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1.
J Emerg Manag ; 19(8): 135-155, 2022.
Article in English | MEDLINE | ID: mdl-36239504

ABSTRACT

Frequent hurricanes affect agricultural productivity, food security, economic security, and human wellbeing in the Caribbean islands. We assessed recent hurricane effects on the agricultural sector, and the challenges faced by farmers, foresters, and advisors related to hurricane preparedness and recovery in Puerto Rico and US Virgin Islands (USVI). We used qualitative and quantitative survey methods to compile perspectives from agricultural advisors related to hurricane effects on farmlands, preparedness and recovery measures taken by land managers, and the needs regarding preparing for and responding to future hurricanes. Survey responses from over 200 advisors at eight institutions provided insight into the most devastating hurricane effects across farmlands, including issues related to power outages, communication, road access, and fallen trees. Our results highlight strategies considered critical for hurricane preparedness and recovery but not prevalent in application among land managers. Advisors' perceptions suggested that farmers and ranchers apply essential recovery practices, but critical short-term preparedness practices are limited, and long-term preparedness practices are uncommon. Advisors also indicated the need for more training and educational resources to improve hurricane recovery response. We conclude that better planning to minimize the vulnerability to future hurricanes can be achieved through an increased understanding of how preparedness and recovery practices help mitigate hurricane effects, improved interagency coordination for hurricane response and preparedness, and integrated educational campaigns with advisors and land managers.


Subject(s)
Cyclonic Storms , Caribbean Region , Humans , Prevalence , Surveys and Questionnaires , West Indies
2.
J Am Acad Orthop Surg ; 29(24): e1303-e1312, 2021 Dec 15.
Article in English | MEDLINE | ID: mdl-34061804

ABSTRACT

INTRODUCTION: Based on preoperative and perioperative risk factors that have been found to correlate with the development of acute kidney injury (AKI), our institution developed a protocol aimed at managing and improving outcomes in all elective THA and TKA patients. This article highlights the continued success and growth of our protocol aimed at decreasing AKI and hypotension in elective total joint arthroplasty patients. METHOD: A multidisciplinary team comprising orthopaedic surgeons, nephrologists, anesthesiologists, cardiologists, and internal medicine hospitalists created a comprehensive protocol aimed at decreasing complications after elective joint arthroplasty and improving clinical outcomes across multiple hospitals. Patient demographics, hospital length of stay, readmission rates, mortality, and postoperative AKI and hypotension incidences were recorded and compared between preprotocol phase I (initial protocol implementation) and phase II (protocol expansion across 10 hospitals) patient cohorts. RESULTS: Overall, 3,222 patients over 56 months and 10 hospitals were included. Our phase II AKI rate (0.6%) was significantly lower than our preprotocol rate (6.2%, P < 0.01) and statistically similar to our phase I rate (1.2%, P = 0.61). Our hypotension rate in phase II (6.8%) was significantly lower than our preprotocol rate (12.7%, P < 0.01) but statistically similar to our phase I rate (5.9%, P = 0.40). Furthermore, a significant decrease was observed in hospital length of stay (P < 0.01) over time, but no difference was observed in readmission (P = 0.59) and mortality rates (P = 1.00) over time. DISCUSSION: This protocol-driven interventional study provides a detailed and successful multidisciplinary method to manage and decrease rates of AKI and hypotension in a large patient cohort across multiple hospital centers.


Subject(s)
Acute Kidney Injury , Arthroplasty, Replacement, Hip , Arthroplasty, Replacement, Knee , Hypotension , Acute Kidney Injury/epidemiology , Acute Kidney Injury/etiology , Acute Kidney Injury/prevention & control , Arthroplasty, Replacement, Hip/adverse effects , Arthroplasty, Replacement, Knee/adverse effects , Humans , Hypotension/epidemiology , Hypotension/etiology , Hypotension/prevention & control , Length of Stay , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Postoperative Complications/prevention & control , Retrospective Studies , Risk Factors
3.
Int J Climatol ; 41(2): 1305-1327, 2021 Feb 17.
Article in English | MEDLINE | ID: mdl-34017157

ABSTRACT

The Weather Research and Forecasting (WRF) model and a combination of the Regional Spectral Model (RSM) and the Japanese Meteorological Agency Non-Hydrostatic Model (NHM) were used to dynamically downscale selected CMIP5 global climate models to provide 2-km projections with hourly model output for Puerto Rico and the U.S. Virgin Islands. Two 20-year time slices were downscaled for historical (1986-2005) and future (2041-2060) periods following RCP8.5. Projected changes to mean and extreme temperature and precipitation were quantified for Holdridge life zones within Puerto Rico and for the U.S. Virgin Islands. The evaluation reveals a persistent cold bias for all islands in the U.S. Caribbean, a dry bias across Puerto Rico, and a wet bias on the windward side of mountains within the U.S. Virgin Islands. Despite these biases, model simulations show a robust drying pattern for all islands that is generally larger for Puerto Rico (25% annual rainfall reduction for some life zones) than the U.S. Virgin Islands (12% island average). The largest precipitation reductions are found during the more convectively active afternoon and evening hours. Within Puerto Rico, the model uncertainty increases for the wetter life zones, especially for precipitation. Across the life zones, both models project unprecedented maximum and minimum temperatures that may exceed 200 days annually above the historical baseline with only small changes to the frequency of extreme rainfall. By contrast, in the U.S. Virgin Islands, there is no consensus on the location of the largest drying relative to the windward and leeward side of the islands. However, the models project the largest increases in maximum temperature on the southern side of St. Croix and in higher elevations of St. Thomas and St. John.

4.
Front Plant Sci ; 11: 1174, 2020.
Article in English | MEDLINE | ID: mdl-32849728

ABSTRACT

A warming Arctic has been associated with increases in aboveground plant biomass, specifically shrubs, and changes in vegetation cover. However, the magnitude and direction of changes in NDVI have not been consistent across different tundra types. Here we examine the responsiveness of fine-scale NDVI values to experimental warming at eight sites in northern Alaska, United States. Warming in our eight sites ranged in duration from 2­23 seasons. Dry, wet and moist tundra communities were monitored for canopy surface temperatures and NDVI in ambient and experimentally-warmed plots at near-daily frequencies during the summer of 2017 to assess the impact of the warming treatment on the magnitude and timing of greening. Experimental warming increased canopy-level surface temperatures across all sites (+0.47 to +3.14˚C), with the strongest warming effect occurring during June and July and for the southernmost sites. Green-up was accelerated by warming at six sites, and autumn senescence was delayed at five sites. Warming increased the magnitude of peak NDVI values at five sites, decreased it at one site, and at two sites it did not change. Warming resulted in earlier peak NDVI at three sites and no significant change in the other sites. Shrub and graminoid cover was positively correlated with the magnitude of peak NDVI (r=0.37 to 0.60) while cryptogam influence was mixed. The magnitude and timing of peak NDVI showed considerable variability across sites. Warming extended the duration of the summer green season at most sites due to accelerated greening in the spring and delayed senescence in the autumn. We show that in a warmer Arctic (as simulated by our experiment) the timing and total period of carbon gain may change. Our results suggest these changes are dependent on community composition and abundance of specific growth forms and therefore will likely impact net primary productivity and trophic interactions.

5.
Ecol Appl ; 29(1): e01825, 2019 01.
Article in English | MEDLINE | ID: mdl-30403314

ABSTRACT

Discerning the determinants of species occurrence across landscapes is fundamental to their conservation and management. In spatially and climatologically complex landscapes, explaining the dynamics of occurrence can lead to improved understanding of short- vs. long-term trends and offer novel insight on local vs. regional change. We examined the changes in occupancy for two species of anurans with different life histories over a decade using hundreds of wetland sites in Yellowstone and Grand Teton National Parks. To account for the joint dynamics of wetland drying and amphibian breeding, we adopted a multistate occupancy model as a means to investigate mechanistic relationships of observed occurrence patterns with climatological drivers of wetland hydrologic variability. This approach allowed us to decompose occupancy dynamics into habitat changes caused by wetland drying and amphibian breeding activity, conditional on available water and previous breeding state. Over our 10-yr time series, we observed considerable variability in climate drivers and the proportion of dry wetlands. Boreal chorus frogs (Pseudacris maculata) were more responsive to changes in wetland inundation status than Columbia spotted frogs (Rana luteiventris), as indicated by higher breeding colonization probabilities under favorable (wet) conditions. Both species had high probabilities of breeding persistence in permanently inundated wetlands with prior breeding. Despite the absence of multi-year drought in our time series, mechanistic relationships described here offer insights on how future climate variation may result in reduced and/or shifted occurrence patterns for pond-breeding anurans in the Greater Yellowstone Area. Further, our modeling approach may prove valuable in evaluating determinants of occurrence for other species that are dependent on wetlands or other dynamic habitats.


Subject(s)
Conservation of Natural Resources , Wetlands , Animals , Anura , Breeding , Ecosystem
6.
Ambio ; 46(Suppl 1): 160-173, 2017 Feb.
Article in English | MEDLINE | ID: mdl-28116685

ABSTRACT

Long-term measurements of ecological effects of warming are often not statistically significant because of annual variability or signal noise. These are reduced in indicators that filter or reduce the noise around the signal and allow effects of climate warming to emerge. In this way, certain indicators act as medium pass filters integrating the signal over years-to-decades. In the Alaskan Arctic, the 25-year record of warming of air temperature revealed no significant trend, yet environmental and ecological changes prove that warming is affecting the ecosystem. The useful indicators are deep permafrost temperatures, vegetation and shrub biomass, satellite measures of canopy reflectance (NDVI), and chemical measures of soil weathering. In contrast, the 18-year record in the Greenland Arctic revealed an extremely high summer air-warming of 1.3 °C/decade; the cover of some plant species increased while the cover of others decreased. Useful indicators of change are NDVI and the active layer thickness.


Subject(s)
Climate Change , Ecosystem , Alaska , Arctic Regions , Biodiversity , Biomass , Ecological Parameter Monitoring , Greenland , Plant Physiological Phenomena , Population Density , Population Dynamics , Temperature
7.
Child Abuse Negl ; 53: 40-50, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26704299

ABSTRACT

In October 2012, first 5 LA funded a unique collaboration between Los Angeles County Department of Mental Health (DMH) and UC Davis PCIT Training Center (UCD PCIT) to train county-contracted agencies to provide Parent-Child Interaction Therapy (PCIT). This $20 million dollar, 5-year grant represented the largest implementation effort of an empirically based treatment to date. The purpose of this paper was to describe the first 2 years of the implementation process of this project, beginning with project start up and pre-implementation phases, and to present agency training and client performance outcomes from our first year of training. Results presented in this evaluation suggest that it is possible to train LA County providers in PCIT, and that PCIT is an effective intervention for DMH-contracted providers in LA County. This evaluation also discusses challenges to successful implementation. Barriers to progress included unanticipated delays building county infrastructure, trainee attrition, and insufficient client referrals. We discuss the results of the current implementation with respect to theory, research, and others' training models, with the aim of evaluating and prioritizing different implementation drivers, noting the ongoing competition between knowing what to do and the need for action.


Subject(s)
Child Protective Services/education , Health Personnel/education , Parent-Child Relations , Psychotherapy/education , Attention Deficit and Disruptive Behavior Disorders/rehabilitation , Child , Child Protective Services/organization & administration , Child, Preschool , Evidence-Based Practice/education , Evidence-Based Practice/organization & administration , Health Plan Implementation/organization & administration , Humans , Inservice Training/organization & administration , Los Angeles , Mental Health/education , Mental Health Services/organization & administration , Parenting , Program Evaluation , Training Support
8.
Proc Natl Acad Sci U S A ; 112(2): 448-52, 2015 Jan 13.
Article in English | MEDLINE | ID: mdl-25548195

ABSTRACT

Inference about future climate change impacts typically relies on one of three approaches: manipulative experiments, historical comparisons (broadly defined to include monitoring the response to ambient climate fluctuations using repeat sampling of plots, dendroecology, and paleoecology techniques), and space-for-time substitutions derived from sampling along environmental gradients. Potential limitations of all three approaches are recognized. Here we address the congruence among these three main approaches by comparing the degree to which tundra plant community composition changes (i) in response to in situ experimental warming, (ii) with interannual variability in summer temperature within sites, and (iii) over spatial gradients in summer temperature. We analyzed changes in plant community composition from repeat sampling (85 plant communities in 28 regions) and experimental warming studies (28 experiments in 14 regions) throughout arctic and alpine North America and Europe. Increases in the relative abundance of species with a warmer thermal niche were observed in response to warmer summer temperatures using all three methods; however, effect sizes were greater over broad-scale spatial gradients relative to either temporal variability in summer temperature within a site or summer temperature increases induced by experimental warming. The effect sizes for change over time within a site and with experimental warming were nearly identical. These results support the view that inferences based on space-for-time substitution overestimate the magnitude of responses to contemporary climate warming, because spatial gradients reflect long-term processes. In contrast, in situ experimental warming and monitoring approaches yield consistent estimates of the magnitude of response of plant communities to climate warming.


Subject(s)
Climate Change , Ecological Parameter Monitoring/methods , Plants , Biodiversity , Ecosystem , Global Warming , Plant Physiological Phenomena
9.
PLoS One ; 9(10): e108739, 2014.
Article in English | MEDLINE | ID: mdl-25310800

ABSTRACT

The northern salt marsh harvest mouse (Reithrodontomys raviventris halicoetes) is an endangered species endemic to the San Francisco Bay Estuary. Using a conservation behavior perspective, we examined how salt marsh harvest mice cope with both natural (daily tidal fluctuations) and anthropogenic (modification of tidal regime) changes in natural tidal wetlands and human-created diked wetlands, and investigated the role of behavioral flexibility in utilizing a human-created environment in the Suisun Marsh. We used radio telemetry to determine refuge use at high tide, space use, and movement rates to investigate possible differences in movement behavior in tidal versus diked wetlands. We found that the vast majority of the time salt marsh harvest mice remain in vegetation above the water during high tides. We also found no difference in space used by mice during high tide as compared to before or after high tide in either tidal or diked wetlands. We found no detectable difference in diurnal or nocturnal movement rates in tidal wetlands. However, we did find that diurnal movement rates for mice in diked wetlands were lower than nocturnal movement rates, especially during the new moon. This change in movement behavior in a relatively novel human-created habitat indicates that behavioral flexibility may facilitate the use of human-created environments by salt marsh harvest mice.


Subject(s)
Conservation of Natural Resources , Ecosystem , Endangered Species , Wetlands , Animals , Humans , Mice , Movement
10.
Ecol Lett ; 15(2): 164-75, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22136670

ABSTRACT

Understanding the sensitivity of tundra vegetation to climate warming is critical to forecasting future biodiversity and vegetation feedbacks to climate. In situ warming experiments accelerate climate change on a small scale to forecast responses of local plant communities. Limitations of this approach include the apparent site-specificity of results and uncertainty about the power of short-term studies to anticipate longer term change. We address these issues with a synthesis of 61 experimental warming studies, of up to 20 years duration, in tundra sites worldwide. The response of plant groups to warming often differed with ambient summer temperature, soil moisture and experimental duration. Shrubs increased with warming only where ambient temperature was high, whereas graminoids increased primarily in the coldest study sites. Linear increases in effect size over time were frequently observed. There was little indication of saturating or accelerating effects, as would be predicted if negative or positive vegetation feedbacks were common. These results indicate that tundra vegetation exhibits strong regional variation in response to warming, and that in vulnerable regions, cumulative effects of long-term warming on tundra vegetation - and associated ecosystem consequences - have the potential to be much greater than we have observed to date.


Subject(s)
Adaptation, Biological , Ecosystem , Global Warming , Plant Development , Arctic Regions , Biodiversity , Models, Biological
11.
College Station; Stata Press; 3rd ed; 2010. 412 p.
Monography in English | LILACS | ID: lil-766634
12.
College Station; Stata Press; 3rd ed; 2010. 412 p.
Monography in English | LILACS, Coleciona SUS | ID: biblio-941648
13.
Rev. biol. trop ; 56(2): 625-639, jun. 2008. ilus, tab
Article in English | LILACS | ID: lil-637665

ABSTRACT

Assessing the status of tropical dry forest habitats using remote sensing technologies is one of the research priorities for Neotropical forests. We developed a simple method for mapping vegetation and habitats in a tropical dry forest reserve, Mona Island, Puerto Rico, by integrating the Normalized Difference vegetation Index (NDvI) from Landsat, topographic information, and high-resolution Ikonos imagery. The method was practical for identifying vegetation types in areas with a great variety of plant communities and complex relief, and can be adapted to other dry forest habitats of the Caribbean Islands. NDvI was useful for identifying the distribution of forests, woodlands, and shrubland, providing a natural representation of the vegetation patterns on the island. The use of Ikonos imagery allowed increasing the number of land cover classes. As a result, sixteen land-cover types were mapped over the 5 500 ha area, with a kappa coefficient of accuracy equal to 79 %. This map is a central piece for modeling vertebrate species distribution and biodiversity patterns by the Puerto Rico Gap Analysis Project, and it is of great value for assisting research and management actions in the island. Rev. Biol. Trop. 56 (2): 625-639. Epub 2008 June 30.


El estudio y evaluación de los bosques tropicales secos mediante herramientas de teledetección es una de las prioridades de investigación en los ambientes neotropicales. Desarrollamos una metodología simple para mapear la vegetación de la isla de Mona, Puerto Rico, mediante el uso del índice de vegetación normalizado (NDVI por sus siglas en inglés) de Landsat, información topográfica, e imágenes auxiliares de alta resolución Ikonos. La metodología fue útil para identificar las clases de vegetación en un área de gran variedad de comunidades vegetales y relieve complejo, y puede ser adaptada a otras regiones de bosque seco de las islas del Caribe. El NDVI permitió identificar la distribución de los bosques cerrados, abiertos, y arbustos, proveyendo una representación natural de los patrones de vegetación en la isla. Las imágenes de Ikonos permitieron incrementar el número de clases detectadas. Como resultado, mapeamos 16 clases de cobertura del terreno en las 5 500 hectáreas de la isla de Mona, con un coeficiente de concordancia kappa de un 79%. La información obtenida en este estudio será utilizada para modelar la distribución de los vertebrados terrestres y patrones de biodiversidad en la isla, como parte del proyecto Gap Análisis de Puerto Rico, y es de gran valor para asistir en las actividades de investigación y manejo en la isla.


Subject(s)
Environmental Monitoring/methods , Geographic Information Systems , Trees/physiology , Population Dynamics , Puerto Rico , Satellite Communications , Tropical Climate , Trees/classification
14.
Ambio ; 37(7-8): 521, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19205172
15.
Ambio ; 37(7-8): 563-8, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19205179

ABSTRACT

Methods for evaluating the impact of fires within tropical forests are needed as fires become more frequent and human populations and demands on forests increase. Short- and long-term fire effects on soils are determined by the prefire, fire, and postfire environments. We placed these components within a fire-disturbance continuum to guide our literature synthesis and develop an integrated soil burn severity index. The soil burn severity index provides a set of indicators that reflect the range of conditions present after a fire. The index consists of seven levels, an unburned level and six other levels that describe a range of postfire soil conditions. We view this index as a tool for understanding the effects of fires on the forest floor, with the realization that as new information is gained, the index may be modified as warranted.


Subject(s)
Ecosystem , Fires , Soil , Trees , Conservation of Natural Resources , Models, Biological , Tropical Climate
16.
Ambio ; 37(7-8): 569-76, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19205180

ABSTRACT

An increased ability to analyze landscapes in a spatial manner through the use of remote sensing leads to improved capabilities for quantifying human-induced forest fragmentation. Developments of spatially explicit methods in landscape analyses are emerging. In this paper, the image delineation software program eCognition and the spatial pattern analysis program FRAGSTATS were used to quantify patterns of forest fragments on six landscapes across three different climatic regions characterized by different moisture regimes and different influences of human pressure. Our results support the idea that landscapes with higher road and population density are more fragmented; however, there are other, equally influential factors contributing to fragmentation, such as moisture regime, historic land use, and fire dynamics. Our method provided an objective means to characterize landscapes and assess patterns of forest fragments across different forested ecosystems by addressing the limitations of pixel-based classification and incorporating image objects.


Subject(s)
Ecosystem , Geographic Information Systems , Models, Biological , Trees , Caribbean Region , Geography , Humans , Image Processing, Computer-Assisted , North America , Population Density , Satellite Communications , Tropical Climate
17.
Ambio ; 37(7-8): 577-87, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19205181

ABSTRACT

Forest fragmentation affects the heterogeneity of accumulated fuels by increasing the diversity of forest types and by increasing forest edges. This heterogeneity has implications in how we manage fuels, fire, and forests. Understanding the relative importance of fragmentation on woody biomass within a single climatic regime, and along climatic gradients, will improve our ability to manage forest fuels and predict fire behavior. In this study we assessed forest fuel characteristics in stands of differing moisture, i.e., dry and moist forests, structure, i.e., open canopy (typically younger) vs. closed canopy (typically older) stands, and size, i.e., small (10-14 ha), medium (33 to 60 ha), and large (100-240 ha) along a climatic gradient of boreal, temperate, and tropical forests. We measured duff, litter, fine and coarse woody debris, standing dead, and live biomass in a series of plots along a transect from outside the forest edge to the fragment interior. The goal was to determine how forest structure and fuel characteristics varied along this transect and whether this variation differed with temperature, moisture, structure, and fragment size. We found nonlinear relationships of coarse woody debris, fine woody debris, standing dead and live tree biomass with mean annual median temperature. Biomass for these variables was greatest in temperate sites. Forest floor fuels (duff and litter) had a linear relationship with temperature and biomass was greatest in boreal sites. In a five-way multivariate analysis of variance we found that temperature, moisture, and age/structure had significant effects on forest floor fuels, downed woody debris, and live tree biomass. Fragment size had an effect on forest floor fuels and live tree biomass. Distance from forest edge had significant effects for only a few subgroups sampled. With some exceptions edges were not distinguishable from interiors in terms of fuels.


Subject(s)
Biomass , Ecosystem , Trees , Conservation of Natural Resources , Fires , North America , Puerto Rico , Regression Analysis , Tropical Climate , Wood
18.
Ambio ; 37(7-8): 588-97, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19205182

ABSTRACT

In this study, we set up a wood decomposition experiment to i) quantify the percent of mass remaining, decay constant and performance strength of aspen stakes (Populus tremuloides) in dry and moist boreal (Alaska and Minnesota, USA), temperate (Washington and Idaho, USA), and tropical (Puerto Rico) forest types, and ii) determine the effects of fragmentation on wood decomposition rates as related to fragment size, forest age (and/or structure) and climate at the macro- and meso-scales. Fragment sizes represented the landscape variability within a climatic region. Overall, the mean small fragments area ranged from 10-14 ha, medium-sized fragments 33 to 60 ha, and large fragments 100-240 ha. We found that: i) aspen stakes decayed fastest in the tropical sites, and the slowest in the temperate forest fragments, ii) the percent of mass remaining was significantly greater in dry than in moist forests in boreal and temperate fragments, while the opposite was true for the tropical forest fragments, iii) no effect of fragment size on the percent of mass remaining of aspen stakes in the boreal sites, temperate dry, and tropical moist forests, and iv) no significant differences of aspen wood decay between forest edges and interior forest in boreal, temperate and tropical fragments. We conclude that: i) moisture condition is an important control over wood decomposition over broad climate gradients; and that such relationship can be non linear, and ii) the presence of a particular group of organism (termites) can significantly alter the decay rates of wood more than what might be predicted based on climatic factors alone. Biotic controls on wood decay might be more important predictors of wood decay in tropical regions, while abiotic constraints seems to be important determinants of decay in cold forested fragments.


Subject(s)
Biomass , Ecosystem , Populus , Wood , Conservation of Natural Resources , Puerto Rico , Trees , Tropical Climate , United States
19.
Rev Biol Trop ; 56(2): 625-39, 2008 Jun.
Article in English | MEDLINE | ID: mdl-19256433

ABSTRACT

Assessing the status of tropical dry forest habitats using remote sensing technologies is one of the research priorities for Neotropical forests. We developed a simple method for mapping vegetation and habitats in a tropical dry forest reserve, Mona Island, Puerto Rico, by integrating the Normalized Difference Vegetation Index (NDVI) from Landsat, topographic information, and high-resolution Ikonos imagery. The method was practical for identifying vegetation types in areas with a great variety of plant communities and complex relief, and can be adapted to other dry forest habitats of the Caribbean Islands. NDVI was useful for identifying the distribution of forests, woodlands, and shrubland, providing a natural representation of the vegetation patterns on the island. The use of Ikonos imagery allowed increasing the number of land cover classes. As a result, sixteen land-cover types were mapped over the 5500 ha area, with a kappa coefficient of accuracy equal to 79%. This map is a central piece for modeling vertebrate species distribution and biodiversity patterns by the Puerto Rico Gap Analysis Project, and it is of great value for assisting research and management actions in the island.


Subject(s)
Environmental Monitoring/methods , Geographic Information Systems , Trees/physiology , Population Dynamics , Puerto Rico , Satellite Communications , Trees/classification , Tropical Climate
20.
Evolution ; 59(9): 2025-32, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16261739

ABSTRACT

The bill structures of different call types of red crossbills (Loxia curvirostra complex) in western North America usually approximate the predicted optima for foraging on single species of conifers. One clear exception is the call type in the South Hills, Idaho, that is coevolving in an evolutionary arms race with Rocky Mountain lodgepole pine (Pinus contorta ssp. latifolia). Although South Hills crossbills forage only on the cones of these lodgepole pines, their average bill depth is smaller than that predicted to be optimal. Because preliminary data showed that large-billed males were more likely to exhibit symptoms of ectoparasitic mite (Knemidokoptes jamaicensis) infestation, the goal of our study was to further quantify the incidence of mite infestation and determine whether selection by mites may have favored smaller-billed crossbills and thus driven crossbills away from the foraging optimum. We estimated annual survival of both infected and uninfected South Hills crossbills using program MARK, which allows for auxiliary variables such as bill size and sex to be included in survival analyses. Mite infestation depressed crossbill survival and, especially for males, caused directional selection against larger-billed individuals. Such selection may explain why South Hills crossbills have smaller bills than the optimum and why average bill size for males has decreased from 1998 to 2003. This selection may also explain why the degree of sexual size dimorphism has decreased by nearly 50% since 1998.


Subject(s)
Adaptation, Biological , Beak/anatomy & histology , Mites/physiology , Passeriformes/anatomy & histology , Passeriformes/parasitology , Selection, Genetic , Symbiosis , Animals , Body Weights and Measures , Idaho , Male , Passeriformes/physiology , Pinus/anatomy & histology , Sex Characteristics , Survival Analysis
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