Papers by Antonio Gómez-sal
The paper describes an analytical procedure to preliminarily investigate large scale animal-envir... more The paper describes an analytical procedure to preliminarily investigate large scale animal-environment interactions. The method is based on Correspondence Analysis applied over a contingency table in which the columns are percentage categories of animal activities and the rows, states of environmental variables. Each cell entry in the table represents the number of times a row and a column have been recorded together. This means that investigation of animal-environment interactions does not require defining specific sampling stations, or subdividing the study area into environmental units; i.e. the method can be used in studies in which sampling consisted of following the animals and noting their activities and characteristics of the environment. The graphical display resulting from the analysis shows the main patterns of association between animal activities and environment, and its numerical output allows one to identify the variables that have played a major role in the display. Taking into account these variables and their associated animal activities, the method allows one to define archetypal habitat models for each animal activity. Correspondence Analysis of animal activities by environmental variable matrices may give insights about animal's perception of the environment. The use of the method is illustrated by analyzing habitat preferences of free-ranging cattle during 2 different seasons on an estate in Spain. Results indicate the validity of the method as a first global analysis of the relative importance of environmental variables for the distribution of the animal activities in the landscape.
In this paper 221 forest trees are grouped according to their habitat preferences into species pr... more In this paper 221 forest trees are grouped according to their habitat preferences into species preferring humid or dry and/or saline habitats or indifferent to the habitat type. Eleven functional traits classes (seeds per tree, seed size, seed weight, seeds per fruit, tolerance to shade, selectivity to habitat, sclerophylly, wood density, foliar area, tree height and tree volume) are arranged 1 to 4 according to a successional gradient. The strategies of forest trees are identified by analyzing the species matrices for humid forest ecosystems (joining species preferring humid habitats together with those indifferent to the habitat type) and for dry and/or saline ecosystems (joining species preferring dry and/or saline habitats and the ones indifferent to the habitat type). Both matrices are processed using the average taxonomic distance as the interval coefficient and by clustering analysis to discover successional organization patterns. The complexity of r-K continuum is discussed ...
WIT Press eBooks, Oct 14, 2013
The provision of environmental services from ecosystems is a growing area of research encouraged ... more The provision of environmental services from ecosystems is a growing area of research encouraged by the Millennium Ecosystem Assessment of the United Nations. Nevertheless, the experiences of services evaluation from the perspective of ecology are still scarce. In many traditional Central American towns, patios provide a considerable provision of services for human wellbeing, both for the important surface that they occupy and for the naturalness that they maintain. In the present work we studied the provision of environmental services from patios in León (Nicaragua). Forty patios of different characteristics (from colonial to indigenous roots) were selected by a stratified sampling design. The study shows the importance of goods supply (mostly fruits), microclimatic regulation, recreational values and support for wildlife (birds, iguanas and native useful plants). A progressive fragmentation of dwelling space is affecting all services provision, especially fruits and wildlife, with lesser incidence in microclimatic regulation and recreational values. The incorporation of tourism based on patios as a developing tool is discussed in the context of services evaluation. This new function, which has been incorporated in the management of some pPlot patios, can stimulate owners to preserve the original valuable characteristics of patios, and at the same time, consolidate the provision of other more strategic and basic services for the whole community.
Mountain Research and Development, Nov 5, 2021
BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.
Revista de Teledetección, 2019
Dehesas are high value agroecosystems that benefit from the effect tree cover has on pastures. Su... more Dehesas are high value agroecosystems that benefit from the effect tree cover has on pastures. Such effect occurs when tree cover is incomplete and homogeneous. Tree cover may be characterized from field data or through visual interpretation of remote sensing data, both time-consuming tasks. An alternative is the extraction of tree cover from aerial imagery using automated methods, on spectral derivate products (i.e. NDVI) or LiDAR point clouds. This study focuses on assessing and comparing methods for tree cover estimation from high resolution orthophotos and airborne laser scanning (ALS). RGB image processing based on thresholding of the ‘Excess Green minus Excess Red’ index with the Otsu method produced acceptable results (80%), lower than that obtained by thresholding the digital canopy model obtained from the ALS data (87%) or when combining RGB and LiDAR data (87.5%). The RGB information was found to be useful for tree delineation, although very vulnerable to confusion with th...
Acta Botánica Cubana, 2016
Sustainable Tourism III, 2008
The provision of environmental services from ecosystems is a growing area of research encouraged ... more The provision of environmental services from ecosystems is a growing area of research encouraged by the Millennium Ecosystem Assessment of the United Nations. Nevertheless, the experiences of services evaluation from the perspective of ecology are still scarce. In many traditional Central American towns, patios provide a considerable provision of services for human wellbeing, both for the important surface that they occupy and for the naturalness that they maintain. In the present work we studied the provision of environmental services from patios in León (Nicaragua). Forty patios of different characteristics (from colonial to indigenous roots) were selected by a stratified sampling design. The study shows the importance of goods supply (mostly fruits), microclimatic regulation, recreational values and support for wildlife (birds, iguanas and native useful plants). A progressive fragmentation of dwelling space is affecting all services provision, especially fruits and wildlife, with lesser incidence in microclimatic regulation and recreational values. The incorporation of tourism based on patios as a developing tool is discussed in the context of services evaluation. This new function, which has been incorporated in the management of some pPlot patios, can stimulate owners to preserve the original valuable characteristics of patios, and at the same time, consolidate the provision of other more strategic and basic services for the whole community.
Journal of Arid Environments, 2011
Trabajo presentado en el 18th International Symposium on Analytical and Applied Pyrolysis, celebr... more Trabajo presentado en el 18th International Symposium on Analytical and Applied Pyrolysis, celebrado en Lanzarote del 18 al 23 de mayo de 2008.
Plant Ecology, 2002
A factorial field experiment was used to assess the influence of soil-disturber mammals in the st... more A factorial field experiment was used to assess the influence of soil-disturber mammals in the structure of a 9-year-old Mediterranean annual plant community subjected to different sheep grazing and irrigation regimes. We estimated the disturbance rate (mound building activity) by Mediterranean voles, their effects on vegetation and the mechanisms of these effects during a period of vole outbreak. The effects
Journal of Range Management, 1997
The paper describes an analytical procedure to preliminarily investigate large scale animal-envir... more The paper describes an analytical procedure to preliminarily investigate large scale animal-environment interactions. The method is based on Correspondence Analysis applied over a contingency table in which the columns are percentage categories of animal activities and the rows, states of environmental variables. Each cell entry in the table represents the number of times a row and a column have been recorded together. This means that investigation of animal-environment interactions does not require defining specific sampling stations, or subdividing the study area into environmental units; i.e. the method can be used in studies in which sampling consisted of following the animals and noting their activities and characteristics of the environment. The graphical display resulting from the analysis shows the main patterns of association between animal activities and environment, and its numerical output allows one to identify the variables that have played a major role in the display. Taking into account these variables and their associated animal activities, the method allows one to define archetypal habitat models for each animal activity. Correspondence Analysis of animal activities by environmental variable matrices may give insights about animal's perception of the environment. The use of the method is illustrated by analyzing habitat preferences of free-ranging cattle during 2 different seasons on an estate in Spain. Results indicate the validity of the method as a first global analysis of the relative importance of environmental variables for the distribution of the animal activities in the landscape.
Landscape Ecology, 2022
Context Domesticated animals play a central role in agricultural landscapes. However, livestock h... more Context Domesticated animals play a central role in agricultural landscapes. However, livestock has been scarcely studied from a spatial perspective. Mapping of livestock diversity has been limited by the lack of distribution and demography data. This shortfall limits both the reach of actions aimed to conserve threatened breeds and their consideration as a tool for improving sustainability in livestock landscapes. Objectives To analyse environmental drivers of local grazing livestock breed—those autochthonous to a specific region—distributions and delineate livestock ecoregions, i.e. areas where certain groups of breeds exhibit similarly response to environmental factors in their distribution. Methods We used non-metric multidimensional scaling and hierarchical clustering to explore the distribution of the areas of origin of 119 local livestock breeds of the bovine, ovine, caprine, equine and asinine species. In addition, we performed randomisations and preference index to establis...
Animals
There is an increasing interest in assessing livestock breed contributions to ecosystem services ... more There is an increasing interest in assessing livestock breed contributions to ecosystem services (ES) and including this knowledge in decision making. However, this task has been limited due to the complexity of the multidimensional relationship between livestock diversity and ecosystem services. In this work, we elaborate on the livestock breed characteristics central to developing a comprehensive approach to livestock breed inclusion in the ecosystem services framework. Thus, we explore the multidimensional nature of livestock breeds, i.e., as eco-cultural entities, biodiversity components, and drivers of livestock system heterogeneity and functioning. First, anthropogenic and natural factors have acted jointly to develop breeds as eco-cultural entities. This fact represents an opportunity to move toward farming system sustainability by Nature-Based Solutions and Nature’s Contribution to People paradigms. Second, livestock breeds are components of biodiversity, and as such, can be...
Land, 2021
In the coastal zones, varied uses converge, some of them of priority interest. In this study, an ... more In the coastal zones, varied uses converge, some of them of priority interest. In this study, an integrated method for the planning and management of the territory is proposed, which includes the evaluation of sustainability. A total of 15 different land-use classes were estimated in 80 sampling units distributed regularly along the Pacific coastline of Nicaragua and classified to determine land management sectors. For each of the identified sectors, the ecological, economic, social, and productive dimensions were evaluated independently, handling a total of 53 variables from different databases, by means of ordination multivariate factor analysis. Subsequently, the four dimensions were integrated into a model and the results were evaluated based on their similarity with theoretical development scenarios, assessed by discriminant analysis. Among these, the scenarios considered as a goal for sustainability in the studied area were present. On the Pacific coast of Nicaragua, productiv...
Pirineos, 1993
The spatial distribution and competition for the use of resources between sheep —transhumant meri... more The spatial distribution and competition for the use of resources between sheep —transhumant merino— and chamois Rupicapra pyrenaica parva . Cabrera, 1910) has been analyzed during the summer grazing period in the Cantabrian range. The studied area, —a 750 ha. wide high pass— was divided into sectors depending on geophysical variables (substratum, aspect and elevation) and vegetation types. Sheep land use was analyzed by direct observation of the flock and by means of enquiries to the shepherd. Chamois were studied before and during the time sheep were present in the pastureland, with the help of fixed itineraries that enabled us to visually cover the whole area. The assessment of land use was carried out by corrected frequency and preference index for each of the studied environmental variables. Sheep grazed in the whole area excepting for beech woods ( Fagus sylvatica ), rocky and steep zones and dense scrub patches. The location of the sheepfolds —shelters, enclosures and associa...
Vegetatio, 1992
The transfer of matter by cattle in a 'dehesa' patureland in Central Spain has been quantified by... more The transfer of matter by cattle in a 'dehesa' patureland in Central Spain has been quantified by mapping the distribution of dung and different types of cattle behaviour in several areas distinguished by their geomorphological position, vegetation structure and management regime. Cattle show a clear preference for feeding and dung depositing in the low parts of the estate. This leads to an increase in the productivity and a rapid recycling of nutrients in the pasture communities of these areas. Comparing the relative importance of both processes in each vegetational unit, dung accumulation is greater in the higher zones, while in the lower areas biomass consumption is more important. This means that movement of matter by cattle tends to favour the higher ground, in a contrary direction to the downward leaching of nutrients and related processes. In the studied dehesa, this phenomena represents an 'exploitation' factor of the lowland areas, which maintains productive pasture communities more immature in successional terms, by the higher woodland areas, less grazed and with low turnover. This result supports claims made in other studies that animal activity-assessed in our case by the relative impacts of herbivory and dung depositions-connect adjacent ecosystems and thus tends to improve the net energy balance of the more successionally mature part of the system. Livestock movements differ in their spatial pattern during different periods of the year: dispersing in spring and becoming more concentrated and predictable during winter. The clear seasonal differences of herbaceous production in Mediterranean climates and the management activities (basically ploughing, tree pruning and fodder supply) are the main causes of this pattern.
Oikos, 1994
Frank and McNaughton reported that community stability, measured by the resistance to change in s... more Frank and McNaughton reported that community stability, measured by the resistance to change in species composition when perturbed by drought, increased with species diversity in grasslands of Yellowstone, USA. They also found that species diversity increased with ...
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Papers by Antonio Gómez-sal