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Search Results: 1 - 10 of 119677 matches for " T. Mitchell Aide "
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Virtual Interpretation of Earth Web-Interface Tool (VIEW-IT) for Collecting Land-Use/Land-Cover Reference Data
Matthew L. Clark,T. Mitchell Aide
Remote Sensing , 2011, DOI: 10.3390/rs3030601
Abstract: Web-based applications that integrate geospatial information, or the geoweb, offer exciting opportunities for remote sensing science. One such application is a Web?based system for automating the collection of reference data for producing and verifying the accuracy of land-use/land-cover (LULC) maps derived from satellite imagery. Here we describe the capabilities and technical components of the Virtual Interpretation of Earth Web-Interface Tool (VIEW-IT), a collaborative browser-based tool for “crowdsourcing” interpretation of reference data from high resolution imagery. The principal component of VIEW-IT is the Google Earth plug-in, which allows users to visually estimate percent cover of seven basic LULC classes within a sample grid. The current system provides a 250 m square sample to match the resolution of MODIS satellite data, although other scales could be easily accommodated. Using VIEW-IT, a team of 23?student and 7 expert interpreters collected over 46,000 reference samples across Latin America and the Caribbean. Samples covered all biomes, avoided spatial autocorrelation, and spanned years 2000 to 2010. By embedding Google Earth within a Web-based application with an intuitive user interface, basic interpretation criteria, distributed Internet access, server-side storage, and automated error-checking, VIEW-IT provides a time and cost efficient means of collecting a large dataset of samples across space and time. When matched with predictor variables from satellite imagery, these data can provide robust mapping algorithm calibration and accuracy assessment. This development is particularly important for regional to global scale LULC mapping efforts, which have traditionally relied on sparse sampling of medium resolution imagery and products for reference data. Our ultimate goal is to make VIEW-IT available to all users to promote rigorous, global land-change monitoring.
Effects of habitat and landscape characteristics on medium and large mammal species richness and composition in northern Uruguay
Andrade-Nú?ez, María José;Aide, T. Mitchell;
Zoologia (Curitiba) , 2010, DOI: 10.1590/S1984-46702010000600012
Abstract: the increasing world population and demand for food and other products has accelerated the conversion of natural habitats into agricultural lands, plantations and urban areas. changes in habitat and landscape characteristics due to land-use change can have a significant effect on species presence, abundance, and distribution. multi-scale approaches have been used to determine the proper spatial scales at which species and communities are responding to habitat transformation. in this context, we evaluated medium and large mammal species richness and composition in gallery forest (n = 10), grassland (n = 10), and exotic tree plantation (n = 10) in a region where grasslands have been converted into exotic tree plantations. we quantified mammal species richness and composition with camera traps and track surveys. the composition of the mammal community was related with local habitat variables, and landscape variables measured at seven spatial scales. we found 14 mammal species in forest, 11 species in plantation, and 7 mammal species in grassland. two species are exotics, the wild boar sus scrofa linnaeus, 1758 and the european hare lepus europaeus pallas, 1778. the most common species are the crab-eating fox cerdocyon thous linnaeus, 1766, the nine-banded armadillo dasypus novemcinctus linnaeus, 1758 and the gray brocket deer mazama gouazoubira g. fischer, 1814 which are generalist species. our results showed significant differences in mammal species richness and composition among the three habitat types. plantations can have positive and negative effects on the presence of species restricted to grasslands. positive effects are reflected in a wider local distribution of some forest species that rarely use grassland. the most important habitat and landscape variables that influenced mammal species richness and composition were vertical structure index, canopy cover, tree species diversity, percentage of grass, and the percentage of forest and grassland at the landscape
Thirty Years of Human Demography and Land-Use Change in the Atlantic Forest of Misiones, Argentina: an Evaluation of the Forest Transition Model
Andrea E. Izquierdo,Carlos D. De Angelo,T. Mitchell. Aide
Ecology and Society , 2008,
Abstract: For many years, tropical and subtropical forests have been deforested for agriculture, grazing, and timber extraction. Nevertheless in the last decade, several publications have suggested that some regions of Latin America are showing a process of forest transition. Forest transition theory predicts that industrialization and urbanization will lead to the abandonment of marginal agriculture lands and the recovery of natural systems such as forests. However, there are many ecological, economic, and social factors that could act as barriers to ecosystem recovery. To evaluate this hypothesis, we analyzed the socioeconomic and land-use changes during the last 30 years at the provincial and departmental level in the province of Misiones, Argentina. We described the changes in the distribution of urban and rural populations based on national population censuses from 1970, 1980, 1991, and 2001. Land-use change was based on a supervised analysis of four mosaics of Landsat Multispectral Scanner and Thematic Mapper satellite images from 1973, 1979, 1987/1989, and 2006. Although the change in the rural population varied greatly among the departments, there has been a dramatic increase in the urban population at the provincial level. The major land-use changes between 1973 and 2006 were an increase in monospecific plantations of mainly Pinus and Eucalyptus of 2702 km2 and a loss of 4689 km2 of natural forest. Misiones possesses the largest remnant of continuous Atlantic Forest, which is famous for its high level of biodiversity and endemism, but much of this forest now comprises monospecific plantations. Although demographic changes in Misiones are similar to those that have occurred other regions (i.e., rural–urban migration), and the increase in forest plantations helps to maintain forest cover, this cover has much lower ecological value than that of natural forest. To ensure the conservation of the high-diversity Atlantic Forest in Misiones requires a better effort to understand the interactions among the diverse factors that affect land-use patterns in this region.
Land Cover Change in Colombia: Surprising Forest Recovery Trends between 2001 and 2010
Ana María Sánchez-Cuervo, T. Mitchell Aide, Matthew L. Clark, Andrés Etter
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0043943
Abstract: Background Monitoring land change at multiple spatial scales is essential for identifying hotspots of change, and for developing and implementing policies for conserving biodiversity and habitats. In the high diversity country of Colombia, these types of analyses are difficult because there is no consistent wall-to-wall, multi-temporal dataset for land-use and land-cover change. Methodology/Principal Findings To address this problem, we mapped annual land-use and land-cover from 2001 to 2010 in Colombia using MODIS (250 m) products coupled with reference data from high spatial resolution imagery (QuickBird) in Google Earth. We used QuickBird imagery to visually interpret percent cover of eight land cover classes used for classifier training and accuracy assessment. Based on these maps we evaluated land cover change at four spatial scales country, biome, ecoregion, and municipality. Of the 1,117 municipalities, 820 had a net gain in woody vegetation (28,092 km2) while 264 had a net loss (11,129 km2), which resulted in a net gain of 16,963 km2 in woody vegetation at the national scale. Woody regrowth mainly occurred in areas previously classified as mixed woody/plantation rather than agriculture/herbaceous. The majority of this gain occurred in the Moist Forest biome, within the montane forest ecoregions, while the greatest loss of woody vegetation occurred in the Llanos and Apure-Villavicencio ecoregions. Conclusions The unexpected forest recovery trend, particularly in the Andes, provides an opportunity to expand current protected areas and to promote habitat connectivity. Furthermore, ecoregions with intense land conversion (e.g. Northern Andean Páramo) and ecoregions under-represented in the protected area network (e.g. Llanos, Apure-Villavicencio Dry forest, and Magdalena-Urabá Moist forest ecoregions) should be considered for new protected areas.
Real-time bioacoustics monitoring and automated species identification
T. Mitchell Aide,Carlos Corrada-Bravo,Marconi Campos-Cerqueira,Carlos Milan
PeerJ , 2013, DOI: 10.7717/peerj.103
Abstract: Traditionally, animal species diversity and abundance is assessed using a variety of methods that are generally costly, limited in space and time, and most importantly, they rarely include a permanent record. Given the urgency of climate change and the loss of habitat, it is vital that we use new technologies to improve and expand global biodiversity monitoring to thousands of sites around the world. In this article, we describe the acoustical component of the Automated Remote Biodiversity Monitoring Network (ARBIMON), a novel combination of hardware and software for automating data acquisition, data management, and species identification based on audio recordings. The major components of the cyberinfrastructure include: a solar powered remote monitoring station that sends 1-min recordings every 10 min to a base station, which relays the recordings in real-time to the project server, where the recordings are processed and uploaded to the project website (arbimon.net). Along with a module for viewing, listening, and annotating recordings, the website includes a species identification interface to help users create machine learning algorithms to automate species identification. To demonstrate the system we present data on the vocal activity patterns of birds, frogs, insects, and mammals from Puerto Rico and Costa Rica.
Agricultural Abandonment, Suburban Growth, and Forest Expansion in Puerto Rico between 1991 and 2000
Isabel K. Parés-Ramos,William A. Gould,T. Mitchell. Aide
Ecology and Society , 2008,
Abstract: The response of local economies to the globalization process can have a large effect on population and land-use dynamics. In countries with a high population density and relatively high levels of education, the globalization process has resulted in a shift in the local economy from agriculture to manufacturing, technology, and service sectors. This shift in the economy has impacted land-use dynamics by decreasing agricultural lands, increasing urban growth, and in some cases, increasing forest cover. This process of economic and forest transition has been well documented in Puerto Rico for the period 1950 to 1990, but some authors predicted that poor planning and continued urban growth would eliminate the gains in forest cover. To investigate the impacts of recent economic changes, we evaluated demographic and land-use changes for 880 “barrios” (i.e., neighborhoods), the smallest administrative unit, in Puerto Rico using government census data from 1990 and 2000 and land-cover classifications from 1991 and 2000. During this period, the population increased by 284 127 people (8.2%). Most of the growth was in the suburban barrios, whereas urban barrios lost population. This shift was reflected by the construction of more than 100 000 housing units in suburban barrios. Although urban sprawl is perceived as the major land-cover change, urban cover only increased from 10% to 11% between 1990 and 2000, whereas the increase in forest cover was much greater (28% to 40%). Grasslands and shrublands were the major sources of new urban and forest areas in 2000. Although these results are encouraging in terms of increasing forest cover, most of the new development has been concentrated in the coastal plains, which are the location of most of the remaining agricultural areas, a few protected areas, and threatened ecosystems (e.g., mangroves).
Mapping Urbanization Dynamics in Major Cities of Colombia, Ecuador, Perú, and Bolivia Using Night-Time Satellite Imagery
Isabel K. Parés-Ramos,Nora L. álvarez-Berríos,T. Mitchell Aide
Land , 2013, DOI: 10.3390/land2010037
Abstract: By 2050, 90% of the population in Latin America will live in cities, but there is a lack of up-to-date spatial information about the urban extent and patterns of urbanization in cities of this region. In this study, we analyzed population growth, urban density and urbanization dynamics between 1992 and 2009 in the major cities of Bolivia, Colombia, Ecuador and Perú using Google Earth and DMSP/OLS night-time lights imagery. We used Google Earth to map the urban extent, and time series of night-time lights to analyze spatial patterns of urban development. The dominant urban development patterns were: high-density compact in Bogotá, Cali, Guayaquil, and Medellín; high-density expansive growth in La Paz/El Alto; low-density expansive in Quito and Santa Cruz; and a mix of high-density compact and suburban growth in Lima. Urban growth occurred largely along the periphery of cities, influenced by the local landscape and by demographic and socioeconomic factors such as immigration and housing prices. Urban density in Colombia (>20,000 per/km 2) was among the highest in the world. Future growth in the region will probably be characterized by densification and slow urban expansion. This study also validates the utility of Google Earth and night-time lights for monitoring urbanization.
Land Change in the Greater Antilles between 2001 and 2010
Nora L. álvarez-Berríos,Daniel J. Redo,T. Mitchell Aide,Matthew L. Clark,Ricardo Grau
Land , 2013, DOI: 10.3390/land2020081
Abstract: Land change in the Greater Antilles differs markedly among countries because of varying socioeconomic histories and global influences. We assessed land change between 2001 and 2010 in municipalities (second administrative units) of Cuba, Dominican Republic, Haiti, Jamaica, and Puerto Rico. Our analysis used annual land-use/land-cover maps derived from MODIS satellite imagery to model linear change in woody vegetation, mixed-woody/plantations and agriculture/herbaceous vegetation. Using this approach, we focused on municipalities with significant change ( p ≤ 0.05). Between 2001 and 2010, the Greater Antilles gained 801 km 2 of woody vegetation. This increase was mainly due to the return of woody vegetation in Cuba, and smaller increases in Puerto Rico and the Dominican Republic. Despite relatively similar environments, the factors associated with these changes varied greatly between countries. In Puerto Rico, Dominican Republic, and Jamaica, agriculture declined while mixed-woody vegetation increased, mostly in montane regions. In contrast, Cuba experienced an extensive decline in sugarcane plantations, which resulted in the spread of an invasive woody shrub species and the increase in woody vegetation in areas of high agricultural value. In Haiti, the growing population, fuelwood consumption, and increase in agriculture contributed to woody vegetation loss; however, woody vegetation loss was accompanied with a significant increase in the mixed woody and plantations class. Most regional analyses often treated the Greater Antilles as a homogeneous unit; our results suggest that historical and socio-economic differences among countries are crucial for understanding the variation in present day land change dynamics.
Rare Earth Elements: Their Importance in Understanding Soil Genesis
Michael T. Aide,Christine Aide
ISRN Soil Science , 2012, DOI: 10.5402/2012/783876
Abstract:
Globalization and Land-Use Transitions in Latin America
H. Ricardo. Grau,Mitchell Aide
Ecology and Society , 2008,
Abstract: Current socioeconomic drivers of land-use change associated with globalization are producing two contrasting land-use trends in Latin America. Increasing global food demand (particularly in Southeast Asia) accelerates deforestation in areas suitable for modern agriculture (e.g., soybean), severely threatening ecosystems, such as Amazonian rain forests, dry forests, and subtropical grasslands. Additionally, in the coming decades, demand for biofuels may become an emerging threat. In contrast, high yields in modern agricultural systems and rural–urban migration coupled with remittances promote the abandonment of marginal agricultural lands, thus favoring ecosystem recovery on mountains, deserts, and areas of poor soils, while improving human well-being. The potential switch from production in traditional extensive grazing areas to intensive modern agriculture provides opportunities to significantly increase food production while sparing land for nature conservation. This combination of emerging threats and opportunities requires changes in the way the conservation of Latin American ecosystems is approached. Land-use efficiency should be analyzed beyond the local-based paradigm that drives most conservation programs, and focus on large geographic scales involving long-distance fluxes of products, information, and people in order to maximize both agricultural production and the conservation of environmental services.
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