Experiment 3-Abundance. Data on cumulative number of seedlings established over time from the nat... more Experiment 3-Abundance. Data on cumulative number of seedlings established over time from the natural seed bank in sites of single vs. recurrent defecation
Experiment 2. Data on seedlings established from natural seeds buried at three depths and three t... more Experiment 2. Data on seedlings established from natural seeds buried at three depths and three treatment levels of feces and beetle manipulation
Experiment 1. Data on vertical re-distribution of artificial seeds buried in the soil at three de... more Experiment 1. Data on vertical re-distribution of artificial seeds buried in the soil at three depths
Dung beetles relocate vertebrate feces under the soil surface, and this behavior has many ecologi... more Dung beetles relocate vertebrate feces under the soil surface, and this behavior has many ecological consequences. In tropical forests, for example, seeds defecated by mammals that are subsequently buried by dung beetles are less likely to suffer predation. While the effects of dung beetles on the fate of defecated seeds have been relatively well studied, their effect on seeds already buried in the soil has not. To contribute to fill this gap we designed a study with three objectives: (1) Describe the vertical re-distribution of soil seeds that occurs due to dung beetle activity; (2) Determine if beetle activity favors establishment of seedlings from the soil seed bank; and (3) Determine if the effect of dung beetles is stronger in sites of recurrent mammal defecation. We carried out three complementary field experiments, one with artificial seeds (plastic beads) of three sizes buried at known depths, one with two species of seeds buried at those same depths, and one with the natural soil seed bank in sites of single vs. recurrent defecation. Buried beads were moved by dung beetles along the vertical axis, both upwards (9.5%) and downwards (11.5%); smaller beads were more frequently moved downwards while the contrary occurred for larger beads. Dung beetle activity caused an increase in seedling establishment, both from experimentally buried seeds and from the natural seed bank. Defecation recurrence had no effect on seedling establishment. We conclude that dung beetle activity affects seed bank dynamics with important consequences for seedling establishment in tropical forests
All five datasets from this study correspond to field observations collected for seedlings of six... more All five datasets from this study correspond to field observations collected for seedlings of six tree species (Brosimum alicastrum, Calophyllum brasiliense, Cymbopetalum baillonii, Diospyros digyna, Omphalea oleifera and Poulsenia armata) in a tropical rainforest (Los Tuxtlas, Mexico). We estimated the concentrations of foliar nitrogen (N) and phosphorus (P), resource allocation (the ratio of biomass allocated to shoot vs root), seedling survival, and growth. Experimental seedlings were subject to three treatment levels: (a) feces added and beetles active, (b) feces added and beetles excluded, and (c) no feces added (and consequently no beetles active). We analyzed data at two levels: community (all plant species together) and individual species. For resource allocation (ESM_Dataset1_RootShoot) we weighed aerial parts (stem and leaves) and roots, separately, and calculated the root/shoot biomass ratio for each seedling. For foliar nutrients (ESM_Dataset2_FoliarNutrients) we obtaine...
Abstract Patch size is considered a major driver of species diversity in fragmented landscapes. Y... more Abstract Patch size is considered a major driver of species diversity in fragmented landscapes. Yet, assemblages of forest-dependent species, such as tropical arboreal mammals, can also depend on vegetation characteristics within the patch, i.e. patch quality. To test this, we assessed the influence of patch size and quality (measured through six attributes of vegetation structure) on arboreal mammals in 20 forest patches in the Lacandona rainforest – a biodiversity hotspot in the Mesoamerican Biological Corridor. We placed camera traps in 100 trees and registered arboreal mammals for one year. We used generalized linear models with a multimodel averaging approach and a distance-based redundancy analysis to identify the relative importance of patch size and quality on arboreal mammal diversity and composition. Species diversity was mainly and positively influenced by tree basal area – a vegetation attribute indicative of older and better-preserved forests – while species composition was driven by both patch size and quality. Patch size was negatively related to the abundance of kinkajous and Deppei’s squirrels, likely due to a higher density (and detectability) of individuals in small patches. The abundance of kinkajous and Deppei’s squirrels was lower in patches with higher tree density – an attribute typically related to forest disturbance. Therefore, to effectively preserve this highly endangered and ecologically relevant group of mammals, both patch size and quality should be considered, paying special attention to the conservation of large trees.
Dry tropical forests have a high diversity of local tree species with forage potential; these tre... more Dry tropical forests have a high diversity of local tree species with forage potential; these trees can be a strategic resource in the design of more sustainable livestock systems. The forage potential of sixteen selected tree species was evaluated in silvopastoral systems in Chamela, Jalisco, Mexico. Available biomass and nutritional quality of leaves and fruits consumed by cattle were estimated in the rainy and dry seasons. General and specific allometric models were generated in order to estimate potential biomass. Average available foliage was 0.96 ± 4.9 kg DM/tree, with a crude protein content of 148 ± 46 g/kg. Average biomass of fruits was 1.8 ± 3.7 kg DM/tree, with a crude protein content of 110 ± 54 g/kg. The best allometric models for foliage include canopy cover as a predictor, and canopy cover, height and base area in the case of fruits. Some of the evaluated species, such as Leucaena lanceolata, Guazuma ulmifolia, Ceasalpinia coriaria and Hura polyandra have outstanding forage potential, as they produce important amounts of foliage and fruits with a high nutritive value. They can therefore be recommended for use in livestock systems of the region to diversify grasslands and other agroforestry practices. Allometric models and nutritional analyses proved essential tools to estimate the potential contribution of trees to livestock feeding in the dry tropics, therefore assisting decision making in terms of the most appropriate species for silvopastoral systems.
Background/Question/Methods Although a plethora of studies have reported forest biomass or carbon... more Background/Question/Methods Although a plethora of studies have reported forest biomass or carbon accumulation during succession in tropical forests using a chronosequence approach, few of them have tested which are the attributes of the tree community associated to recovery. Previous work suggest that fallow age, structural attributes such as basal area or mean height, or functional attributes such as wood density and maximum size of the species are associated to carbon stocks. However, neither study has tested if carbon recovery inferred from chronosequences matches real-time change in carbon stocks, and if those forest attributes associated to carbon stocks are the same predicting real-time changes. In this study we answer this question using a system of twelve permanent plot sites in different successional stages from a tropical dry forest located on the Mexican pacific coast. For each site we estimated carbon in aboveground living biomass (ABC) for three repeated censuses (2004...
Experiment 3-Abundance. Data on cumulative number of seedlings established over time from the nat... more Experiment 3-Abundance. Data on cumulative number of seedlings established over time from the natural seed bank in sites of single vs. recurrent defecation
Experiment 2. Data on seedlings established from natural seeds buried at three depths and three t... more Experiment 2. Data on seedlings established from natural seeds buried at three depths and three treatment levels of feces and beetle manipulation
Experiment 1. Data on vertical re-distribution of artificial seeds buried in the soil at three de... more Experiment 1. Data on vertical re-distribution of artificial seeds buried in the soil at three depths
Dung beetles relocate vertebrate feces under the soil surface, and this behavior has many ecologi... more Dung beetles relocate vertebrate feces under the soil surface, and this behavior has many ecological consequences. In tropical forests, for example, seeds defecated by mammals that are subsequently buried by dung beetles are less likely to suffer predation. While the effects of dung beetles on the fate of defecated seeds have been relatively well studied, their effect on seeds already buried in the soil has not. To contribute to fill this gap we designed a study with three objectives: (1) Describe the vertical re-distribution of soil seeds that occurs due to dung beetle activity; (2) Determine if beetle activity favors establishment of seedlings from the soil seed bank; and (3) Determine if the effect of dung beetles is stronger in sites of recurrent mammal defecation. We carried out three complementary field experiments, one with artificial seeds (plastic beads) of three sizes buried at known depths, one with two species of seeds buried at those same depths, and one with the natural soil seed bank in sites of single vs. recurrent defecation. Buried beads were moved by dung beetles along the vertical axis, both upwards (9.5%) and downwards (11.5%); smaller beads were more frequently moved downwards while the contrary occurred for larger beads. Dung beetle activity caused an increase in seedling establishment, both from experimentally buried seeds and from the natural seed bank. Defecation recurrence had no effect on seedling establishment. We conclude that dung beetle activity affects seed bank dynamics with important consequences for seedling establishment in tropical forests
All five datasets from this study correspond to field observations collected for seedlings of six... more All five datasets from this study correspond to field observations collected for seedlings of six tree species (Brosimum alicastrum, Calophyllum brasiliense, Cymbopetalum baillonii, Diospyros digyna, Omphalea oleifera and Poulsenia armata) in a tropical rainforest (Los Tuxtlas, Mexico). We estimated the concentrations of foliar nitrogen (N) and phosphorus (P), resource allocation (the ratio of biomass allocated to shoot vs root), seedling survival, and growth. Experimental seedlings were subject to three treatment levels: (a) feces added and beetles active, (b) feces added and beetles excluded, and (c) no feces added (and consequently no beetles active). We analyzed data at two levels: community (all plant species together) and individual species. For resource allocation (ESM_Dataset1_RootShoot) we weighed aerial parts (stem and leaves) and roots, separately, and calculated the root/shoot biomass ratio for each seedling. For foliar nutrients (ESM_Dataset2_FoliarNutrients) we obtaine...
Abstract Patch size is considered a major driver of species diversity in fragmented landscapes. Y... more Abstract Patch size is considered a major driver of species diversity in fragmented landscapes. Yet, assemblages of forest-dependent species, such as tropical arboreal mammals, can also depend on vegetation characteristics within the patch, i.e. patch quality. To test this, we assessed the influence of patch size and quality (measured through six attributes of vegetation structure) on arboreal mammals in 20 forest patches in the Lacandona rainforest – a biodiversity hotspot in the Mesoamerican Biological Corridor. We placed camera traps in 100 trees and registered arboreal mammals for one year. We used generalized linear models with a multimodel averaging approach and a distance-based redundancy analysis to identify the relative importance of patch size and quality on arboreal mammal diversity and composition. Species diversity was mainly and positively influenced by tree basal area – a vegetation attribute indicative of older and better-preserved forests – while species composition was driven by both patch size and quality. Patch size was negatively related to the abundance of kinkajous and Deppei’s squirrels, likely due to a higher density (and detectability) of individuals in small patches. The abundance of kinkajous and Deppei’s squirrels was lower in patches with higher tree density – an attribute typically related to forest disturbance. Therefore, to effectively preserve this highly endangered and ecologically relevant group of mammals, both patch size and quality should be considered, paying special attention to the conservation of large trees.
Dry tropical forests have a high diversity of local tree species with forage potential; these tre... more Dry tropical forests have a high diversity of local tree species with forage potential; these trees can be a strategic resource in the design of more sustainable livestock systems. The forage potential of sixteen selected tree species was evaluated in silvopastoral systems in Chamela, Jalisco, Mexico. Available biomass and nutritional quality of leaves and fruits consumed by cattle were estimated in the rainy and dry seasons. General and specific allometric models were generated in order to estimate potential biomass. Average available foliage was 0.96 ± 4.9 kg DM/tree, with a crude protein content of 148 ± 46 g/kg. Average biomass of fruits was 1.8 ± 3.7 kg DM/tree, with a crude protein content of 110 ± 54 g/kg. The best allometric models for foliage include canopy cover as a predictor, and canopy cover, height and base area in the case of fruits. Some of the evaluated species, such as Leucaena lanceolata, Guazuma ulmifolia, Ceasalpinia coriaria and Hura polyandra have outstanding forage potential, as they produce important amounts of foliage and fruits with a high nutritive value. They can therefore be recommended for use in livestock systems of the region to diversify grasslands and other agroforestry practices. Allometric models and nutritional analyses proved essential tools to estimate the potential contribution of trees to livestock feeding in the dry tropics, therefore assisting decision making in terms of the most appropriate species for silvopastoral systems.
Background/Question/Methods Although a plethora of studies have reported forest biomass or carbon... more Background/Question/Methods Although a plethora of studies have reported forest biomass or carbon accumulation during succession in tropical forests using a chronosequence approach, few of them have tested which are the attributes of the tree community associated to recovery. Previous work suggest that fallow age, structural attributes such as basal area or mean height, or functional attributes such as wood density and maximum size of the species are associated to carbon stocks. However, neither study has tested if carbon recovery inferred from chronosequences matches real-time change in carbon stocks, and if those forest attributes associated to carbon stocks are the same predicting real-time changes. In this study we answer this question using a system of twelve permanent plot sites in different successional stages from a tropical dry forest located on the Mexican pacific coast. For each site we estimated carbon in aboveground living biomass (ABC) for three repeated censuses (2004...
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