Papers by Mario González-espinosa
Revista De Biologia Tropical, May 27, 2015
In the highlands of Chiapas, rapid habitat destruction and alteration threaten epiphytes. Presuma... more In the highlands of Chiapas, rapid habitat destruction and alteration threaten epiphytes. Presumably, forest transformation increases open and border-type vegetation, characterized by drier conditions tban those prevailing deeper in tbe foresto If so, mesic epiphytes should be especially affected. We investigated tbe role of water availability during tbe growtb of a population of tbe wide-ranging mesic C3 phytotelm bromeliad Tillandsia guatemalensis. Chiapas experiences a pronounced dry season from November to April when average monthly precipitation falls below 30 mm. T. guatemalensis observed in situ released seeds duri ng this interval and high gerrnination rates occurred about seven weeks after tbe rainy weatber returned (over 93%, an observa tion confirmed in tbe laboratory). Many of tbe tiny seedlings disappeared before they could anchor to tbe sub strate, probably flushed off by torrential rains. Over half oflhe seedlings comprising a naturally established pop ulation died during tbe dry season. High seedling mortality was also dedueed from tbe size-class structure of nat ural populations. Seedling mortality on bark taken from tbe tree base up to a height of 1.3 m of bigger trees is similar on two species of oak compared to two species of pine. These barks also possessed high water retaining capacity. Oak bark derived from higher up tbe tree, however, absorbed a larger amount of water per surface area and liberated water during a longer period of time tban the bark of Pinus tecunumanii taken from similar loca tions on tbe host tree. Additionally, the water retaining capacity of tbe bark of larger trees was generally greater. We suggest tbat such differences in water retaining capacity explain, at least in part, why epiphytes favor oaks, the lower parts of pine trees, and larger (older) trees. After tbe development of tbe phytotelm growtb form, mor tality in a natural population falls. Our experirnents on phytotelm plants tbat appeared stressed after being trans planted out of tbeir original habitat suggest that nutrients are lirniting growth.
Revista Mexicana De Biodiversidad, Dec 1, 2017
Investigación ecológica participativa como apoyo de procesos de manejo y restauración forestal, a... more Investigación ecológica participativa como apoyo de procesos de manejo y restauración forestal, agroforestal y silvopastoril en territorios campesinos. Experiencias recientes y retos en la sierra Madre de Chiapas, México Participatory ecological research supporting forest, agroforest and silvopastoral restoration in peasant territories. Recent experiences and challenges in the Sierra Madre de Chiapas, Mexico
CABI eBooks, 2007
A sound analysis of the long-term implications of fragmentation and habitat loss for forest biodi... more A sound analysis of the long-term implications of fragmentation and habitat loss for forest biodiversity requires the identification of the mechanisms underlying forest structure and composition. In this chapter we compile evidence from several multi-scale empirical and theoretical studies conducted in the Central Highlands of Chiapas to propose possible mechanisms underlying observed tree species richness patterns. In agreement with a niche-based perspective, tree segregation and coexistence patterns at regional scales provide partial evidence of niche differentiation along environmental gradients. Also recruitment patterns and Markovian models of stand composition parameterized at local scales suggest differential regeneration niches and a predictable successional dynamics with convergence towards a forest dominated by a broadleaved canopy. However, both the scales of unaccounted spatial variation in regional models of stand composition and the existence of predictable local successional dynamics associated with guild groups rather than species (pines, oaks, canopy broadleaves and understorey broadleaves) support the idea of neutral processes operating within guilds or functional groups. These results suggest that from a theoretical point of view pine-oak forests of the Highlands of Chiapas are an intermediate stage between highly diverse humid tropical forests and more simplified pine-oak temperate forests, with segregation and coexistence among a given number of functional groups or guilds, but also with neutral mechanisms driving community composition at more local scales. From a management perspective, in addition to the preservation of large fragments (as implied from neutral theories), the forest area preserved or to be restored should include a representative array of forest habitat types (as implied from a niche-based perspective) arranged so that spatial proximity among fragments and connectivity is maximized.
Acta Botanica Mexicana, Jan 7, 2020
Antecedentes y Objetivos: En los bosques tropicales la inundación estacional puede actuar como fi... more Antecedentes y Objetivos: En los bosques tropicales la inundación estacional puede actuar como filtro ambiental afectando la supervivencia, el establecimiento y el crecimiento de las plántulas de especies arbóreas e influir en la estructura de las comunidades. Se simularon condiciones de inundación y sequía con el objetivo de evaluar su efecto como filtro ambiental sobre la supervivencia, crecimiento (longitud del tallo y número de hojas) y biomasa acumulada en plántulas de Brosimum alicastrum y Psidium sartorianum de la selva de Campeche, México. Métodos: Se estableció un experimento en condiciones de vivero con un diseño completamente al azar, con tres tratamientos (sequía, riego regular e inundación). Para cada tratamiento se utilizaron 45 plántulas de cada especie. Se evaluaron la supervivencia, altura y número de hojas de las plántulas al inicio del experimento y a intervalos de 30 días hasta su conclusión a los 120 días. Al finalizar, se cosecharon las plántulas y se midió la longitud de las raíces y la biomasa acumulada. Resultados clave: La inundación disminuyó la supervivencia de plántulas de B. alicastrum y no la de P. sartorianum, limitó la longitud del tallo, el número de hojas y la biomasa acumulada de ambas especies, pero no la biomasa de raíces de P. sartorianum. La supervivencia de las plántulas expuestas a sequía y riego regular no cambió y aumentó el crecimiento y biomasa acumulada. Conclusiones: Las respuestas de las especies contribuyeron a entender el papel del filtro ambiental en el establecimiento de las plántulas de especies arbóreas en los bajos de Calakmul, Campeche. La inundación estacional actúa como un filtro ambiental, elimina las plántulas de B. alicastrum en los bajos, mientras que esta especie predomina en áreas con suelos bien drenados como los lomeríos adyacentes a la zona inundada. Psidium sartorianum se adaptó a las condiciones de sequía e inundación, como se observa en su hábitat natural.
El Herbario CAS es reconocido internacionalmente como el poseedor de la colección más completa y ... more El Herbario CAS es reconocido internacionalmente como el poseedor de la colección más completa y actualizada de flora chiapaneca, de la cual disponen de ca. 90,000 ejemplares; esta riqueza se debe a la labor de colecta del Dr. Dennis E. Breedlove. El Herbario de la Academia de Ciencias de California tiene interés en computarizar a largo plazo toda su colección. Con el apoyo de esta propuesta se podrá completar lo que se ha iniciado en CAS respecto a las especies arbóreas de Los Altos de Chiapas, lo cual se estima en unos 4000-5000 registros adicionales y ampliar la base de datos para incluir todas las especies arbóreas de todas las regiones de Chiapas con base en el listado de Breedlove (1986) y otras fuentes que permitan actualizarlo. Reino: 1 Filo: 1 Clase: 1 Orden: 40 Familia: 113 Género: 451 Subgénero: 3 Especie: 1311 Epitetoinfraespecifico: 112
… : Revista científica y …, 2002
Los patrones de uso del suelo pueden alterar la composición y estructura de los bosques, y en con... more Los patrones de uso del suelo pueden alterar la composición y estructura de los bosques, y en consecuencia, las condiciones ecológicas para la regeneración de las especies nativas. En las últimas décadas en Los Altos de Chiapas, una región densamente poblada por ...
The Southwestern Naturalist, 1992
ABSTRACT Different microsites affected the removal of O. streptacantha seeds (1, 10, or 100 seeds... more ABSTRACT Different microsites affected the removal of O. streptacantha seeds (1, 10, or 100 seeds/clump) by rodents and the 5-month survivorship of transplanted seedlings. However, no microsite effects were found after 17 months on the survivorship of naturally established seedlings, indicating that this component of habitat heterogeneity may have a vanishing effect as the surviving plant grows. The results point to some of the difficulties associated with perennial species when evaluating the consequences of seed dispersal on adult fitness.
Frontiers in Ecology and the Environment, 2010
Iforest - Biogeosciences and Forestry, Aug 2, 2015
Attributes and frequency of forest gaps are usually described in reference to a one-dimensional g... more Attributes and frequency of forest gaps are usually described in reference to a one-dimensional gradient of light, which may relate to their disturbance dynamics. Similarly, species are customarily classified by their light response. We propose a bi-dimensional light framework that facilitates the understanding and comparison of forest systems and the understanding of plant responses to the complex light environment. This light plane is based on two spatially related components: (1) light received directly on a particular point (Focal); and (2) a statistical summary of the immediate environment representing the light conditions surrounding that point (Context). The contrast between these two values is null when Focal=Context and positive when Focal>Context or otherwise negative. Light was assessed using hemispherical photographs using a spatial arrangement of pictures spaced ~3 m in-between. Eight forest plots were surveyed, each with a central gap of different size. Sapling performance of Alnus acuminata, Cornus excelsa, Liquidambar styraciflua, Persea americana and Quercus laurina was also assessed within these plots. Measurements of stem height, basal diameter, and slenderness allometry were taken over a period of more than two years. We found in the light plane that plots were distributed in a pattern congruent with their estimated degree of disturbance (gap size), which spanned wide areas in the plane. Liquidambar styraciflua. and Quercus laurina were found to be sensitive to focal light, irrespective of context light. All species responded to focal light under negative contrast. Cornus and Persea grew taller and more slender as focal light increased, particularly under null contrast. There is evidence suggesting that plant growth is dependent on the contrast measured. Thus, it would be relevant to devise a functional classification of tree species that considers their response to both direct light and luminosity of the immediate environment as measured by a contrast value.
Polibotánica, Jul 1, 2019
Folia entomológica mexicana, 1990
Journal of Vegetation Science, Jun 1, 1991
We present floristic and structural data on serai plant communities (Old‐Field, Grassland, Shrubl... more We present floristic and structural data on serai plant communities (Old‐Field, Grassland, Shrubland, and Early Successional, Mid‐Successional, and Mature Forest) resulting from the current land use pattern in the Pinus‐Quercus forests in the highlands of Chiapas, Mexico. The number of species ranged from 24 in the Old‐Field stage up to 100 in the Mature Forest, and the shrub layer was richest in all the forested stands. An almost complete floristic replacement exists between the open and the forested communities. Quercus and Pinus dominate the canopy of old‐growth stands, but their recruitment does not occur or is very low in the shade. Vigorous seedlings and saplings of these species are found only in the open serai stages or in forest gaps. Demographic and phytosociological data are used to indicate the successional role of dominant species in the forested stages. Some implications of the regional land use patterns for conservation and succession are discussed.
Restoration Ecology, Dec 21, 2022
Ecological restoration is a viable strategy to recover floristic, structural, and functional attr... more Ecological restoration is a viable strategy to recover floristic, structural, and functional attributes of the very vulnerable and widely degraded tropical mountain forests. Most restoration efforts in these highly diverse and narrowly distributed systems involve unassisted forest regeneration or enrichment planting with a small number of species, usually those with commercial value and success evaluated after a few years. We assessed changes in soil attributes, forest composition and structure in four sites with plots under unassisted forest regeneration or enrichment planting. The sites are in the limestone massif of the central highlands of Chiapas (Mexico) and share geological, edaphic and climatic conditions, but differ in level of previous disturbance and the time elapsed since the enrichment planting (16–30 years). No changes in soil variables (contents of C, N, P, and K, cation exchange capacity, and pH) were detected. Total density of juveniles was not consistently related to unassisted forest regeneration or enrichment planting but was highest in the two sites that had severe disturbance level. Influence of enrichment planting on forest regeneration depended on the composition and structure of the surrounding stands, and more so when opportunistic trees like pines and other shade‐intolerant species are available. Yet long‐lived shade‐tolerant species, including oaks, which may have synergistic effects during forest recovery, were well represented in sites with original severe disturbance level.
Journal of Vegetation Science, Mar 28, 2023
QuestionUnderstanding the specific distribution patterns of vascular plants on different spatial ... more QuestionUnderstanding the specific distribution patterns of vascular plants on different spatial scales is central in ecology and conservation. We evaluate the distribution patterns of five plant life forms (climbers, epiphytes, herbs, shrubs, and trees) along the elevation gradient and geographic space of a mountain system, analyzing climate, topography, and human disturbance to explain variation in the richness of each life form, and determine the contribution of each life form to total richness along the elevation gradient.LocationSierra Madre of Chiapas, southeastern Mexico.MethodsWe used linear models to evaluate the elevational pattern of richness for each life form, as well as total richness, and analyzed the effects of climate (water–energy dynamics, thermal range), topography (topographic heterogeneity), and disturbance (Human Influence Index) on variation in total richness as well as of each life form using Generalized Linear Models (GLM). We used Non‐Metric Multidimensional (Distance) Scaling to determine variation in species composition along the elevation gradient. Finally, the contribution of each life form to total richness was evaluated using GLM.ResultsWe recorded 235 families, 1,439 genera, and 5,196 species. Total richness and the richness of each life form increased with increasing elevation. GLM explained a high proportion of the variation in the richness of each life form (34.3% for total richness; climbers 17.2%, epiphytes 44.9%, herbs 20.4%, shrubs 33.5%, and trees 24.9%). The proportion of richness of herbs and trees to total richness decreased, and the proportion of shrubs, epiphytes, and climbers increased with elevation. Climate largely determined species richness for all life forms, whereas disturbance was significant only for epiphyte richness.ConclusionsResults suggest that mechanisms driven by climatic variables (especially thermal range) contribute to maintaining the richness of each life form. However, human disturbance modifies distribution patterns and leads to a decrease in epiphyte richness. The differential contribution of each life form to total richness along the elevation gradient presents a challenge for designing conservation strategies applicable to all plant groups.
The objective was to characterize water quality for a section of the Grijalva River and its tribu... more The objective was to characterize water quality for a section of the Grijalva River and its tributaries, for rainy and dry season in the border of the States of Chiapas and Tabasco. 23 physical, chemical, and microbiological parameters as well as contaminants were determined and compared with the Mexican norm NOM-127-SSA1-1994 which establishes water quality maximum permissible limits for use and human consumption and with the water quality classification scale proposed by the Comisión Nacional del Agua. Water quality of the Grijalva River in the studied section and tributaries, also locally named Almandros river, decreases as it descends to more populated areas of Tabasco. Water turbidity and high levels of coliforms and Escherichia are the main problems associated with the rivers of the studied area, even in water sources destined for human consumption. Other studied parameters have acceptable water quality mainly during the dry season, except for Mercury, which showed higher levels than the recommended by the norm in all sampling sites. The need to further study presence of Mercury in the Grijalva River basin is suggested
Botanical Sciences
El uso extendido de Cupressus lusitanica para reforestar áreas degradadas puede reducir la riquez... more El uso extendido de Cupressus lusitanica para reforestar áreas degradadas puede reducir la riqueza y diversidad de bosques húmedos de montaña. Se comparó la composición y estructura de la vegetación leñosa de un área reforestada con C. lusitanica con la de fragmentos de bosque de Pinus-Quercus y bosques secundarios de pino-encino en Los Altos de Chiapas. Los tres tipos de bosque presentaron diferencias significativas ( P ? 0.01) en cobertura, riqueza y diversidad de especies leñosas. La mayor área basal de árboles grandes se registró en el bosque de Pinus-Quercus (38.7 m2ha-1) seguida del bosque secundario (16.5 m2ha-1) y la más baja en el sitio reforestado con Cupressus (12.7 m2ha-1). Aunque la menor riqueza ( P ? 0.05) de especies arbóreas se registró en esta última condición (16 especies), comparada con el bosque de Pinus-Quercus (18) y el bosque secundario (30 especies), la diversidad de árboles (> 10 cm de diámetro a la altura del pecho) resultó mayor en el sitio reforestado...
Mechanisms explaining patterns of biodiversity along elevation gradients in tropical mountain sys... more Mechanisms explaining patterns of biodiversity along elevation gradients in tropical mountain systems remain controversial. We use a set of climatic, topographic and soil variables encompassing regional, landscape and local-level spatial scales to explain the spatial variation of tree species diversity in the Sierra Madre of Chiapas, Mexico. We sampled 128 circular plots (0.1-ha each) in four elevational bands along four elevation gradients or transects encompassing 100-2200 m. A total of 12,533 trees belonging to 444 species were recorded. Diversity patterns along the elevation gradient and the explanatory power of independent variables were dependent on spatial scale (regional vs transect) and functional group (total vs late-successional or pioneer species). Diversity of all species and late-successional species (1 - proportion of pioneer species) showed a constant pattern at the regional and transect scales, with low predictive power of climatic variables and/or elevation. A linear decrease of either number or proportion of pioneer species diversity was observed with increasing elevation, which was correlated with temperature, rainfall, and human disturbance trends. Total species diversity showed an increase with rainfall of the warmest quarter, indicating a regional-level limiting effect of seasonality (drought duration). Yet the explanatory power of climatic and topographic variables was higher at the individual transect level than at the regional scale, suggesting the parallel but differential influence of evolutionary and geological history factors on diversification not so far studied to explain elevation patterns of species diversity in tropical mountain systems
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Papers by Mario González-espinosa