critical to understand the dynamic landscapes and climates through which species move and how the environment influences movement choices. In particular, I am interested in how species respond to human modifications to landscapes and climates. Chapter 1 uses datasets on the spatial and temporal coverage of remotely sensed land cover datasets to examine gaps in the monitoring of environmental priorities. Temporal gaps in Landsat and spatial gaps in commercial high resolution satellites such as QuickBird may hinder land cover change monitoring efforts.Chapter 2 uses Global Climate Models and museum specimens to projects the impact of climate change on the flora of California, a global biodiversity hotspot. With anticipated climate change, up to 66% may experience >80% reductions in range size within a century. These projections are less severe if plants are able to disperse in time. With no constraints on dispersal, plant centroids move an average of up to 150 km. The projections identify regions where species undergoing severe range reductions may persist. Protecting these potential future refugia and facilitating species dispersal may be essential to maintain biodiversity in the face of climate change.Chapter 3 analyzes the movements of 73 elephants fitted with GPS collars against 4 remotely sensed datasets spanning a strong rainfall gradient across 7 southern African countries. Movements show strong seasonal and geographic differences across the study area. Two major human interventions, artificial water and fences, distort these movement patterns by increasing dry season ranging patterns and increasing the density of wet season movements.Chapter 4 uses the datasets described in chapter 3 to explore elephant vegetation preferences. Elephants consistently prefer greener vegetation throughout the year. Vegetation preferences vary seasonally. Elephants prefer less variable vegetation such as forests in the dry season and ephemeral vegetation such as grasslands in the wet season.Chapter 5 uses telemetry and remotely sensed landcover data to ask how climatic factors - snow cover - and land cover - agriculture and roads - influence pronghorn movements in South Eastern Alberta. Analysis using a Bayesian movement model reveals that each of these features significantly influences pronghorn movement choices.</p
A tale of three disciplines: Navigating the Boundaries at the Nexus of Conservation Science, Policy, and Practice
No full textNature is under immediate and increasing threat. Tales of destruction and deforestation abound despite the myriad interventions and investments by government bureaucracies, non-government organizations, and private land-owners. As the extinction crisis looms larger and demands on the public purse grow greater, understanding how science becomes policy and policy practice is more important than ever. As a result, and in response to the increasing insularity of conservation biology that has consciously nourished a careful separation of knowledge and action, of scientist and actor, I use this dissertation to navigate the nexus of conservation science, policy, and practice. I employ case studies in forest hydrology and species conservation, as well as cognitive theory, to examine how conservation science becomes policy. I collected field data from Lake Mead National Recreation Area and from the World Bank to explore how policies are translated into practice.
Current assumptions in conservation biology apportions these three separate but equal disciplines - science, policy, and practice - into one greater and two lesser, one that is pure and two that are sticky. But the transmission of knowledge from the Academy to the domains of conservation policy and practice, though difficult, is our mandate. As much as technical competence matters in conservation biology, so too does political literacy. After all, conservation occurs within a dynamic social, political, and institutional landscape. Nonetheless, the current emphasis in conservation biology is on answering questions in the natural sciences and, to a lesser degree, in economics. This focus is important, as is protecting scholarship from the daily pressures of a society that demands quick and ready answers. But scientific data is only one commodity among many that policy-makers and conservation practitioners trade in a tournament of values. Its usefulness lies in the wider social and political environment. Moreover, conservation biology is not simply an applied subset of biology or ecology. It is a mission-driven discipline that dedicates itself to the pursuit of science to save wildlife and wild lands. It encapsulates certain values as axioms. We hold these truths to be self-evident: that the diversity of life matters and that the struggle to end extinctions is meaningful.
Therefore, though conservation science, the design of conservation policies, and the practice of conservation are separate disciplines, they are closely related. For we must understand their different rules of evidence, speak their distinctive languages, and achieve credibility in all three disciplines while maintaining a sense of intellectual integrity in each. This requires respect for their differences as well as recognizing their shared mission in the service of wildlife and wild lands.</p
A PRELIMINARY ANALYSIS OF VERREAUX’S SIFAKA HABITAT IN KIRINDY MITEA NATIONAL PARK, MADAGASCAR
No full textKirindy Mitea National Park contains one of the largest continuous tracts of dry forest
left in Madagascar. Most of the dry, deciduous forest of western Madagascar is degraded and
fragmented after years of deforestation from slash and burn agriculture and logging. Kirindy
Mitea is a new research site, so little is known about the park as a whole and the species living
there. This focal species of this project is the park’s largest lemur, Verreaux’s sifaka
(Propithecus verreauxi verreauxi). The goals of this project were to determine the average home
range size and group size of the species in Kirindy Mitea, and then compare those numbers to
two other sites in southwestern Madagascar, Beza Mahafaly Special Reserve and Kirindy
Forest/CFPF. In addition, GIS analyses were performed to look at the land cover changes that
took place in Kirindy Mitea during a 16 year period. The results of that analysis were used to
perform a GIS based threat analysis of the forest in the park, in order to determine what areas are
at the highest risk of deforestation in the future.
I found that the average home range size of Verreaux’s sifaka in Kirindy Mitea is larger
than the average home range sizes in Beza Mahafaly and Kirindy CFPF (p=0.010). In addition,
the home ranges have less overlap with neighboring groups in Kirindy Mitea, most likely due to
a difference in habitat and a lack of tamarind trees. The land cover change analysis revealed that
during 1990-2006, there has actually been a gain of over 4,000 ha of forest. However, during the
most recent time period, 2000-2006, there was an overall loss of almost 2,000 ha of forest, and
these areas of forest loss were concentrated around the park boundary and the savanna. The
threat analysis determined that the factors that will most likely lead to deforestation in the future
in Kirindy Mitea are proximity to the park boundary, the roads in the park, and the savanna.
Using the results of the threat analysis, I was able to determine that about 10,500 ha of viable
lemur habitat in the park is at high risk of deforestation in the future.
Currently, the forest in Kirindy Mitea is quite continuous, and there is an adequate
amount left to support large lemur species like Verreaux’s sifaka. It will be important for park
managers to continue protecting the forest so that it does not become fragmented like most of the
dry forest left in Madagascar. I recommend creating a buffer area around the park boundary and
investing in additional security and park staff to monitor the remaining forest around the park
boundary and near roads and savanna. Kirindy Mitea is a rare park in that it actually contains a
large amount of continuous forest, so conserving those remaining large tracts of forest should be
a top priority for park managers
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Identifying areas of socio-ecological value for the translocation of perceived conflict cheetah (A. jubatus) and leopard (P. pardus) in Namibia
No full textHuman-wildlife conflict is an ever-present threat to large carnivores in Namibia due to their distribution across privately owned properties. Translocation techniques are one approach to solving this conservation challenge, but are often regarded as unsuccessful due to new sources of competition, stress, or human conflict for translocated animals. In attempt to mitigate some of these failures, I developed an ArcGIS- (v.10.1, ESRI 2012) based carnivore translocation suitability tool (CaTSuiT) that identifies habitat patches which meet the ecological requirements of leopard and cheetah and accounts for human-development parameters. CaTSuiT ranks potential habitat patches based on landowner tolerance of carnivores (determined by survey) and the uncertainty associated with a patch's designated tolerance due to the number of un-surveyed landowners. The model indicates a large number of available habitat patches for leopard; however, suitable cheetah habitat patches are limited by the amount of suitable areas farther from the recommended minimum homing distance away from a conflict animal's capture location. This tool should be used as a guide to inform conservation managers about where to focus their efforts to help landowners incorporate more tolerant farming practices and improve coexistence between local land-owners and large carnivores
Elevational Range Shifts Driven by Climate Change in Tropical Mountains: Assessment and Conservation Opportunities
No full textGlobal climate change can cause shifts in species distributions, and increases in some of their competitors, predators, and diseases that might even cause their extinction. Species may respond to a warming climate by moving to higher latitudes or elevations. Shifts in geographic ranges are common responses in temperate regions. For the tropics, latitudinal temperature gradients are shallow: the only escape for species may be to move to higher elevations. There are few data to suggest that they do, and our understanding of the process is still very limited. Yet, the greatest loss of species from climate disruption may be for tropical montane species. To better understand the potential process of elevational range shifts in the tropics and their implications we have to: 1) Build theoretical models for the process of range shifting, 2) Evaluate potential constraints that species could face while moving to higher elevations, 3) Obtain empirical evidence confirming the uphill shift of species ranges, 4) Determine the number of extinctions that could arise from elevational range shifts (mountain top extinctions) and 5) Identify vulnerable species and areas, and determine their representation by the Protected Areas Network. The purpose of this dissertation is to address these issues, by applying novel methods and collecting empirical evidence. In the second chapter I incorporated temperature gradients and land-cover data from the current ranges of species in a model of range shifts in response to climate change. I tested 4 possible scenarios of amphibian movement on a tropical mountain and estimated the constraints to range shifts imposed by each scenario. Confirming the occurrence of elevational range shifts with empirical data is also essential, but requires historical data as a baseline for comparison. I repeated a historical transect in Peru, sampling birds at the same locations they were sampled 40 years ago, and compared their elevational ranges between sampling occasions to evaluate if they were moving uphill as a response to warming temperatures. Finally, based on the results from this comparison, I estimated the potential extinctions derived from elevational range shifts, using information on the species distribution, the topography and land cover within the ranges and surrounding areas. I evaluated the extent of mountain top extinctions for 172 bird species with restricted ranges in the northern Andes. I also considered how Colombia's protected Area Network represents species and sites that are vulnerable in the face of climate change.More than 30% of the range of 21 of 46 amphibian species in the tropical Sierra Nevada de Santa Marta is likely to become isolated as climate changes. More than 30% of the range of 13 amphibian species would shift to areas that currently are unlikely to sustain survival and reproduction. Combined, over 70% of the current range of 7 species would become thermally isolated or shift to areas that currently are unlikely to support survival and reproduction. The constraints on species' movements to higher elevations in response to climate change can increase considerably the number of species threatened by climate change in tropical mountains.In the comparison of bird distributions in the Cerrros del Sira, in Peru, I found an average upward shift of 49 m for 55 bird species over a 41 year interval. This shift is significantly upward, but also significantly smaller than the 152 m one expects from warming in the region. The range shifts in elevation were similar across different trophic guilds. Endothermy may provide birds with some flexibility to temperature changes and allow them to move less than expected. Instead of being directly dependent on temperature, birds may be responding to gradual changes in the nature of the habitat or availability of food resources, and presence of competitors. If so, this has important implications for estimates of mountaintop extinctions from climate change. The estimated number of mountain top extinctions from climate disruption in the northern Andes is low, both the absolute number (5 species) and the relative number (less than 0.5% of Colombian land birds). According to future climate predictions these extinctions will not likely occur in this century. The extent of species loss in the Andes is not predicted by absolute mountaintop extinctions modeled by the kind of processes most other studies use. Rather, it is highly contingent -- the species will survive or not depending on how well we protect their much reduced ranges from the variety of other threats.</p
Conservation of endemic species in China
No full textChina is one of the most biodiverse countries in the world, harboring more than 10% of the species in the world. Among them, 11% of the vertebrate genera and 7% plant genera are endemic to China. During its rapid social and economic development, increasing habitat loss and fragmentation have occurred. However, it wakes up to the threats of biodiversity in recent years. Protected areas, as an essential conservation tool to reduce habitat loss and species extinction have expanded dramatically in China. Protected areas with various other concepts such as umbrella species and payment for ecosystem services have been promoted to conserve the biodiversity. However, questions remain that whether they work, how they work and how we could do better. It is crucial to answer these questions with the data and technology that are more available to us now. Thus, my dissertation divides into four chapters and tackles the following four questions. 1) Where do the most of the endemic species concentrate in China? Do umbrellas species such as giant pandas effectively protect other species? 2) With the increasing of tree plantation and available remote sensing data, how does it change the available habitat for forest species, their threat levels and priority setting? 3) Within the conservation priority areas, new threats that are hardly detected by traditional evaluation index such as forest cover emerge. How does a prevalent human disturbance - livestock grazing impact the conservation of giant pandas? What are the socio-economic drivers and solutions to this issue? 4) To better monitor the population and evaluate conservation efforts, new techniques need to be added. Can we use footprints from wild pandas to identify individuals and provide a cost-effective alternative to the current methods?In Chapter 1, I first used detailed data on geographical ranges for endemic forest species to identify patterns of species richness. After refining each species' range by its known elevational range and remaining forest habitats as determined from remote sensing, I identified the top 5% richest areas as the centers of endemism. Over 96% of the panda habitat overlapped the endemic centers. Thus, investing in almost any panda habitats will benefit many other endemics. Existing panda national nature reserves cover all but one of the endemic species that overlap with the panda’s distribution. For whole China, of particular interest are 14 mammal, 20 bird, and 82 amphibian species that are inadequately protected. Most of these the IUCN currently deems threatened. But 7 mammal, 3 bird, and 20 amphibian species are currently non-threatened, yet their geographical ranges are In Chapter 2, I used remote sensing data to differentiate oil palm and rubber plantation from natural forests in Southeast Asia and reevaluated the threat level of endemic forest species identified by IUCN. Tropical, mainland Southeast Asia is under exceptional threat, yet relatively poorly known. This region contains over 122, 183, and 214 endemic mammals, birds, and amphibians, respectively, of which the IUCN considers 37, 21, and 37 threatened. When corrected for the amount of remaining natural habitats, the average sizes of species ranges shrink to Chapter three focuses on a specific threat - livestock grazing in the endemic center that I identified in the first chapter. With the Natural Forest Conservation Program and Grain to Green programs, the deforestation that was once the biggest threat to pandas has been halted. However, a previously unrecognized threat is emerging. Livestock grazing has become the most prevalent human disturbance throughout panda habitats. I applied field sign survey, vegetation survey, GPS collar tracking, and species distribution modeling to study how the livestock grazing impacts the habitat use of giant pandas. This study shows that livestock grazing especially from horses has caused a dramatic decline in bamboos and reduced its regeneration. In the past 15 years, pandas have changed its habitat use and are driven out of areas that are heavily used by livestock. 49% of panda habitat has been lost especially in the lower elevation areas from 2004 till now due to impacts of livestock. Loss of income because of the policies Natural Forest Conservation Project and Grain for Green projects, reduced tourists because of dam construction and earthquake, encouraged horse riding practice during the development of ICDP have contributed to the increasing dependence on livestock sector. Livestock ban with payment for ecosystem services or feedlot operation could be possible solutions for this issue.Chapter four explores the innovative technique to identify giant panda individuals to facilitate better conservation. Two methods have been used previously to identify individuals and population for giant pandas, fecal bamboo bite size combined with home range analysis and microsatellite analysis of fecal DNA. However, the first one suffers from the lack of accuracy and the latter one is limited by the freshness of the fecal sample and high cost. I developed the footprint identification technique in JMP based on two multivariate methods: discriminant analysis and the canonical centroid plot method using the anatomy measurements of footprints. I used 30 captive pandas to develop the algorithm and 11 individuals for validation. The overall accuracy of FIT for individual identification is 90% and sex discrimination is 85%. This technique is embedded in FIT as an add-in and free for conservation practitioners now. In summary, this dissertation includes the following four papers. Chapter 1, Li and Pimm. 2016. China's endemic vertebrates sheltering under the protective umbrella of the giant panda. Conservation Biology 30:329-339.Chapter 2, Li et al., 2016. Remotely sensed data informs Red List evaluations and conservation priorities in Southeast Asia. PloS one, 11(8), e0160566.Chapter 3, Li et al., Emerging threat from livestock on giant panda conservationChapter 4, Li et al., Identifying individual and sex of giant pandas through Footprint Identification Technique.With supporting information from the following publication during my Ph.D.:Li, B. et al. 2014. Effects of feral cats on the evolution of anti-predator behaviours in island reptiles: insights from an ancient introduction. Proc. R. Soc. B 281: 20140339.Ocampo-Peñuela, N., Jenkins, C. N, Vijay, V., Li, B.V., & Pimm., S.L. 2016. Incorporating explicit geospatial data shows more species at risk of extinction than the current Red List. Science Advances, 2(11), e1601367.Pimm, S.L., Harris, G., Jenkins, C.N., Ocampo-Peñuela, N. & Li, B.V. 2016 Unfulfilled promise of data-driven approaches: response to Peterson et al. Conservation Biology, In press.</p
Understanding the Impacts of Agricultural Expansion on Biodiversity and Habitat Loss
No full textIn recent years, the expansion of agricultural lands into areas rich in biodiversity has led to a conservation dilemma between the need for food security for an expanding human population and the goal of conserving species and habitat to curb biodiversity loss. In this dissertation, I evaluate several different concerns about agricultural expansion from a conservation perspective. One of the central goals of conservation is the preservation of species and habitats within the context of anthropogenic threats. Agriculture has come to exemplify these threats to conservation both directly through habitat loss and indirectly through increased human/wildlife conflict, reduced in connectivity between intact areas and loss of ecosystem services in farming areas. Many of these effects can be observed through monitoring of land use change and populations of critical species. Still other effects will only be observed in the future, as agricultural areas continue to expand. In recognition of the importance of addressing these questions, there has been an increasing push by both agroecologists and conservation scientists to adopt increasingly interdisciplinary approaches in their research, focusing both on ways to minimize, mitigate and predict possible negative effects of agricultural production on biodiversity and the environment.In Chapter 1, I examine the global impacts of a rapidly expanding commodity crop, oil palm, on deforestation and biodiversity. Here I address the deforestation associated with development of oil palm over the past 25 years in 20 different countries, discussing the implications for future deforestation and risk of biodiversity loss in the context of a changing climate. I conclude that the potential expansion of oil palm agriculture threatens many of the world’s most biodiverse places, but that the exact areas of highest conservation priority are dependent on the biodiversity criteria by which such areas are selected.In Chapter 2, I build upon this analysis with a study of oil palm in the context of other agricultural development in Peru--a country found to have sharply increasing deforestation related to oil palm in Chapter 1. Here I show that oil palm is contributing to deforestation more than other crops. I also show how the spatial pattern of this impact differs from other crops, with larger and more clustered patches of deforestation. I expand on the analysis of areas at long-term of deforestation from oil palm from Chapter 1 by examining specific biophysical variables that show how oil palm is suitable in habitats not typically exploited for agriculture in this region. I also assess short-term risk of deforestation based on variables associated with human population and accessibility. Finally, I evaluate the effectiveness of protected areas and officially recognized indigenous areas in meeting the threat from oil palm across the different ecoregions of Peru’s Moist Tropical Forest biome.In Chapter 3, I examine the impacts of agricultural activity on an iconic predator species, the cheetah (Acinonyx jubatus). This species is designated as threatened by the IUCN and plays an important role in the ecosystems in which it occurs. Currently, cheetah are facing loss of habitat and restrictions of connectivity from agriculture, especially livestock production. Farmers in areas where many cheetah occur are also a risk to the species through persecution and killing individuals. We found that cheetah are decreasing in number, supporting an argument to uplist the cheetah to endangered. I did not only want to focus on the problems associated with agricultural production, but also consider a proposed solutions. Thus, in Chapter 4, I consider an option that could balance the needs for food security of human populations and habitat for species conservation: increased intensity of production on existing agricultural land, such as growing multiple crops per year. This suggestion is not without possible drawbacks or pitfalls, motivating the need to study multiple cropping systems and the consequences of their expansion. However, the study of cropping intensity over large geographical areas is complicated by the lack of high-quality maps of cropping intensity at such scales. I evaluate cropping intensity throughout South America using MODIS Enhanced Vegetation Index (EVI) data in Google’s Earth Engine over the period 2003-2015. I conclude that there is great potential for this approach to reduce habitat loss in South America, but there are also potential complications that could arise from its widespread adoption.</p
Broad Scale Conservation: Protected Areas and Species Interactions
No full textThis dissertation consists of four chapters. The first three chapters examine protected areas (or parks) from multiple perspectives. Parks are the first, and often only, line of defense in efforts to conserve biodiversity. Understanding of their promise and problems is necessary to achieve conservation outcomes. Chapter One determines vegetation patterns in and around parks of differing management categories across the Amazon, Congo, South American Atlantic Coast, and West African forests. Within these forests, protected areas are the principle defense against forest loss and species extinctions. In the Amazon and Congo, parks are generally large and retain high levels of forest cover, as do their surroundings. In contrast, parks in the Atlantic Coast forest and West Africa show sharp boundaries in forest cover at their edges. This effective protection of forest cover is partially offset by their very small size: little area is deep inside park boundaries. Compared to West Africa, areas outside parks in the Atlantic Coast forest are unusually fragmented. Chapter Two addresses a human dimension of protected areas. Given certain characteristics, parks areas may either attract or repel human settlement. Disproportionate increases in population growth near park boundaries may threaten their ability to conserve biodiversity. Using decadal population datasets, we analyze population growth across 45 countries and 304 parks. We find no evidence for population growth near parks to be greater than growth of rural areas in the same country. Furthermore, we argue that what growth does occur near parks likely results from a general expansion of nearby population centers. Parks may experience unusual population pressures near their edges; indeed, individual case studies provide examples. There is no evidence, however, of a general pattern of disproportionate population growth near their boundaries.Chapter Three provides a review of common approaches to evaluating protection's impact on deforestation, identifies three hurdles to empirical evaluation, and notes that matching techniques from economic impact evaluation address those hurdles. The central hurdle derives from the fact that protected areas are distributed non-randomly across landscapes. Matching controls for landscape characteristics when inferring the impact of protection. Applications of matching have revealed considerably lower impact estimates of forest protection than produced by other methods. These results indicate the importance of variation across locations in how much impact protection could possibly have on rates of deforestation.Chapter Four departs from the focus of protected areas and instead addresses a more theoretical aspect of community ecology. Ecological theories suggest that food webs might consist of groups of species forming blocks, compartments or guilds. Chapter Four considers ecological networks (subsets of complete food webs) involving species at adjacent trophic levels. Reciprocal specializations occur when (say) a pollinator (or group of pollinators) specializes on a particular flower species (or group of such species) and vice versa. We characterize the level of reciprocal specialization for various classes of networks. Our analyses include both antagonistic interactions (particularly parasitoids and their hosts), and mutualistic ones (such as insects and the flowers that they pollinate). We also examine whether trophic patterns might be palimpsests. That is, there might be reciprocal specialization within taxonomically related species within a network, but these might be obscured when these relationships are combined. Reciprocal specializations are rare in all these systems even when tested using the most conservative null model.</p
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