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13 resultados encontrados para: AUTOR: Schneider, Laura C
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Resumen en: Inglés |
Resumen en inglés

Land system science axiomatically addresses social–environmental systems by integrating the dynamics of land uses (social) and land covers (environment), invariably including the use of remote sensing data and often, spatially explicit models of land change. This kind of research is illustrated through the Southern Yucatán Peninsular Region project (1997–2008) aimed at understanding, predicting, and projecting spatially explicit land change in a region with juxtaposed land uses-agriculture and a biosphere reserve. The successes of the project, its contributions to contemporary land system science, and the organizational mechanisms that fostered the research are identified as well as various corrections, which if applied, may have refined and extended the project's goals. Overall, the project demonstrates the kind of integrated research required to advance understanding of a social-environment system and the team-based methods used in the process.


2.
- Capítulo de libro con arbitraje
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Precipitation variability and adaptation strategies in the southern Yucatán Peninsula, Mexico: integrating local knowledge with quantitative analysis
Márdero Jiménez, Silvia Sofía ; Schmook, Birgit Inge (coaut.) ; Christman, Zachary John (coaut.) ; Nickl Alcocer, Elsa Cristina (coaut.) ; Schneider, Laura (coaut.) ; Rogan, John (coaut.) ; Lawrence, Deborah (coaut.) ;
Contenido en: International Perspectives on Climate Change Switzerland, German : Springer International Publishing, 2014 p. 189-201 ISBN:978-331-9044-88-0
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Resumen en: Inglés |
Resumen en inglés

Climatic variability, including droughts, has long affected the Mayan Lowlands. Therefore, farmers have developed coping strategies to mitigate these impacts. In the past, however, records of these effects and responses were largely anecdotal. In modern times, the perceptions of farmers, especially those practicing rain-fed agriculture, combined with the increased availability of accurate historical climatic records and forecasts, can provide useful information regarding periods of decreased precipitation and strategies employed to resist and respond to drought effects. As part of the multidisciplinary and inter-institutional project, New Knowledge about Ecosystem Level Response to Increased Frequency of Large-Scale Natural Disturbance Driven by Climate Change, this chapter outlines the spatial and temporal variability of precipitation across the Southern Yucatán Peninsula, Mexico, and examines Mayan farmers’ adaptations to droughts and other climate perturbations. The authors analyzed precipitation trends and anomalies from 1953 to 2007, using linear regressions and the quintile method to classify meteorological droughts. Authors also conducted 150 household interviews across 10 communities to investigate Mayan farmers’ adaptations to climate perturbations.

Results demonstrate a significant decrease in annual and rainy season precipitation across much of the study area, coupled with an increased occurrence of droughts, especially since 1980. Interviewed subsistence maize farmers have adapted to decreasing and irregular precipitation by adjusting agricultural calendars, planting more maize varieties, increasing water storage, and diversifying their practices both within the agricultural system and beyond it. Through this research, the authors demonstrate the importance of incorporating farmers’ local and traditional knowledge into prevention and mitigation policies of governmental and non-governmental institutions in the region.


3.
- Artículo con arbitraje
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Damage patterns after Hurricane Dean in the southern Yucatán: has human activity resulted in more resilient forests?
McGroddy, Megan ; Lawrence, Deborah (coaut.) ; Schneider, Laura C. (autora) ; Rogan, John (autor) ; Zager, Irene (autora) ; Schmook, Birgit Inge (autora) ;
Disponible en línea
Contenido en: Forest Ecology and Management Vol. 310, (December 2013), p. 812–820 ISSN: 0378-1127
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Resumen en: Inglés |
Resumen en inglés

We investigated how patterns of hurricane damage were related to windspeed, stand characteristics, and land use in a region where forest composition and structure have been strongly influenced by human activities. In 2007 Hurricane Dean hit the biological corridor between the two largest biosphere reserves on the Yucatán Peninsula as a category 5 hurricane. Land use in the corridor has altered both landscape and forest stand structure. Compared to the upland protected areas, forests in the study area were significantly shorter and characterized by smaller stems. Nine months after the hurricane we assessed the damage in a set of 91 plots to test the effect of local stand structure on hurricane resistance. For each 5 × 100 m plot, we calculated the proportion of both stems and basal area damaged using 7 classes (no damage, small branch, major branch, stem bent, stem snapped, tree uprooted and tree death). Interviews with land- owners provided recent land use histories for the past 30 years for most study plots. For the two dominant forest types analysis of variance found that canopy height, median dbh and basal area all varied significantly with land use history and forest type. We tested the effect of median stem diameter, canopy height, stem density, basal area and tree species density on damage. Despite the strength of the storm, on average 27% of stems at the stand level showed no signs of damage and only 5% across the study were killed by the hurricane. In step-wise linear regression models, 13–52% of the variation in damage frequency was accounted for by windspeed and stand structure. Canopy height, basal area and median dbh were significant predictors. For moderate to severe damage classes, measures of stand size were generally positively correlated with damage frequency suggesting that stands with higher canopies and/or greater basal area or median dbh suffered the most during this storm event.


4.
- Artículo de divulgación
*En hemeroteca, SIBE-Campeche, SIBE-Chetumal, SIBE-San Cristóbal, SIBE-Tapachula, SIBE-Villahermosa
Helechos: malhechos en sistemas agrícolas
Schneider, Laura C. ;
Contenido en: ECOFronteras No. 47 (enero-abril 2013), p. 4-6
Cerrar
SIBE Campeche
52364-50 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Chetumal
52364-40 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE San Cristóbal
52364-10 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Tapachula
52364-30 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Villahermosa
52364-20 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-Campeche, SIBE-Chetumal, SIBE-San Cristóbal, SIBE-Tapachula, SIBE-Villahermosa
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5.
- Artículo con arbitraje
Resumen en: Inglés |
Resumen en inglés

This research examines the spatio-temporal trends in Advanced Very High Resolution Radiometer (AVHRR) Global Inventory Modelling and Mapping Studies (GIMMS) normalized difference vegetation index (NDVI) time series to ascribe land use change and precipitation to observed changes in land cover from 1982 to 2007 in the Mexican Yucatán Peninsula, using seasonal trend analysis (STA). In addition to discrete land cover transitions across the study region, patterns of agricultural intensification, urban expansion and afforestation in protected areas have enacted changes to the seasonal patterns of apparent greenness observed through STA greenness parameters. The results indicate that the seasonal variation in NDVI can be used to distinguish among different land cover transitions, and the primary differences among these transitions were in changes in overall greenness, peak annual greenness and the timing of the growing season. Associations between greenness trends and precipitation were weak, indicating a human-dominated system for the 26 years examined. Changes in the states of Campeche, Quintana Roo and Yucatán appear to be associated with pasture cultivation, urban expansion-extensive cultivation and urban expansion-intensive cultivation, respectively.


6.
- Artículo con arbitraje
*En hemeroteca, SIBE-Campeche, SIBE-San Cristóbal, SIBE-Villahermosa, SIBE-Tapachula
Sequías en el sur de la Península de Yucatán: análisis de la variabilidad anual y estacional de la precipitación
Márdero Jiménez, Silvia Sofía ; Nickl Alcocer, Elsa Cristina (coaut.) ; Schmook, Birgit Inge (coaut.) ; Schneider, Laura C. (coaut.) ; Rogan, John (coaut.) ; Christman, Zachary John (coaut.) ; Lawrence, Deborah (coaut.) ;
Contenido en: Investigaciones Geográficas No. 78 (2012), p. 19-33 ISSN: 0188-4611
Cerrar
SIBE Campeche
40003-30 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE San Cristóbal
40003-20 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Tapachula
40003-50 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Villahermosa
40003-40 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-Campeche, SIBE-San Cristóbal, SIBE-Villahermosa, SIBE-Tapachula
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Resumen en: Español | Inglés |
Resumen en español

Este estudio analiza la variabilidad espacial y temporal de la precipitación en el sur de la península de Yucatán, a través de anomalías y tendencias de la precipitación anual y estacional y la ocurrencia de sequías meteorológicas, empleando datos de lluvia de nueve estaciones meteorológicas para el periodo de 1953-2007. Utilizando tendencias de regresión lineal anuales y estacionales se analizó el aumento o la disminución de las precipitaciones durante este periodo. Las anomalías de precipitación permitieron evaluar la estabilidad, el déficit o superávit de precipitación para cada año, y el método quintil permitió la clasificación de la intensidad de las sequías meteorológicas. Los resultados muestran una considerable variabilidad espacial y temporal, con mayores valores de precipitación y anomalías en la costa, que van disminuyendo gradualmente hacia el Centro-Oeste del área en estudio. Durante este periodo hay una disminución de la precipitación anual y de la estación húmeda, en gran parte de la zona la cual alcanza una disminución de 12 mm anuales (estación Chachobben). Estaciones como Zoh Laguna Campeche muestran claramente un aumento en los años de sequía (desde leve hasta extrema) a partir de 1985 principalmente. Este estudio contribuye a un major conocimiento de la variación regional de la precipitación y sus posibles vínculos con el Cambio Climático a escala regional y global.

Resumen en inglés

This study analyzes the spatial and temporal variability of precipitation across the Southern Yucatán Peninsula in Mexico, addressing the anomalies and trends of annual and seasonal precipitation as well as the occurrence of meteorological droughts, using rainfall data from nine weather stations during the period 1953-2007. Linear regression in the annual and seasonal rainfall were used to analyze the increase or decrease in precipitation trends over this period. Precipitation anomalies enabled the evaluation of the stability, deficit, or surplus of precipitation for each year or season, and a quintile method was used to classify the intensity of meteorological droughts. The results exhibit considerable spatial and temporal variability, with higher values of precipitation and precipitation anomalies at the Caribbean coast, which gradually decrease towards the mid-west of the region. Results exhibit a significant decrease in annual and rainy-season precipitation in much of the area cover in this study, by as much as 12 mm less per year (Chachobben station). Other weather stations, such as Zoh Laguna, show an increase in years of drought (ranging from mild to extreme), especially since the early 1980´s. We hope that the results of this study will contribute to a better understanding of regional precipitation variability, with links to broader-scale Climate Change.


7.
Artículo
Hurricane disturbance mapping using MODIS EVI data in the southeastern Yucatán, Mexico
Schneider, Laura C. ; Rogan, John ; Christman, Zachary John (coaut.) ; Millones, Marco (coaut.) ; Lawrence, Deborah (coaut.) ; Schmook, Birgit Inge (coaut.) ;
Contenido en: Remote Sensing Letters Vol. 2, no. 3 (September 2011), p. 259-267 ISSN: 2150-704X
Resumen en: Inglés |
Resumen en inglés

This letter evaluated the use of Moderate Resolution Imaging Spectroradiometer (MODIS) 250 mEnhanced Vegetation Index (EVI) standard product data (MOD/ MYD13Q1 C5) to map the damage caused by Hurricane Dean (August 2007) to the forests in the Yucata´n Peninsula of Mexico using a two-step vetting procedure. Sequences of MODIS EVI 16-day composite products captured before and after the hurricane were compared against 93 field damage plots to select an appropriate set of pre- and post-damage data. Aqua pairwise combinations produced the highest damage detection overall accuracy compared with Terra (82.4% vs. 73.8%, respectively) because of advantageous timing of the Aqua EVI compositing, relative to the hurricane event. The most accurate EVI damage map (91.4% overall) revealed highest damage detection in Saffir–Simpson hurricane wind scale zone 5 (i.e. wind speed .248 km h-1, i.e. 95%), followed by 93% in zone 4 (210–249 km h-1) and 87% in zone 3 (178–209 km h-1). Results indicate that MODIS EVI products provide timely and accurate maps of hurricane damage in subtropical forests.


8.
Artículo
Resumen en: Inglés |
Resumen en inglés

Shifting cultivators depend on forest biomass inputs to nourish their crops. For them, forest resilience has an immediate impact: it affects crop productivity. A decline in the rate of recovery following shifting cultivation would ultimately affect local, regional and global carbon budgets, with feedbacks to climate. Yet the long-term impacts of shifting cultivation have been quantified in only six locations. In this study, we reanalyze data from these locations to determine whether the rate of biomass recovery is the same from cycle to cycle. Further, using case studies in Southern Yucatan, Mexico and West Kalimantan, Indonesia, we investigate the ecological and socioeconomic factors that affect forest resilience and thus determine whether or not shifting cultivation is sustainable. The reanalysis links aboveground biomass recovery following shifting cultivation to site productivity, forest age, fallow length, history of cultivation, and soil texture. Across locations, biomass accumulation rate declines by 9.3 percent with each cycle of shifting cultivation. Per cycle change in biomass accumulation rate is significantly more negative in younger forests and forests that experience a shorter fallow period. However, more detailed analyses for two case studies suggest that a purely ecological framework is of limited effectiveness in explaining variability in the effect of repeated shifting cultivation. Rather, socioeconomic factors such as migration, subsidies, roads, and settlement history can alter the outcome of shifting cultivation by limiting the accumulation and use of local knowledge.


9.
Artículo
Land abandonment in an agricultural frontier after a plant invasion: the case of bracken fern in southern Yucatan, Mexico
Schneider, Laura C. ; Geoghean, Jacqueline (coaut.) ;
Clasificación: AR Y/631.477275 / S35
Contenido en: Agricultural and resource economics review Vol. 35, no. 1 (April 2006), p. 1-11 ISSN: 1068-2805
Bibliotecas: Chetumal
Cerrar
SIBE Chetumal
ECO030004604 (Disponible)
Disponibles para prestamo: 1
Resumen en: Inglés |
Resumen en inglés

Plant invasions and their impact on land use pose difficult research questions, due to the complex relationships between the ecological nature of the invasion and the human responses to the invasion. This paper focuses on the linkages between an invasion of bracken fern and land use decisions in an agricultural frontier in southern Mexico. Agriculture in this region is practiced on an extensive basis, using traditional slash-and-burn techniques of temporary cultivation and continuous rotation through forest fallow. We investigate the factors that affect the decision of a subsistence farmer to either continue cultivating an invaded agricultural plot or permanently abandon the plot and cultivate elsewhere. We develop an agricultural household model of land use choices, where households maximize utility subject to constraints on land, labor, and income. We subsequently test the hypotheses raised, using data from a small household survey performed in the region in 2002.


10.
Artículo
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Bracken fern invasion in southern Yucatán: a case for land change science
Schneider, Laura C. ;
Clasificación: AR Y/631.477265 / S3
Contenido en: Geographical Review Vol. 94, no. 2 (April 2004), p. 229-241 ISSN: 0016-O7428
Bibliotecas: Chetumal
Cerrar
SIBE Chetumal
ECO030004603 (Disponible)
Disponibles para prestamo: 1
Nota: Solicítelo con su bibliotecario/a