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1.
Carbon Balance Manag ; 15(1): 15, 2020 Jul 29.
Article En | MEDLINE | ID: mdl-32729000

BACKGROUND: Reliable information about the spatial distribution of aboveground biomass (AGB) in tropical forests is fundamental for climate change mitigation and for maintaining carbon stocks. Recent AGB maps at continental and national scales have shown large uncertainties, particularly in tropical areas with high AGB values. Errors in AGB maps are linked to the quality of plot data used to calibrate remote sensing products, and the ability of radar data to map high AGB forest. Here we suggest an approach to improve the accuracy of AGB maps and test this approach with a case study of the tropical forests of the Yucatan peninsula, where the accuracy of AGB mapping is lower than other forest types in Mexico. To reduce the errors in field data, National Forest Inventory (NFI) plots were corrected to consider small trees. Temporal differences between NFI plots and imagery acquisition were addressed by considering biomass changes over time. To overcome issues related to saturation of radar backscatter, we incorporate radar texture metrics and climate data to improve the accuracy of AGB maps. Finally, we increased the number of sampling plots using biomass estimates derived from LiDAR data to assess if increasing sample size could improve the accuracy of AGB estimates. RESULTS: Correcting NFI plot data for both small trees and temporal differences between field and remotely sensed measurements reduced the relative error of biomass estimates by 12.2%. Using a machine learning algorithm, Random Forest, with corrected field plot data, backscatter and surface texture from the L-band synthetic aperture radar (PALSAR) installed on the on the Advanced Land Observing Satellite-1 (ALOS), and climatic water deficit data improved the accuracy of the maps obtained in this study as compared to previous studies (R2 = 0.44 vs R2 = 0.32). However, using sample plots derived from LiDAR data to increase sample size did not improve accuracy of AGB maps (R2 = 0.26). CONCLUSIONS: This study reveals that the suggested approach has the potential to improve AGB maps of tropical dry forests and shows predictors of AGB that should be considered in future studies. Our results highlight the importance of using ecological knowledge to correct errors associated with both the plot-level biomass estimates and the mismatch between field and remotely sensed data.

3.
PLoS One ; 14(9): e0222908, 2019.
Article En | MEDLINE | ID: mdl-31553749

Quantifying patterns of deforestation and linking these patterns to potentially influencing variables is a key component of modelling and projecting land use change. Statistical methods based on null hypothesis testing are only partially successful for interpreting deforestation in the context of the processes that have led to their formation. Simplifications of cause-consequence relationships that are difficult to support empirically may influence environment and development policies because they suggest simple solutions to complex problems. Deforestation is a complex process driven by multiple proximate and underlying factors and a range of scales. In this study we use a multivariate statistical analysis to provide contextual explanation for deforestation in the Usumacinta River Basin based on partial pattern matching. Our approach avoided testing trivial null hypotheses of lack of association and investigated the strength and form of the response to drivers. As not all factors involved in deforestation are easily mapped as GIS layers, analytical challenges arise due to lack of a one to one correspondence between mappable attributes and drivers. We avoided testing simple statistical hypotheses such as the detectability of a significant linear relationship between deforestation and proximity to roads or water. We developed a series of informative generalised additive models based on combinations of layers that corresponded to hypotheses regarding processes. The importance of the variables representing accessibility was emphasised by the analysis. We provide evidence that land tenure is a critical factor in shaping the decision to deforest and that direct beam insolation has an effect associated with fire frequency and intensity. The effect of winter insolation was found to have many applied implications for land management. The methodology was useful for interpreting the relative importance of sets of variables representing drivers of deforestation. It was an informative approach, thus allowing the construction of a comprehensive understanding of its causes.


Conservation of Natural Resources/trends , Forests , Models, Statistical , Spatial Analysis , Conservation of Natural Resources/statistics & numerical data , Forecasting/methods , Mexico , Rivers
4.
J Environ Manage ; 230: 392-404, 2019 Jan 15.
Article En | MEDLINE | ID: mdl-30296677

There is increasing recognition that ecosystems and their services need to be managed at landscape scale and greater. The development of landscape-scale conservation strategies need to incorporate information from multiple sources. In this study, we combine various research tools to link landscape patterns with production units and systems in the Usumacinta River Basin, and inform the discussion of key questions around decision-making related to conservation action and policy in Southern Mexico. A typology based on policy-relevant farmer characteristics (land tenure, farm size, source of income, farming system) differentiated between farmers (traditional vs. cattle ranching) with different motivations that determine how management affects landscape configuration. Five main types of traditional farming systems were identified that combine different forms of land use and vary in their degree of land intensification. Major fragmentation and decrease in connectivity coincided spatially with floodplains dominated by large-scale commercial farms that specialize in livestock production. Traditional practices within large units with low-sloped high quality land were also seen to be intensive; however the presence of trees was notable throughout these units. Policies that promote livestock farming are among the principle causes motivating deforestation. Land intensification by traditional farmers decreased as the landscape became increasingly rugged. Traditional farmers are the focus of initiatives developed by the Biological Corridor project which seeks to increase forest cover and landscape connectivity. These initiatives have shown high levels of rural participation (10,010 farmers benefited from 27,778 projects involving 95,374 ha of land) and acceptance (producers carried out more than one project and several types of projects during the first eight years of work). Strong action is still required to take on the segment of large-scale ranchers. Changes in the structure of land tenure over the past decade are highlighted that could have a profound impact on conservation policies and programs.


Agriculture , Rivers , Agriculture/methods , Animals , Cattle , Conservation of Natural Resources , Ecosystem , Farmers , Farms , Income , Mexico , Trees
5.
Rev. esp. geriatr. gerontol. (Ed. impr.) ; 49(1): 10-14, ene.-feb. 2014.
Article Es | IBECS | ID: ibc-118621

Introducción. El dolor está considerado como un grave problema en el entorno residencial afectando entre un 49 y un 83% de los residentes. El proceso evolutivo de la enfermedad de Alzheimer puede conllevar dificultades de comunicación y comprensión de las escalas de evaluación de dolor, dificultando su evaluación y tratamiento. El objetivo principal de este estudio fue validar la versión española del PAINAD (PAINAD-Sp) y evaluar su aplicabilidad en un Centro Gerontológico en España. Material y métodos. Veinte usuarias diagnosticadas de demencia avanzada fueron observadas por 5 observadores con diferentes perfiles profesionales durante 5 min en 3 condiciones: reposo, durante actividad agradable y en situación de dolor. La PAINAD-Sp fue administrada simultáneamente a una escala analógica visual. Resultados. Los resultados muestran que el alfa de Cronbach se encontraba entre 0,467 y 0,827 (con una media de 0,692, que subía si el ítem de respiración se eliminaba). La fiabilidad interjueces variaba entre 0,587 y 0,956. La correlación entre la medida total en PAINAD-Sp y en una Escala Visual Analógica fue estadísticamente significativa (p < 0,05) en todas las medidas y variaba entre 0,517 y 0,868. Conclusiones. Los resultados del estudio muestran que la escala PAINAD-Sp es eficaz para medir el dolor en personas con demencia sin capacidad de comunicación. Esta escala puede ser usada por diferentes profesionales de la salud con poco entrenamiento y presenta una buena fiabilidad (AU)


Introduction. Pain in elderly people is considered a major concern in nursing home facilities affecting between 49% and 83% of the residents. Progression of Alzheimer's Disease causes more communication difficulties in patients with advanced dementia and therefore more problems to understand even the most simple pain evaluation scales. Identification and implementation of appropriate pain management strategies depends on an adequate pain assessment. Material and methods. The main objective of the study was to validate the Spanish version of the PAINAD Scale (PAINAD-Sp) and to assess its applicability in Spanish Geriatric Nursing Homes. The 20 patients diagnosed with severe dementia from a Geriatric Centre in Spain were observed by five observers with different professional profiles for 5 minutes to each participant, and PAINAD-Sp Scale was administered simultaneously to a Visual Analogical Scale-VAS. Three different observational conditions were established: resting condition, during presumably pleasant activity and during presumable painful activity. Results. Cronbach's alpha ranged between 0.467 and 0.827 (average 0.692), and rose if Breathing item was deleted. Inter-rater reliability ranged between 0.587 and 0.956. Correlation between PAINAD-Sp Scale total measures and VAS was statistically significant (P<.05) in all measures and ranged from 0.517 to 0.868. Conclusions. Findings in the study showed that the scale is useful to measure pain in non communicative patients suffering from dementia. The scale maintains good levels of reliability for different healthcare professionals even when they have little training (AU)


Humans , Female , Aged , Aged, 80 and over , Pain , Dementia/diagnosis , Dementia/psychology , Mental Status Schedule , Alzheimer Disease/epidemiology , Alzheimer Disease/prevention & control , Reproducibility of Results/methods , Reproducibility of Results/trends , Reproducibility of Results , Data Analysis/methods , Pain Management/methods , Pain Management
6.
Rev Esp Geriatr Gerontol ; 49(1): 10-4, 2014.
Article Es | MEDLINE | ID: mdl-23746393

INTRODUCTION: Pain in elderly people is considered a major concern in nursing home facilities affecting between 49% and 83% of the residents. Progression of Alzheimer's Disease causes more communication difficulties in patients with advanced dementia and therefore more problems to understand even the most simple pain evaluation scales. Identification and implementation of appropriate pain management strategies depends on an adequate pain assessment. MATERIAL AND METHODS: The main objective of the study was to validate the Spanish version of the PAINAD Scale (PAINAD-Sp) and to assess its applicability in Spanish Geriatric Nursing Homes. The 20 patients diagnosed with severe dementia from a Geriatric Centre in Spain were observed by five observers with different professional profiles for 5 minutes to each participant, and PAINAD-Sp Scale was administered simultaneously to a Visual Analogical Scale-VAS. Three different observational conditions were established: resting condition, during presumably pleasant activity and during presumable painful activity. RESULTS: Cronbach's alpha ranged between 0.467 and 0.827 (average 0.692), and rose if Breathing item was deleted. Inter-rater reliability ranged between 0.587 and 0.956. Correlation between PAINAD-Sp Scale total measures and VAS was statistically significant (P<.05) in all measures and ranged from 0.517 to 0.868. CONCLUSIONS: Findings in the study showed that the scale is useful to measure pain in non communicative patients suffering from dementia. The scale maintains good levels of reliability for different healthcare professionals even when they have little training.


Dementia , Pain Measurement , Aged , Aged, 80 and over , Female , Humans , Language , Reproducibility of Results , Severity of Illness Index
7.
PLoS One ; 7(8): e42309, 2012.
Article En | MEDLINE | ID: mdl-22905123

Case studies of land use change have suggested that deforestation across Southern Mexico is accelerating. However, forest transition theory predicts that trajectories of change can be modified by economic factors, leading to spatial and temporal heterogeneity in rates of change that may take the form of the Environmental Kuznets Curve (EKC). This study aimed to assess the evidence regarding potential forest transition in Southern Mexico by classifying regional forest cover change using Landsat imagery from 1990 through to 2006. Patterns of forest cover change were found to be complex and non-linear. When rates of forest loss were averaged over 342 municipalities using mixed-effects modelling the results showed a significant (p<0.001) overall reduction of the mean rate of forest loss from 0.85% per year in the 1990-2000 period to 0.67% in the 2000-2006 period. The overall regional annual rate of deforestation has fallen from 0.33% to 0.28% from the 1990s to 2000s. A high proportion of the spatial variability in forest cover change cannot be explained statistically. However analysis using spline based general additive models detected underlying relationships between forest cover and income or population density of a form consistent with the EKC. The incipient forest transition has not, as yet, resulted in widespread reforestation. Forest recovery remains below 0.20% per year. Reforestation is mostly the result of passive processes associated with reductions in the intensity of land use. Deforestation continues to occur at high rates in some focal areas. A transition could be accelerated if there were a broader recognition among policy makers that the regional rate of forest loss has now begun to fall. The changing trajectory provides an opportunity to actively restore forest cover through stimulating afforestation and stimulating more sustainable land use practices. The results have clear implications for policy aimed at carbon sequestration through reducing deforestation and enhancing forest growth.


Agriculture/methods , Conservation of Natural Resources/methods , Forestry/methods , Trees/growth & development , Animals , Conservation of Natural Resources/trends , Ecology , Ecosystem , Environmental Monitoring/methods , Geography , Mexico , Models, Statistical , Models, Theoretical
8.
Environ Manage ; 49(3): 649-62, 2012 Mar.
Article En | MEDLINE | ID: mdl-22218460

Livelihoods of people living in many protected areas (PAs) around the world are in conflict with biodiversity conservation. In Mexico, the decrees of creation of biosphere reserves state that rural communities with the right to use buffer zones must avoid deforestation and their land uses must become sustainable, a task which is not easily accomplished. The objectives of this paper are: (a) to analyze the conflict between people's livelihoods and ecosystem protection in the PAs of the Sierra Madre de Chiapas (SMC), paying special attention to the rates and causes of deforestation and (b) to review policy options to ensure forest and ecosystem conservation in these PAs, including the existing payments for environmental services system and improvements thereof as well as options for sustainable land management. We found that the three largest PAs in the SMC are still largely forested, and deforestation rates have decreased since 2000. Cases of forest conversion are located in specific zones and are related to agrarian and political conflicts as well as growing economic inequality and population numbers. These problems could cause an increase in forest loss in the near future. Payments for environmental services and access to carbon markets are identified as options to ensure forest permanence but still face problems. Challenges for the future are to integrate these incentive mechanisms with sustainable land management and a stronger involvement of land holders in conservation.


Agriculture , Conservation of Natural Resources/economics , Conservation of Natural Resources/methods , Forestry , Animal Husbandry , Biodiversity , Conservation of Natural Resources/legislation & jurisprudence , Environmental Policy , Mexico
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