Browsing by Autor "Juan Carlos Licona"

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Abiotic and biotic drivers of biomass change in a Neotropical forest
(Wiley, 2017) Masha T. van der Sande; Marielos Peña‐Claros; Nataly Ascarrunz; E.J.M.M. Arets; Juan Carlos Licona; Marisol Toledo; Lourens Poorter
Summary Tropical forests play an important role in the global carbon cycle, but the drivers of net forest biomass change (i.e. net carbon sequestration) are poorly understood. Here, we evaluate how abiotic factors (soil conditions and disturbance) and biotic factors (forest structure, diversity and community trait composition) shape three important demographic processes (biomass recruitment, growth and mortality) and how these underlie net biomass change. To test this, we evaluated 9 years of biomass dynamics using 48 1‐ha plots in a Bolivian tropical moist forest, and measured for the most abundant species eight functional traits that are important for plant carbon gain and loss. Demographic processes were related to the abiotic and biotic factors using structural equation models. Variation in net biomass change across plots was mostly due to stand‐level mortality, but mortality itself could not be predicted at this scale. Contrary to expectations, we found that species richness and trait composition – which is an indicator for the mass‐ratio theory – had little effect on the demographic processes. Biomass recruitment (i.e. the biomass growth by recruiting trees) increased with higher resource availability (i.e. water and light) and with high species richness, probably because of increased resource use efficiency. Biomass growth of larger, established trees increased with higher sand content, which may facilitate root growth of larger trees to deeper soil layers. In sum, diversity and mass‐ratio are of limited importance for the productivity of this forest. Instead, in this moist tropical forest with a marked dry season, demographic processes are most strongly determined by soil texture, soil water availability and forest structure. Only by simultaneously evaluating multiple abiotic and biotic drivers of demographic processes, better insights can be gained into mechanisms playing a role in the carbon sequestration potential of tropical forests and natural systems in general.
ARE FUNCTIONAL TRAITS GOOD PREDICTORS OF DEMOGRAPHIC RATES? EVIDENCE FROM FIVE NEOTROPICAL FORESTS
(Wiley, 2008) Lourens Poorter; S. Joseph Wright‬; Horacio Paz; David D. Ackerly; Richard Condit; Guillermo Ibarra‐Manríquez; Kyle E. Harms; Juan Carlos Licona; Miguel Martínez‐Ramos; Susan J. Mazer
A central goal of comparative plant ecology is to understand how functional traits vary among species and to what extent this variation has adaptive value. Here we evaluate relationships between four functional traits (seed volume, specific leaf area, wood density, and adult stature) and two demographic attributes (diameter growth and tree mortality) for large trees of 240 tree species from five Neotropical forests. We evaluate how these key functional traits are related to survival and growth and whether similar relationships between traits and demography hold across different tropical forests. There was a tendency for a trade-off between growth and survival across rain forest tree species. Wood density, seed volume, and adult stature were significant predictors of growth and/or mortality. Both growth and mortality rates declined with an increase in wood density. This is consistent with greater construction costs and greater resistance to stem damage for denser wood. Growth and mortality rates also declined as seed volume increased. This is consistent with an adaptive syndrome in which species tolerant of low resource availability (in this case shade-tolerant species) have large seeds to establish successfully and low inherent growth and mortality rates. Growth increased and mortality decreased with an increase in adult stature, because taller species have a greater access to light and longer life spans. Specific leaf area was, surprisingly, only modestly informative for the performance of large trees and had ambiguous relationships with growth and survival. Single traits accounted for 9-55% of the interspecific variation in growth and mortality rates at individual sites. Significant correlations with demographic rates tended to be similar across forests and for phylogenetically independent contrasts as well as for cross-species analyses that treated each species as an independent observation. In combination, the morphological traits explained 41% of the variation in growth rate and 54% of the variation in mortality rate, with wood density being the best predictor of growth and mortality. Relationships between functional traits and demographic rates were statistically similar across a wide range of Neotropical forests. The consistency of these results strongly suggests that tropical rain forest species face similar trade-offs in different sites and converge on similar sets of solutions.
Assessing the extent of “conflict of use” in multipurpose tropical forest trees: A regional view
(Elsevier BV, 2013) Cristina Herrero‐Jáuregui; Manuel R. Guariguata; Dairón Cárdenas; Emilio Vilanova; M.C. Rubio Robles; Juan Carlos Licona; W. Nalvarte
Beyond reduced-impact logging: Silvicultural treatments to increase growth rates of tropical trees
(Elsevier BV, 2008) Marielos Peña‐Claros; Todd S. Fredericksen; Alejandro Alarcón; Geoffrey M. Blate; U. Choque; Claudio Leaño; Juan Carlos Licona; Bonifacio Mostacedo; William Pariona; Z. Villegas
Biodiversity and climate determine the functioning of Neotropical forests
(Wiley, 2017) Lourens Poorter; Masha T. van der Sande; E.J.M.M. Arets; Nataly Ascarrunz; Brian J. Enquist; Bryan Finegan; Juan Carlos Licona; Miguel Martínez‐Ramos; Lucas Mazzei; Jorge A. Meave
Abstract Aim Tropical forests account for a quarter of the global carbon storage and a third of the terrestrial productivity. Few studies have teased apart the relative importance of environmental factors and forest attributes for ecosystem functioning, especially for the tropics. This study aims to relate aboveground biomass (AGB) and biomass dynamics (i.e., net biomass productivity and its underlying demographic drivers: biomass recruitment, growth and mortality) to forest attributes (tree diversity, community‐mean traits and stand basal area) and environmental conditions (water availability, soil fertility and disturbance). Location Neotropics. Methods We used data from 26 sites, 201 1‐ha plots and >92,000 trees distributed across the Neotropics. We quantified for each site water availability and soil total exchangeable bases and for each plot three key community‐weighted mean functional traits that are important for biomass stocks and productivity. We used structural equation models to test the hypothesis that all drivers have independent, positive effects on biomass stocks and dynamics. Results Of the relationships analysed, vegetation attributes were more frequently associated significantly with biomass stocks and dynamics than environmental conditions (in 67 vs. 33% of the relationships). High climatic water availability increased biomass growth and stocks, light disturbance increased biomass growth, and soil bases had no effect. Rarefied tree species richness had consistent positive relationships with biomass stocks and dynamics, probably because of niche complementarity, but was not related to net biomass productivity. Community‐mean traits were good predictors of biomass stocks and dynamics. Main conclusions Water availability has a strong positive effect on biomass stocks and growth, and a future predicted increase in (atmospheric) drought might, therefore, potentially reduce carbon storage. Forest attributes, including species diversity and community‐weighted mean traits, have independent and important relationships with AGB stocks, dynamics and ecosystem functioning, not only in relatively simple temperate systems, but also in structurally complex hyper‐diverse tropical forests.
Climate and soil drive forest structure in Bolivian lowland forests
(Cambridge University Press, 2011) Marisol Toledo; Lourens Poorter; Marielos Peña‐Claros; Alfredo Alarcón; Julio Balcázar; Claudio Leaño; Juan Carlos Licona; Frans Bongers
Abstract: Climate is one of the most important factors determining variation in forest structure, but whether soils have independent effects is less clear. We evaluate how climate and soil independently affect forest structure, using 89 200 stems ≥ 10 cm dbh from 220 1-ha permanent plots distributed along environmental gradients in lowland Bolivia. Fifteen forest structural variables, related to vertical structure (forest height and layering), horizontal structure (basal area, median and the 99th percentile of the stem diameter and size-class distribution) and density of life forms (tree, palm and liana), were evaluated. Environmental variables were summarized in four multivariate axes, related to rainfall, temperature, soil fertility and soil texture. Multiple regression indicates that all structural variables were affected by one or more of the environmental axes, but the explained variation was generally low (median R 2 = 0.15). Rainfall and soil texture affected most forest structural variables (respectively 87% and 80%) and had qualitatively similar effects. This suggests that plant water availability, as determined by rainfall and soil water retention capacity, is the strongest driver of forest structure, whereas soil fertility was a weaker driver of forest structure, affecting 53% of the variables. Maximum forest height, palm density, total basal area and liana infestation showed the strongest responses to environmental variation (with R 2 ranging from 0.31–0.82). Forest height, palm density and total basal area increased with plant water availability, while liana infestation decreased with plant water availability. Therefore, multiple rather than single environmental factors must be used to explain the structure of tropical forests.
Climate is a stronger driver of tree and forest growth rates than soil and disturbance
(Wiley, 2010) Marisol Toledo; Lourens Poorter; Marielos Peña‐Claros; Alfredo Alarcón; Julio Balcázar; Claudio Leaño; Juan Carlos Licona; Oscar Llanque; Vincent Vroomans; Pieter A. Zuidema
Summary 1. Essential resources such as water, nutrients and light vary over space and time and plant growth rates are expected to vary accordingly. We examined the effects of climate, soil and logging disturbances on diameter growth rates at the tree and stand level, using 165 1‐ha permanent sample plots distributed across Bolivian tropical lowland forests. 2. We predicted that growth rates would be higher in humid than in dry forests, higher in nutrient‐rich than nutrient‐poor forests and higher in logged than non‐logged forests. 3. Across the 165 plots we found positive basal area increases at the stand level, which agree with the generally reported biomass increases in tropical forests. 4. Multiple regression analysis demonstrated that climate variables, in particular water availability, were the strongest drivers of tree growth. More rainfall, a shorter and less intense dry period and higher temperatures led to higher tree growth rates. 5. Tree growth increased modestly with soil fertility and basal area growth was greatest at intermediate soil fertility. Surprisingly, tree growth showed little or no relationship with total soil nitrogen or plant available soil phosphorus. 6. Growth rates increased in logged plots just after logging, but this effect disappeared after 6 years. 7. Synthesis . Climate is the strongest driver of spatial variation in tree growth, and climate change may therefore have large consequences for forest productivity and carbon sequestration. The negative impact of decreased rainfall and increased rainfall seasonality on tree growth might be partly offset by the positive impact of increased temperature in these forests.
Commercial Logging of Timber Species Enhances Amazon (Brazil) Nut Populations: Insights from Bolivian Managed Forests
(Multidisciplinary Digital Publishing Institute, 2021) Marlene Soriano; Pieter A. Zuidema; Cristina Barber; G.M.J. Mohren; Nataly Ascarrunz; Juan Carlos Licona; Marielos Peña‐Claros
A typical case of multiple-use forest management (MFM) in Southwestern Amazon is the commercial harvesting of Amazon or Brazil nut (Bertholletia excelsa) seeds and of timber of other tree species. Although the Amazon nut is the most important non-timber forest product (NTFP) in the Amazon basin, the species is under serious threat due to deforestation and may also be affected by overharvesting. However, selective logging of other tree species coexisting with Bertholletia may positively affect Bertholletia populations, thus enabling a special case for MFM. For this research, we investigated the impact of the intensity of Amazon nut harvesting and timber logging on Bertholletia populations in the Bolivian Amazon. We used demographic data from 72 two-hectare transects located within 24 community-based household forests varying in the intensity of nut collection (0–100%) and timber logging (0–15% of logging-disturbed forest area). Simulated Bertholletia population size increased with logging intensity but decreased with Amazon nut harvesting intensity. Bertholletia populations were projected to grow at the average MFM harvesting scenario tested: 57.4% of nut harvesting, 5.3% of logging-disturbed area (λ100 = 1.011). Our simulations also revealed that up to 89% of Amazon nut seeds can be harvested while sustaining Bertholletia populations, under 15% of logging-disturbed area, and applying liana cutting. Modest levels of timber logging and application of liana cutting may compensate for the negative effect of Amazon nut collection on Bertholletia populations for the next century. Our study demonstrates that Amazon nut and timber production could be combined in a sustainable MFM scheme, thus increasing the economic value of managed tropical forests and its promotion to reduce the increasing pressure by deforestation.
Cost and Efficiency of Cutting Lianas in a Lowland Liana Forest of Bolivia<sup>1</sup>
(Wiley, 2001) Diego R. Pérez‐Salicrup; Alberto Claros; Rudy Guzmán; Juan Carlos Licona; Fredy Ledezma; Michelle A. Pinard; Francis E. Putz
ABSTRACT Liana cutting is a commonly suggested silvicultural practice aimed at reducing the negative impacts of lianas on timber production, but few experimental studies have been conducted to evaluate the cost and efficiency of this practice. In this study, we estimated the cost of cutting lianas in 12 plots of 0.25 ha each in a densely liana‐infested forest of lowland Bolivia, and evaluated the efficiency of this silvicultural treatment in terms of the proportion of lianas missed, the density of resprouting liana stumps, and the number of liana‐infested trees after two years of an experimental liana treatment. The cost of cutting lianas in this forest by locally hired laborers was 23.6 (SE = 2.48) person‐hours/ha. Considering local cost of labor and the U.S.–Bolivian currency exchange rate at the time of the study, this figure translates to ca $15/ha. Liana density decreased from 2471 (SE = 104.3) to 130 (SE = 24.2) liana stems >2 cm/ha immediately after cutting, because 5.5 percent of lianas were left uncut (missed). Slender lianas were missed more often than lianas with large‐diameter stems. Liana species that grow 2–3 m before they start to twine were also frequently missed. Twenty‐two percent of liana stumps a2 cm sprouted after cutting. Liana stumps with larger diameters sprouted more than stumps with smaller diameters. Most liana stumps produced only two sprouts. Two years after cutting, 78 percent of trees had no living lianas in their crowns, in contrast to only 13 percent liana‐free trees in the control plots. Sixty‐four percent of trees still had hanging dead lianas two years after cutting, but only 23 percent of trees were reinvaded by lianas using dead liana stems as trellises. Liana cutting can efficiently reduce the number of lianas in liana‐infested forests, and the effects of cutting lianas last for at least two years; however, the treatment is expensive. Thus, we recommend that it is better to view liana cutting as a preventive activity to avoid liana infestation, rather than as a corrective measure after poor management. Liana cutting can be easily conducted along with other reduced‐impact logging practices. RESUMES El corte de lianas es una práctica de manejo comunmente recomendada para reducir los impactos negatives de las lianas en la producción forestal, pero existen pocos estudios experimentales que evaluen los costos y la eficiencia de dicha práctica. En este estudio estimamos el costo del corte de lianas en 12 parcelas de 0.25 ha cada una en un bosque densamente infestado de lianas en Bolivia, y evaluamos la eficiencia de este tratamiento en términos de la proporción de lianas no cortadas, de la densidad de lianas que rebrotan, y el número de árboles infestados con lianas dos años despues de un tratamiento del corte experimental de lianas. El costo de cortar lianas en este bosque por trabajadores locales fue de 23.6 (EE=2.48) horas‐persona/ha. Considerando el costo de labor y el intercambio monetario entre Bolivia y los EUA al tiempo del experimento, esta figura se traduce a ca 15 dólares EUA/ha. La densidad de lianas se redujo de 2471 (EE=104.3) a 130 (EE = 24.2) tallos de liana ≥2 cm/ha inmediatamente despues del corte, porque 5.5 por ciento de las lianas no se cortaron. Las lianas más delgadas fueron cortadas con mayor frequencia que las lianas más gruesas. Las especies de lianas que crecen
Damage to Brazil nut trees (Bertholletia excelsa) during selective timber harvesting in Northern Bolivia
(Elsevier BV, 2009) Manuel R. Guariguata; Juan Carlos Licona; Bonifacio Mostacedo; P. Cronkleton
Distribution patterns of tropical woody species in response to climatic and edaphic gradients
(Wiley, 2011) Marisol Toledo; Marielos Peña‐Claros; Frans Bongers; Alfredo Alarcón; Julio Balcázar; José Chuviña; Claudio Leaño; Juan Carlos Licona; Lourens Poorter
Summary 1. The analysis of species distribution patterns along environmental gradients is important for understanding the diversity and ecology of plants and species responses to climate change, but detailed data are surprisingly scarce for the tropics. 2. Here, we analyse the distribution of 100 woody species over 220 1‐ha forest plots distributed over an area of c. 160 000 km 2 , across large environmental gradients in lowland Bolivia and evaluate the relative importance of climate and soils in shaping species distribution addressing four multivariate environmental axes (rainfall amount and distribution, temperature, soil fertility and soil texture). 3. Although species abundance was positively related to species frequency (the number of plots in which the species is found), this relationship was rather weak, which challenges the view that most tropical forests are dominated at large scales by a few common species. 4. Species responded clearly to environmental gradients, and for most of the species (65%), climatic and soil conditions could explain most of the variation in occurrence ( R 2 > 0.50), which challenges the idea that most tropical tree species are habitat generalists. 5. Climate was a stronger driver of species distribution than soils; 91% of the species were affected by rainfall (distribution), 72% by temperature, 47% by soil fertility and 44% by soil texture. In contrast to our expectation, few species showed a typical unimodal response to the environmental gradients. 6. Synthesis . Tropical tree species specialize for different parts of the environmental gradients, and climate is a stronger driver of species distribution than soils. Because climate change scenarios predict increases in annual temperature and a stronger dry season for tropical forests, we may expect potentially large shifts in the distribution of tropical trees.
Driving factors of forest growth: a reply to Ferry <i>et al.</i> (2012)
(Wiley, 2012) Marisol Toledo; Lourens Poorter; Marielos Peña‐Claros; Alfredo Alarcón; Julio Balcázar; Claudio Leaño; Juan Carlos Licona; Oscar Llanque; Vincent Vroomans; Pieter A. Zuidema
Summary 1. In a recent paper, we analysed the effects of climate, soil and logging disturbance on tree and forest growth (Toledo et al. 2011a). We took advantage of one of the largest data sets in the Neotropics, consisting of 165 1‐ha plots and over 62 000 trees distributed over an area of c. 160 000 km 2 , across large environmental gradients in lowland Bolivia. The main findings were that climate was the strongest driver of spatial variation in tree growth, whereas soils had only a modest effect on growth and that the effect of logging disappeared after a few years. 2. Ferry et al. (2012) suggest that we underestimated the disturbance effects on growth because of a supposedly wrong coding of Time After Logging (TAL) for unlogged plots. Although we have good biological reasons why we coded TAL like we did, we checked Ferry et al. ’s suggestions for recoding and found no differences in variables that significantly explained tree and forest growth. We agree, however, that for future research, it is important to go beyond simple descriptors such as time after logging and basal area logged, to better describe the variation in logging impact found in areas under forest management. 3. Ferry et al. claim that we did not define basal area growth properly. We believe this is a semantic issue, as we clearly defined basal area growth as the net change in basal area. This net basal area change in Bolivian forests is indeed relatively high compared to other studies, which may be attributed to the higher soil fertility and biogeographic differences in species composition and their traits. 4. Synthesis . Many apparent discrepancies in the ecological literature arise because tropical forest ecologists tend to see the world from the perspective of their ‘own’ forest (despite clear biogeographic differences) and try to capture the same ecological processes using different variables and measurement protocols. To advance our understanding and go beyond single‐case studies, we need to assemble large databases, quantify forest dynamics and disturbances in similar ways, be aware of differences among forests and analyse environmental dose–response curves.
Fates of trees damaged by logging in Amazonian Bolivia
(Elsevier BV, 2015) Alexander Shenkin; Benjamin M. Bolker; Marielos Peña‐Claros; Juan Carlos Licona; Francis E. Putz
Gene flow in an overexploited population of Swietenia macrophylla King (Meliaceae) in the Bolivian Amazon
(De Gruyter Open, 2012) Alexandre Magno Sebbenn; Juan Carlos Licona; Bonifacio Mostacedo; Бернд Деген
Abstract Pollen and seed movement among and within populations connect individuals and populations, and therefore are among the most important evolutionary processes determining the genetic structure of populations. Seven microsatellite loci were used to investigate the realized pollen dispersal and intra-population spatial genetic structure (SGS) in four permanent plots located in an overexploited big-leaf mahogany (Swietenia macrophylla King) population in the Bolivian Amazon. All adult trees found in the plots were mapped, sampled and genotyped. Seedlings were sampled below the canopy of reproductive trees. Private alleles in the sub-population of the adults and the seedlings were observed. The observed heterozygosity was significantly lower and fixation index was significantly higher for the seedlings (H o =0.697, F=0.068) compared to the adults (H o =0.761, F=-0.023). In one plot, seed immigration was observed (18%). Realized pollen immigration ranged among the plots from zero to 41% and selfing ranged from zero to 5.8%. We observed an average pollen dispersal distance from 75 to 255 m, with the maximum reaching 576 m. We found a significant SGS up to 150 m, showing that near neighbour individuals are relatives. The observed data on pollen- and seed dispersal provides important information for the sustainable management of the endangered mahogany species.
Interactive effects of tree size, crown exposure and logging on drought-induced mortality
(Royal Society, 2018) Alexander Shenkin; Benjamin M. Bolker; Marielos Peña‐Claros; Juan Carlos Licona; Nataly Ascarrunz; Francis E. Putz
Large trees in the tropics are reportedly more vulnerable to droughts than their smaller neighbours. This pattern is of interest due to what it portends for forest structure, timber production, carbon sequestration and multiple other values given that intensified El Niño Southern Oscillation (ENSO) events are expected to increase the frequency and intensity of droughts in the Amazon region. What remains unclear is what characteristics of large trees render them especially vulnerable to drought-induced mortality and how this vulnerability changes with forest degradation. Using a large-scale, long-term silvicultural experiment in a transitional Amazonian forest in Bolivia, we disentangle the effects of stem diameter, tree height, crown exposure and logging-induced degradation on risks of drought-induced mortality during the 2004/2005 ENSO event. Overall, tree mortality increased in response to drought in both logged and unlogged plots. Tree height was a much stronger predictor of mortality than stem diameter. In unlogged plots, tree height but not crown exposure was positively associated with drought-induced mortality, whereas in logged plots, neither tree height nor crown exposure was associated with drought-induced mortality. Our results suggest that, at the scale of a site, hydraulic factors related to tree height, not air humidity, are a cause of elevated drought-induced mortality of large trees in unlogged plots. This article is part of a discussion meeting issue ‘The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications'.
Invasion of Non-Commercial Tree Species After Selection Logging in a Bolivian Tropical Forest
(Taylor & Francis, 2000) Todd S. Fredericksen; Juan Carlos Licona
Abstract Single-tree selection logging will likely result in a 4.3% loss in the relative abundance and a 4.1% loss in basal area of trees of commercial species in one cutting cycle due to their removal by harvesting combined with their potential recolonization of only 31% of logging gaps in a Bolivian tropical dry forest. Densities of the most valuable species, Amburana cearensis and Cedrela fissilis, were particularly reduced by logging. To sustain the current harvesting rate, uses need to be developed for more non-commercial species and/or silvicul-tural treatments employed that increase regeneration of commercial species and remove non-commercial species using timber stand improvement techniques.
Natural regeneration and liberation of timber species in logging gaps in two Bolivian tropical forests
(Elsevier BV, 2003) William Pariona; Todd S. Fredericksen; Juan Carlos Licona
Patterns and Determinants of Floristic Variation across Lowland Forests of Bolivia
(Wiley, 2010) Marisol Toledo; Lourens Poorter; Marielos Peña‐Claros; Alfredo Alarcón; Julio Balcázar; José Chuviña; Claudio Leaño; Juan Carlos Licona; Hans ter Steege; Frans Bongers
Floristic variation is high in the Neotropics, but little is known about the factors shaping this variation at the mesoscale. We examined floristic composition and its relationship with environmental factors across 220 1-ha permanent plots in tropical lowland Bolivia. For each plot, abundance of 100 species (93 tree and 7 palm species ≥10 cm diam) was obtained. Climatic data, related to rainfall seasonality and temperature, were interpolated from all available weather stations in the region, and soil properties, related to texture and fertility, were obtained for each plot. Floristic variation was strongly associated with differences in water availability and temperature, and therefore the climatic gradient shaped floristic variation more strongly than the edaphic gradient. Detrended correspondence analysis ordination divided lowland Bolivia primarily into two major groups (Southern Chiquitano region vs. the Amazon region) and a multiple response permutation procedure distinguished five floristic regions. Overall, the tested environmental variables differed significantly among the five regions. Using indicator species analysis, we distinguished 82 strong indicator species, which had significant environmental preferences for one floristic region. These species can be used as indicators of environmental conditions or to determine which floristic region a certain forest belongs. Given the predicted decreases in rainfall and increases in temperature for tropical lowland forests, our gradient approach suggests that species composition may shift drastically with climate change. Abstract in Spanish is available at http://www.blackwell-synergy.com/loi/btp.
Soil Effects on Forest Structure and Diversity in a Moist and a Dry Tropical Forest
(Wiley, 2011) Marielos Peña‐Claros; Lourens Poorter; Alfredo Alarcón; Geoffrey M. Blate; U. Choque; Todd S. Fredericksen; M. Joaquin Justiniano; Claudio Leaño; Juan Carlos Licona; William Pariona
ABSTRACT Soil characteristics are important drivers of variation in wet tropical forest structure and diversity, but few studies have evaluated these relationships in drier forest types. Using tree and soil data from 48 and 32 1 ha plots, respectively, in a Bolivian moist and dry forest, we asked how soil conditions affect forest structure and diversity within each of the two forest types. After correcting for spatial effects, soil‐vegetation relationships differed between the dry and the moist forest, being strongest in the dry forest. Furthermore, we hypothesized that soil nutrients would play a more important role in the moist forest than in the dry forest because vegetation in the moist forest is less constrained by water availability and thus can show its full potential response to soil fertility. However, contrary to our expectations, we found that soil fertility explained a larger number of forest variables in the dry forest (50 percent) than in the moist forest (17 percent). Shannon diversity declined with soil fertility at both sites, probably because the most dominant, shade‐tolerant species strongly increased in abundance as soil fertility increased.
Tree mortality and vine proliferation following a wildfire in a subhumid tropical forest in eastern Bolivia
(Elsevier BV, 1999) Michelle A. Pinard; Francis E. Putz; Juan Carlos Licona