Effects of Forest Fragmentation on the Vertical Stratification of Neotropical Bats

Vertical stratification is a key component of the biological complexity of rainforests. Understanding community- and species-level responses to disturbance across forest strata is paramount for evidence-based conservation and management. However, even for bats, known to extensively explore multiple layers of the complex three-dimensional forest space, studies are biased towards understory-based surveys and only few assessments of vertical stratification were done in fragmented landscapes. Using both ground and canopy mist-nets, we investigated how the vertical structure of bat assemblages is influenced by forest fragmentation in the experimentally fragmented landscape of the Biological Dynamics of Forest Fragments Project, Central Amazon, Brazil. Over a three year-period, we captured 3077 individuals of 46 species in continuous forest (CF) and in 1, 10 and 100 ha forest fragments. In both CF and forest fragments, the upper forest strata sustained more diverse bat assemblages than the equivalent understory layer, and the midstory layers had significantly higher bat abundance in fragments than in CF. Artibeus lituratus and Rhinophylla pumilio exhibited significant shifts in their vertical stratification patterns between CF and fragments (e.g., R. pumilio was more associated with the upper strata in fragments than in CF). Altogether, our study suggests that fragmentation modulates the vertical stratification of bat assemblages.

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Vertical stratification in bat assemblages of the Atlantic Forest of south-eastern Brazil

Journal of Tropical Ecology ◽

10.1017/s026646741700027x ◽

2017 ◽

Vol 33 (5) ◽

pp. 299-308 ◽

Cited By ~ 7

Author(s):

Renato Gregorin ◽

Enrico Bernard ◽

Karina Weiser Lobão ◽

Luciany Ferreira Oliveira ◽

Felipe Santana Machado ◽

...

Keyword(s):

Tropical Forests ◽

Atlantic Forest ◽

Relative Abundance ◽

Resource Partitioning ◽

Three Dimensional ◽

Vertical Stratification ◽

Forest Canopies ◽

Eastern Brazil ◽

Forest Strata ◽

Artibeus Lituratus

Abstract:Tropical forests are three-dimensional spaces with species and resources heterogeneously distributed. The vertical stratification of tropical forest biotas has been observed for several organisms and regions, but, surprisingly, the vertical structuring of large areas of important tropical forests, such as Brazil's Atlantic Forest, remains poorly studied. Here, we addressed the use of different Atlantic Forest strata by bats, comparing ensemble composition and relative abundance between the understorey and the canopy. A total of 618 bats belonging to 31 species and four families were recorded, including 11 species of frugivores and seven species of gleaning insectivores, the two trophic guilds predominantly represented in our sampling. Fifteen species were captured exclusively in the canopy, and six exclusively in the understorey, and many of those species were represented by a low number of captures (<5). The bat species composition, richness and relative abundance between canopy and understorey strata varied.Chiroderma villosumwas exclusively captured in the canopy,Artibeus lituratuswas netted predominantly in the canopy andCarollia perspicillataandDesmodus rotunduswere mostly captured in the understorey. Although processes such as resource partitioning between species and ecomorphological constraints may explain the differential use of forest strata, this remains little understood because of the scarcity of data for the Atlantic forest canopies.

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Effects of forest fragmentation on frugivorous and nectarivorous bats in French Guiana

Journal of Tropical Ecology ◽

10.1017/s026646749900098x ◽

1999 ◽

Vol 15 (4) ◽

pp. 515-534 ◽

Cited By ~ 104

Author(s):

Jean-François Cosson ◽

Jean-Marc Pons ◽

Didier Masson

Keyword(s):

Forest Fragmentation ◽

French Guiana ◽

Home Range Size ◽

Foraging Strategies ◽

Forest Fragments ◽

Fruit Bat ◽

Continuous Forest ◽

Study Sites ◽

Genetic Structures ◽

And Control

The effects of tropical forest fragmentation on frugivorous and nectarivorous bats were studied on recent islands created by the flooding of a dam in French Guiana. Study sites include forest islands isolated by water, and control plots in nearby continuous forest. Studies began 1y before the onset of forest fragmentation and encompassed the first 3y after flooding. Forest fragmentation greatly modified the diversity and abundance of bats. Changes occurred more rapidly in the smallest fragments than in the largest one, and trends were remarkably similar among all the studied islands. Bat captures in islands were characterised by the scarcity of understorey frugivores. Differences in home range size and foraging strategies may explain why understorey fruit bat species are more sensitive to fragmentation than canopy ones. Changes in the frugivorous bat community may have indirect consequences on both the demographic and the genetic structures of plant populations inside forest fragments.

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Nonconstituent species in soil seed banks as indicators of anthropogenic disturbance in forest fragments

Canadian Journal of Forest Research ◽

10.1139/x06-137 ◽

2006 ◽

Vol 36 (9) ◽

pp. 2300-2316 ◽

Cited By ~ 8

Author(s):

Luxiang Lin ◽

Min Cao ◽

Yongtao He ◽

Jerry M Baskin ◽

Carol C Baskin

Keyword(s):

Forest Fragmentation ◽

Forest Ecosystems ◽

Biological Diversity ◽

Seed Banks ◽

Soil Samples ◽

Southwestern China ◽

Native Forest ◽

Forest Fragments ◽

Soil Seed Banks ◽

Continuous Forest

Forest fragmentation is prevalent in regions with high human population density, but also with high biological diversity, such as southwestern China. Predicting potential changes in species composition in native forest ecosystems resulting from forest fragmentation is an important approach in assessing forest ecosystems and sustainable management of forests. The term nonconstituent species is proposed for plant species that occur in a natural landscape but are not native to it. We hypothesized that fragmentation of continuous forests significantly increases both the richness and the size of soil seed banks of nonconstituent species. To test our hypothesis we compared soil seed banks in three small fragments and one large tract of subtropical evergreen broad-leaved forest in Yunnan Province, southwestern China. In total, 249 species were identified in all soil samples from the four sites. Nonconstituent species represented 36.4%–61.5% of the total taxa and 33.8%–59.6% of total germinants from soil samples in the three forest fragments, but only 3.7%–7.9% of total taxa and 7.5%–9.4% of total germinants from soil samples in the continuous forest tract. Both richness and size of soil seed banks of nonconstituent species were greater under forest fragments than under continuous forest. A majority of nonconstituent species were native weeds and annual herbs with wind-dispersed seeds; most were present in soil seed banks but not in aboveground vegetation. We suggest that nonconstituent species in soil seed banks could be used as an indicator species group for assessing human disturbance. If so, the richness and size of soil seed banks of nonconstituent species could play an important role in quantifying disturbance in forests.

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Gap-crossing by Wood Thrushes (Hylocichla mustelina)in a fragmented landscape

Canadian Journal of Zoology ◽

10.1139/z11-090 ◽

2011 ◽

Vol 89 (11) ◽

pp. 1091-1097 ◽

Cited By ~ 7

Author(s):

T. MacIntosh ◽

B.J.M. Stutchbury ◽

M.L. Evans

Keyword(s):

Radio Telemetry ◽

Fragmented Landscape ◽

Forest Fragments ◽

Forest Fragment ◽

Hylocichla Mustelina ◽

Continuous Forest ◽

Migratory Songbirds ◽

Gap Crossing ◽

Wood Thrushes ◽

Gap Width

We used radio-telemetry to study the movement patterns of Wood Thrushes ( Hylocichla mustelina (J.F. Gmelin, 1789)) occupying small forest fragments (<5 ha) to examine gap-crossing between fragments and edge use within fragments. We found that 82% (8/11) of males and 33% (2/6) of females made at least one foray off of its resident forest fragment and we documented a total of 26 off-fragment forays (n = 79 h tracking). Males spent, on average, 23.5% of their time off their fragment, while females were gone 12.8% of the time tracked. Most forays were >150 m in distance and foray rate to adjacent fragments declined with increasing gap width. Males on fragments spent more time off their territory (23.5%) and traveled farther (392 m) than males occupying territories within a continuous forest (4.8% and 99 m, respectively). In fragments, 10 out of 17 individuals spent >80% of their time within 20 m of the fragment edge and edge use was significantly more than expected based on the amount of edge available in each fragment. This study adds to the growing evidence for migratory songbirds that during the breeding season, forest fragmentation may increase rather than impede daily movements.

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Continuous forest has greater taxonomic, functional and phylogenetic plant diversity than an adjacent naturally fragmented forest

Journal of Tropical Ecology ◽

10.1017/s0266467414000194 ◽

2014 ◽

Vol 30 (4) ◽

pp. 323-333 ◽

Cited By ~ 18

Author(s):

Miguel A. Munguía-Rosas ◽

Selmy G. Jurado-Dzib ◽

Candy R. Mezeta-Cob ◽

Salvador Montiel ◽

Armando Rojas ◽

...

Keyword(s):

Tropical Forest ◽

Forest Fragmentation ◽

Plant Diversity ◽

Phylogenetic Diversity ◽

Taxonomic Diversity ◽

Evergreen Forest ◽

Forest Fragments ◽

Fragmented Forest ◽

Continuous Forest ◽

Functional And Phylogenetic Diversity

Abstract:Several studies have evaluated the short-term effects of tropical forest fragmentation on plant taxonomic diversity, while only a few have evaluated its effects on functional or phylogenetic diversity. To our knowledge no study has looked at the long-term consequences of tropical forest fragmentation on the three main components of plant diversity simultaneously: taxonomic, functional and phylogenetic diversity. We sampled the vascular flora using belt transects (50 × 4 m) in a continuous tropical semi-evergreen forest (16 transects) and in an adjacent naturally fragmented forest (fragments of 1.7-My-old semi-evergreen forest immersed in a mangrove/sedge matrix) (18 transects), and compared their taxonomic, functional and phylogenetic plant diversity. There were 36 species in the continuous forest and 28 in the fragmented forest. Continuous forest was taxonomically more diverse (25%) than the fragmented forest. All functional diversity metrics were greater (6–33%) in the continuous than in the fragmented forest. Phylogenetic diversity was 19% greater and phylogenetically more overdispersed in the continuous forest than in the fragmented forest. The results suggest that in the fragmented forest not only is taxonomic plant diversity lower, but functional and phylogenetic diversity are as well. The negative effects of forest fragmentation on plant diversity seem to be chronic.

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Delayed effects of climate on vital rates lead to demographic divergence in Amazonian forest fragments

10.1101/2021.06.28.450186 ◽

2021 ◽

Author(s):

Eric R Scott ◽

Emilio Miguel Bruna ◽

María Uriarte

Keyword(s):

Amazon Basin ◽

Life History Stage ◽

Fragmented Landscape ◽

Forest Fragments ◽

Vital Rates ◽

Climate Data ◽

Plant Populations ◽

Delayed Effects ◽

Continuous Forest ◽

Flowering Probability

Deforestation often results in landscapes where remaining forest habitat is highly fragmented, with remnants of different sizes embedded in an often highly contrasting matrix. Local extinction of species from individual fragments is common, but the demographic mechanisms underlying these extinctions are poorly understood. It is often hypothesized that altered environmental conditions in fragments drive declines in reproduction, recruitment, or survivorship. The Amazon basin, in addition to experiencing continuing fragmentation, is warming and experiencing changes in precipitation leading to altered frequency and intensity of droughts and unusually wet periods. Whether plant populations in tropical forest fragments are particularly susceptible to extremes in precipitation remains unclear. Most studies of plants in fragments are relatively short (1-6 years), focus on a single life-history stage, and often do not compare to populations in continuous forest. Even fewer studies consider delayed effects of climate on demographic vital rates despite the importance of delayed effects in studies that consider them. Using a decade of demographic and climate data from an experimentally fragmented landscape in the Central Amazon, we assess the effects of climate on populations of an understory herb (Heliconia acuminata, Heliconiaceae). We used distributed lag non-linear models to understand the delayed effects of temperature and precipitation on survival, growth, and flowering. We detected delayed effects of climate up to 36 months. Drought two dry seasons prior to the February census decreased survival and increased flowering probability while drought in the wet season a year prior to the census decreased flowering probability and increased growth. The effects of extremes in precipitation on survival and growth were more pronounced in forest fragments compared to continuous forest. The complex delayed effects of climate and habitat fragmentation in our study point to the importance of long-term demography experiments in understanding the effects of anthropogenic change on plant populations.

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EXOTIC PALMS THREATENS NATIVE PALMS: A RISK TO PLANT BIODIVERSITY OF ATLANTIC FOREST

Revista Árvore ◽

10.1590/1806-90882018000200016 ◽

2018 ◽

Vol 42 (2) ◽

Author(s):

Tiago Monteiro Condé ◽

Fernando da Silva ◽

Agostinho Lopes de Souza ◽

Helio Garcia Leite ◽

Eder Aparecido Garcia ◽

...

Keyword(s):

Atlantic Forest ◽

Secondary Forest ◽

Control Measures ◽

Anthropogenic Pressure ◽

Forest Fragments ◽

Palm Trees ◽

Continuous Forest ◽

High Germination ◽

Palm Species ◽

Forest Strata

ABSTRACT Invasive plants can profoundly modify physical and biological characteristics of their new environments, especially when such habitats are already fragmented and reduced by anthropogenic pressure, such as the Atlantic Forest of Brazil. Here, we hypothesized that exotic palms successfully establish among the natural Euterpe edulis populations through a continuous propagule input by avifauna, high germination rates, and rapid growth. As a result, the native palm is experiencing decline and may be threatened with extinction. Beginning in 2007, we conducted a continuous forest inventory (FCI) every three years in the primary and secondary forest fragments of Viçosa, Minas Gerais. We use a Markov matrix to project future distributions of palm trees. The secondary forest contained three exotic palm species: Archontophoenix alexandrae, Livistona chinensis, and Arenga caudata. The first palm is a serious risk to natural E. edulis populations in the Atlantic because of frequent interactions with birds, rapid germination, and aggressive colonization in the lower to medium vertical forest strata. Currently, natural E. edulis populations are viable and sustainable, capable of regeneration, growth, and fruiting, their communities maintain continuous gene flow, dominating vertical forest strata compared with exotic palms. However, exotic palms should be monitored and control measures should be analyzed, especially in areas with A. alexandrae populations.

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Influence of landscape structure on the abundance of Desmodus rotundus (Geoffroy 1810) in northeastern Yucatan, Mexico

Ecosistemas y Recursos Agropecuarios ◽

10.19136/era.a6n17.1968 ◽

2019 ◽

Vol 6 (17) ◽

pp. 263

Author(s):

Beatriz Bolívar-Cimé ◽

Rafael Flores-Peredo ◽

Scarlett Aislinn García-Ortíz ◽

Rene Murrieta-Galindo ◽

Javier Laborde

Keyword(s):

Forest Fragmentation ◽

Forest Cover ◽

Landscape Heterogeneity ◽

Negative Impact ◽

Fragmented Landscape ◽

Forest Fragments ◽

Semideciduous Forest ◽

Desmodus Rotundus ◽

Landscape Characteristics ◽

Vampire Bat

Although the transformation of landscapes by human activity can negatively affect the populations of several bat species, other species may benefit from these transformations. One of such species is the vampire bat, Desmodus rotundus, which can often be found in landscapes dominated by livestock activities. Furthermore, there are certain structural landscape characteristics that could be positively influencing the abundance of the vampire bat. To assess this possibility, eight sampling sites in northeastern Yucatan, Mexico were monitored from June 2010 to February 2012. Four sites were located in forest fragments amongst a highly fragmented landscape dominated by pastures dedicated to livestock activities, and four sites were located within continuous tropical semideciduous forest with almost no fragmentation. Forest fragmentation was characterized around the sampling sites within a 2.5 km radius using SPOT images from 2010, and five landscape variables were calculated using FRAGSTATS. The results showed that landscape heterogeneity and an agricultural aggregation index both had a significant effect on the abundance of the vampire bat. Our results showed that D. rotundusabundance in northeastern Yucatan, Mexico was favored by extensive pastures as well as by landscape characteristics associated with intense forest fragmentation. However, the presence of some remnants of forest cover probably enhance the movements and persistence of this species. To reduce the negative impact of the vampire bat presence in these areas dedicated to livestock ranching activities, effective preventive vaccination campaigns could be an important strategy.

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Bird species that occupy river edge in continuous forest tend to be less sensitive to forest fragmentation

Revista Brasileira de Ornitologia ◽

10.1007/bf03544468 ◽

2019 ◽

Vol 27 (3) ◽

pp. 172-186

Author(s):

Barbara Rocha Arakaki Lindsey ◽

Gabriela Menezes Bochio ◽

Luiz dos Anjos

Keyword(s):

Forest Fragmentation ◽

Bird Species ◽

Forest Edge ◽

Bird Communities ◽

Forest Fragments ◽

Small Stream ◽

Edge Habitat ◽

Forest Interior ◽

Continuous Forest ◽

Significant Difference

AbstractAlong a distance gradient from a given river, two types of habitat can be recognized: natural river edge and forest interior, each one with its own vegetation characteristics and dynamics. In a continuous area of the Brazilian Atlantic Forest, we investigated (1) if bird communities are different between a riverbank of a small stream and an inland forest habitat; (2) if the species of the river edge habitat are the ones that persist in the most in forest fragments after deforestation of a continuous forest; (3) if the river edge habitat species are those that are less sensitive to forest fragmentation. It is expected that there are differences in the bird communities and the occupancy of some species between the two habitats. We allocated 16 sampling points in each of the habitats and sampled the birds by point counts with a short radius of 30 m. Results suggest that there is a significant difference between the composition of the bird communities of the river edge and forest interior habitats, although the species richness is similar. Six species were more likely to occupy the river edge and 14 species had a greater probability of occupancy in the forest interior. Species associated with the river edge habitat (15 species) tend not to be sensitive to forest fragmentation (12 species). In this study, we demonstrated that river-border species of continuous forest areas form a significant part of the bird communities that persist in small forest fragments, with intense edge effect. This shows that not all forest edge species are the result of the colonization from open areas. Congruently, species that occupy the most distant areas from the river vegetation in a continuous forest are those more sensitive to forest fragmentation.

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Avian responses to fragmentation of the Maulino Forest in central Chile

Oryx ◽

10.1017/s0030605304000742 ◽

2004 ◽

Vol 38 (4) ◽

pp. 383-388 ◽

Cited By ~ 50

Author(s):

Pablo M. Vergara ◽

Javier A. Simonetti

Keyword(s):

Forest Fragmentation ◽

Pine Plantations ◽

Native Forest ◽

Forest Fragments ◽

Forest Reserve ◽

Continuous Forest ◽

Temperate Deciduous Forests ◽

Abundance And Diversity ◽

Species Richness And Abundance ◽

Maulino Forest

Depending on the mosaic of habitats that is created, forest fragmentation can reduce the abundance and diversity of forest birds. Temperate deciduous forests in South America are rapidly being replaced by pine plantations, causing changes in habitats for both breeding and migrant birds. We examined differences in avian species richness and abundance in three areas: a reserve with continuous tracts of native forest, forest fragments and pine plantations. Four species were negatively affected by fragmentation, with their abundance declining from continuous forest to pine plantations. Fourteen species were not affected by fragmentation and eight had significantly increased abundance in pine plantations compared to continuous forest. Overall abundance in pooled and ground/understorey birds was higher in forest fragments and pine plantations compared to continuous forest. The abundance of granivorous species was higher in the pine plantations than in the forest reserve, but the abundance of insectivorous species was higher in the forest reserve and in forest fragments than in pine plantations. Thus, forest fragmentation affects birds differentially according to their feeding ecology.

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