scholarly journals Species-Area Relationships Induced by Forest Habitat Fragmentation Apply Even to Rarely Detected Organisms

2021 ◽  
Vol 14 ◽  
pp. 194008292110173
Author(s):  
Ana Filipa Palmeirim ◽  
Rafael de Fraga ◽  
Marcus V. Vieira ◽  
Carlos A. Peres
Keyword(s):  
Biodiversity Loss ◽  
Forest Fragments ◽  
Detection Rates ◽  
Conservation Policies ◽  
Number Of Species ◽  
Continuous Forest ◽  
Forest Sites ◽  
Species Area ◽  
Riparian Habitats ◽  
Forest Islands

Neotropical snakes have extremely low detection rates, hampering our understanding of their responses to habitat loss and fragmentation. We addressed this gap using a limited sample (50 individuals, 16 species) across 25 variable-size insular forest fragments within a hydroelectric lake and four adjacent mainland continuous forest sites, in Central Brazilian Amazonia. The number of species recorded on forest islands (1.55 [Formula: see text] 0.78) was much lower than that at continuous forest sites (5.0 [Formula: see text] 3.1), with no snakes being recorded at twelve islands smaller than 30 ha. As such, snake assemblages were positively affected by forest area, explaining 48% of the number of species, and negatively affected by island isolation. The markedly higher number of species recorded across continuous forest sites likely results from the availability of riparian habitats, which have virtually disappeared from the archipelagic landscape given the widespread inundation of lowland areas. To prevent further severe biodiversity loss, including those of poorly known rare taxa, conservation policies should avert the additional construction of mega-dams that create myriad of small islands, in addition to extensive reservoir lakes from which all riparian habitats are eliminated.

scholarly journals Species composition of climbers in seasonal semideciduous forest fragments of Southeastern Brazil

2009 ◽  
Vol 9 (4) ◽  
pp. 175-188 ◽  
Author(s):  
Karin dos Santos ◽  
Luiza Sumiko Kinoshita ◽  
Andréia Alves Rezende
Keyword(s):  
Floristic Composition ◽  
Southeastern Brazil ◽  
Forest Site ◽  
Forest Fragments ◽  
Semideciduous Forest ◽  
Number Of Species ◽  
Forest Sites ◽  
Forest Remnants ◽  
Mean Similarity ◽  
Made In

In this study we evaluated floristic composition patterns of communities of climbers within ten inventories carried out in semideciduous forest fragments of southeastern Brazil. One of the inventories is original, being carried out for the present study in Ribeirão Cachoeira forest, Campinas, São Paulo State, Southeastern Brazil. This inventory was then pooled together to other nine climbers' inventories made in other forests of Southeastern Brazil to form a data base, which was examined regarding species richness, similarity, species distribution and climbing methods. The total number of species obtained was 355, belonging to 145 genera and 43 families. The ten most diverse families Bignoniaceae (45 species), Fabaceae (42), Malpighiaceae (36), Asteraceae (31), Apocynaceae (29), Sapindaceae (28), Convolvulaceae (21), Cucurbitaceae (14), Passifloraceae (10), and Euphorbiaceae (8) contributed to 74.4% of the total number of species recorded. The commonest climbing method in the studied sites was main stem or branch twining, accounting for 178 species or 50.1% of the total, the second commonest was tendril climbing (121 species, 34.1%), and the least, scrambling (56 species, 15.8%). We found a high percentage of exclusive species i.e., those occurring in only one forest site, which accounted for 49.3% of the total recorded. The mean similarity among forest sites (30%) may be considered low. The climbing species contribution to the total wood plant richness recorded on the forests sites was very high in some of the sites (up to 52.5%). These results indicated the importance of climber communities to plant diversity for semideciduous forests in Southeastern Brazil, enhancing the regional diversity and the conservation value of these forest remnants.

Changes in aboveground locomotion of a scansorial opossum associated to habitat fragmentation

2020 ◽  
Vol 101 (4) ◽  
pp. 1097-1107
Author(s):  
Ana Cláudia Delciellos ◽  
Suzy Emidio Ribeiro ◽  
Jayme Augusto Prevedello ◽  
Marcus Vinícius Vieira
Keyword(s):  
Habitat Fragmentation ◽  
Animal Movement ◽  
Interspecific Interactions ◽  
Home Ranges ◽  
Forest Fragments ◽  
Active Selection ◽  
Continuous Forest ◽  
Forest Sites ◽  
Males And Females ◽  
Selection Of

Abstract Habitat fragmentation may affect animal movement patterns due to changes in intra- and interspecific interactions as well as in habitat quality and structure. Although the effects of habitat fragmentation on terrestrial movements are relatively well-known, it is unclear whether and how they affect aboveground locomotion of individuals. We compared aboveground locomotion of a Neotropical small mammal, the gray four-eyed opossum, Philander quica, between two forest fragments and two areas of continuous forest in the Brazilian Atlantic Forest. We 1) quantified support availability and tested for active selection of different support diameters and inclinations by individuals; and 2) compared support diameters and inclinations used (observed values) among areas and between males and females. Both males and females selected supports based on diameters and inclinations in forest fragments. In continuous forests sites, females selected supports based on diameters and inclinations, but males selected only support diameters. Frequency of support diameter use differed significantly between forest fragments and continuous forest sites and between males and females. Frequency of support inclination use differed significantly between areas only for females, and between sexes only in continuous forest sites. Sex-related differences in support selection and use are likely related to differences in body size and conflicting energetic and behavioral demands related to use of arboreal space. Site-related differences in aboveground movements likely reflect the effects of forest edges that result in increased use of thinner supports in forest fragments. These results complement our previous findings that habitat fragmentation reduces daily home ranges and increases the total amount of aboveground locomotion of P. quica, and provide a more thorough picture of how forest-dependent species are able to use and persist in small forest fragments.

scholarly journals Diet and prey availability of terrestrial insectivorous birds prone to extinction in amazonian forest fragments

2010 ◽  
Vol 53 (6) ◽  
pp. 1371-1381 ◽  
Author(s):  
Luiz Augusto Macedo Mestre ◽  
Mario Cohn-Haft ◽  
Manoel Martins Dias
Keyword(s):  
Prey Size ◽  
Prey Availability ◽  
Bird Species ◽  
Sympatric Species ◽  
Territory Size ◽  
Forest Fragments ◽  
Insectivorous Birds ◽  
Continuous Forest ◽  
Forest Sites ◽  
Diet Variability

This study compared niche breath, prey size, and diet variability in two pairs of sympatric species of terrestrial insectivorous birds, each pair containing one species that can persist in small forest fragments and one that does not. The pairs were Myrmeciza ferruginea and Sclerurus rufigularis; and Formicarius colma and F. analis, respectively. The prey availability in forest fragments was also sampled and compared to the availability in continuous forests. Niche breath indices did not differ between pair members, but diet variability differed in the opposite direction from that hypothesized. Although the two bird species most vulnerable to fragmentation fed on larger prey than less vulnerable species, prey availability, including that based on prey size did not differ among fragmented versus continuous forest sites. Thus, diet per se appeared not to be an important cause of extinction-proneness in these species. The simplest explanation proposed, that vulnerability to fragmentation was directly related to territory size, requires testing. However, it was consistent with observations that the bird species feeding on larger prey also need larger territories.

scholarly journals The persistence of ant-following birds in small amazonian forest fragments

1989 ◽  
Vol 19 (0) ◽  
pp. 249-263 ◽  
Author(s):  
Lee H. Harper
Keyword(s):  
Forest Fragments ◽  
Ant Colonies ◽  
Amazonian Forest ◽  
Army Ant ◽  
Continuous Forest ◽  
Introduced Birds ◽  
Small Forest

SUMMARYMist-net captures of army ant-following bird were monitored during the isolation of central Amazonian forest fragments of 1 ha (n = 5), 10 ha (n = 4) and 100 ha (n = 1). Post-isolation captures of the three obligate ant-following birds Dendrocinela merula, Pithys albifrons, and Gymnopithys rufigula decreased significantly in all fragments. post-isolation captures of four facultative ant-following species were not significantly different in forest fragments of 1 ha and 10 ha, although two species decreased significantly in the 100 ha fragment. Experimental introductions of obligate species into small forest fragments in the absence and presence of introduced Eciton burchelli army ant colonies resulted in significantly greater recaptures of introduced birds when active army ant colonies were present. Of the 105 birds introduced, 58 ' 55%) crossed 100-320 m od dedorested area an were recaptured in continuous forest.

scholarly journals Distribution of Atta (Hymenoptera - Formicidae) in "terra-firme" rain forest of Central Amazonia: density, species composition and preliminary results on effects of forest fragmentation

1988 ◽  
Vol 18 (3-4) ◽  
pp. 309-315 ◽  
Author(s):  
Heraldo Luís de Vasconcelos
Keyword(s):  
Species Composition ◽  
Rain Forest ◽  
Abundant Species ◽  
Forest Fragments ◽  
Forest Fragment ◽  
Terra Firme ◽  
Atta Sexdens ◽  
Conservation Areas ◽  
Continuous Forest ◽  
Leaf Cutting

One hundred and fourteen hectares of a "terra-fiirme" rain forest 70 km north of Manaus, Amazonas, Brazil, were surveyed for leaf-cutting ant colonies (Atta spp). One half of this area was in isolated forest fragments (surrounded by pastures or second growth) of two sizes: 1 and 10 ha. The other half was in non-isolated fragments (connected to a large parch of forest) of the same sizes. Only two species occured in this forest: Atta sexdens sexdens L. and A. cepfhalotes L. The first was the most abundant species with a mean density of 0.35 colonies per ha. The mean density of A. cephalotes colonies was 0.03 per ha. The density of colonies was not significantly different between the isolated fragments and the continuous forest. Furthermore, the species composition did not change with isolation. However, pre-isolation data and long term monitoring are necessary to conclude that the isolation of a forest fragment has no effect upon Atta colonies. The non-uniform spatial distribution of Atta colonics within the "terra-firme" forest must be taken into account when selecting conservation areas in the Amazon, in order to preserve this important group of ants together with their native habitat.

scholarly journals Recover and They’ll Come: Flower Visiting Bees Benefit from the Continuous of Micro-Environments Set by Regenerating Forest Fragments

Sociobiology ◽  
2021 ◽  
Vol 68 (1) ◽  
pp. 5861
Author(s):  
Ana Isabel Sobreiro ◽  
Lucas Lopes da Silveira Peres ◽  
Jessica Amaral Henrique ◽  
Rosilda Mara Mussury ◽  
Valter Vieira Alves-Junior
Keyword(s):  
Urban Areas ◽  
Environmental Changes ◽  
Climatic Conditions ◽  
Agricultural Activity ◽  
Forest Fragments ◽  
Forest Types ◽  
Continuous Forest ◽  
Flower Visiting ◽  
Bee Communities ◽  
Forest Habitats

Forest habitats are important sources of food and nesting resources for pollinators, primarily in urban areas and landscapes with intense agricultural activity. The forest fragmentation and environmental changes occurring in these green refuges are known to impose survival challenges to pollinating bees, leading to species loss. However, it is not well known how the species of bees that visit flowers are distributed in forest micro-environments. To fill this gap, we sampled flower visiting bees in a continuous forest matrix with micro-environments of two forest types (mature and regenerating forest). We examined how the local environmental changes and climatic conditions affect the composition and uniformity of bee communities in the different micro-environments. Our results indicated that both abundance and richness were similar between forest types studied here, however climatic conditions and plant flowering patterns affect the composition of bees. Thus, our results demonstrated that the continuous micro-environments can favor floral visits and the reintegration of bee communities, and still, that this strategy can be used to minimize the impacts of environmental changes at local scales.

scholarly journals Primate populations in continuous forest and forest fragments in Central Amazonia

1988 ◽  
Vol 18 (3-4) ◽  
pp. 291-307 ◽  
Author(s):  
Anthony B. Rylands ◽  
Alexine Keuroghlian
Keyword(s):  
Food Sources ◽  
Primate Species ◽  
Forest Fragments ◽  
The Past ◽  
Pithecia Pithecia ◽  
Ateles Paniscus ◽  
Continuous Forest ◽  
Second Growth ◽  
Central Amazonia ◽  
One Year

Population densities of six primate species (Saguinus midas, Pithecia pithecia, Cebus apella, Chiropotes satanas, Alouatta seniculus and Ateles paniscus) were estimated in continuous forest and in isolated reserves (one of 100 ha and four of 10 ha). Saguinusdensities in the continuous forest were found to be low, probably due to the lack of edge habitat and second growth favoured by them; Pithecia, Cebus and Ateles populations are also low, possibly because of more widely distributed and/or less abundant food sources than is true for other Amazonian regions, although hunting in the past, particularly of Ateles may also be a contributing factor; and Chiropotes and Alouatta densities were found to be similar to those observed in other areas of Amazonas forests. Ateles and Chiropotes, which occupy ranges on the order of three km2 were excluded from the 100-ka reserve at the time of its isolation. Unfortunately populations were not known prior to isolation of this reserve but during isolation there remained four groups of Saguinus, two Pitheciagroups, one Cebus groups and five Alouatta groups. One Saguinus group disappeared two months later, and one year post-isolation the Cebus group also left the reserve. Single Alouatta groups survive in the isolated 10-ha reserves. Saguinus, present in the four 10-ha reserves following isolation, have disappeared from two of them. One 10-ha reserve retains a group of Pithecia.

Seed Banks in Savanna, Forest Fragments, and Continuous Forest Edges Differ in a Tropical Dry Forest in Madagascar

Biotropica ◽  
2015 ◽  
Vol 47 (4) ◽  
pp. 435-440 ◽  
Author(s):  
Kim Valenta ◽  
Travis S. Steffens ◽  
Radoniaina R. Rafaliarison ◽  
Colin A. Chapman ◽  
Shawn M. Lehman
Keyword(s):  
Tropical Dry Forest ◽  
Seed Banks ◽  
Dry Forest ◽  
Forest Fragments ◽  
Forest Edges ◽  
Continuous Forest

Organisation de la richesse et de la composition floristiques d'îles de la Méditerranée occidentale (sud-est de la France)

1998 ◽  
Vol 76 (2) ◽  
pp. 321-331 ◽  
Author(s):  
Frédéric Médail ◽  
Éric Vidal
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Plant Species ◽  
Habitat Diversity ◽  
Mediterranean Islands ◽  
Plant Dispersal ◽  
Number Of Species ◽  
Continental Islands ◽  
Species Area ◽  
Species Area Relationship

The effects of physiographic variables (area, isolation, elevation, and substrate) and habitat diversity on plant species richness and composition have been investigated on some Mediterranean islands (southeastern France). The number of species - area relationship is significant but there are more diverse vegetation patterns on smallest islands (area smaller than 3.5 ha and, ultimately, 0.2 ha). Although the species composition is positively correlated to the distance from the continent, the effect of isolation is not so obvious because of the small distance of these continental islands from the continent. Some islands nearest to shore show very different plant species composition, suggesting a nonselective plant dispersal through some narrow stretches of sea. Habitat diversity represents one of the major explanatory factors of the species richness; nevertheless, it is not possible to settle between the two hypotheses effect of habitat diversity versus effect of area per se because of the correlation between the two factors. Key words: Mediterranean islands, insular biogeography, number of species - area relationship, isolation, habitat diversity, islets.

Effect of forest patch area on population attributes of white-footed mice (Peromyscus leucopus) in fragmented landscapes

1996 ◽  
Vol 74 (3) ◽  
pp. 467-472 ◽  
Author(s):  
Thomas E. Nupp ◽  
Robert K. Swihart
Keyword(s):  
Adult Male ◽  
Peromyscus Leucopus ◽  
Reproductive Activity ◽  
Forest Area ◽  
Male Mice ◽  
Patch Area ◽  
Forest Patch ◽  
Fragmented Landscapes ◽  
Continuous Forest ◽  
Forest Sites

We studied population densities, sex ratios, adult masses, reproductive activity, age structure, and over-summer recapture rates of white-footed mice (Peromyscus leucopus) in 15 woodlots of various sizes and three continuous-forest sites to ascertain the effects of forest patch area on these population attributes. Our study was conducted in west-central Indiana during spring 1992 and 1993 and autumn 1992. Densities of white-footed mice were inversely related to forested area. A survey of previous studies conducted at similar latitudes revealed a similar pattern. Extremely high densities (up to 200 adults/ha) were found in small woodlots (< 0.5 ha). Mass of adult male mice also was inversely related to forest area, and a positive relationship between proportion of adult male mice and forest area was suggested. Ratios of juveniles to adults were positively related to forest area in autumn but not in spring. The proportion of sexually active individuals in the population was not related to forest area, nor were over-summer recapture rates. Our findings indicate that patch area can have dramatic effects on the structure and dynamics of populations of white-footed mice inhabiting fragmented landscapes.

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