Effects of Amazonian forest fragmentation on the interaction between plants, insect herbivores, and their natural enemies

2008 ◽  
Vol 24 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Sarita B. Fáveri ◽  
Heraldo L. Vasconcelos ◽  
Rodolfo Dirzo
Keyword(s):  
Forest Fragmentation ◽  
Forest Area ◽  
Insect Herbivores ◽  
Forest Fragment ◽  
Linear Effect ◽  
Structure And Dynamics ◽  
Continuous Forest ◽  
Species Specific ◽  
Amazonian Trees ◽  
Small Forest

Abstract:We evaluated the effects of forest fragmentation on herbivory on central Amazonian trees. Levels of herbivory were measured on leaves from a total of 1200 saplings from 337 species. There was a positive and significant effect of forest fragment area on herbivore damage, with plants from continuous forest having twice as much damage as plants in the smallest fragments studied (1 ha). Measurements of herbivory rates on two species, however, indicate that the effect can be species-specific. Forest area had a positive and linear effect on rates of herbivory in Henriettella caudata (Melastomataceae), whereas in Protium hebetatum (Burseraceae), rates of herbivory were greater in the 10-ha fragments than in the 1-ha fragments and in continuous forest. There is no evidence that the nutritional and defensive characteristics of the leaves of the species we studied changed as a result of forest fragmentation, at least not in a manner consistent with the observed herbivory patterns. Herbivore predation levels, measured with artificial caterpillars, also showed no significant relationship with forest area. Therefore, neither of these top-down and bottom-up forces could explain the observed patterns of herbivory. It is suggested, instead, that forest fragmentation may affect the dispersal of insect herbivores, and reduce their abundances on small forest isolates. Altered patterns of herbivory on tree saplings may have important consequences for forest structure and dynamics.

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 National mapping and estimation of forest area by dominant tree species using Sentinel-2 data

2020 ◽  
Author(s):  
Johannes Breidenbach ◽  
Lars T. Waser ◽  
Misganu Debella-Gilo ◽  
Johannes Schumacher ◽  
Johannes Rahlf ◽  
...  
Keyword(s):  
Tree Species ◽  
Deciduous Forest ◽  
National Level ◽  
National Forest Inventory ◽  
Forest Area ◽  
Forest Resource ◽  
Species Specific ◽  
Minimum Numbers ◽  
Generate Model ◽  
Sentinel 2

Nation-wide Sentinel-2 mosaics were used with National Forest Inventory (NFI) plot data for modelling and subsequent mapping of spruce-, pine- and deciduous-dominated forest in Norway at a 16m×16m resolution. The accuracies of the best model ranged between 74% for spruce and 87% for deciduous forest. An overall accuracy of 90% was found on stand level using independent data from more than 42,000 stands. Errors mostly resulting from a forest mask reduced the model accuracies by approximately 10%. The produced map was subsequently used to generate model-assisted (MA) and post stratified (PS) estimates of species-specific forest area. At the national level, efficiencies of the estimates increased by 20% to 50% for MA and up to 90% for PS. Greater minimum numbers of observations constrained the use of PS. For MA estimates of municipalities, efficiencies improved by up to a factor of 8 but were sometimes also less than 1. PS estimates were always equally as or more precise than direct and MA estimates but were applicable in fewer municipalities. The tree species prediction map is part of the Norwegian forest resource map and is used, among others, to improve maps of other variables of interest such as timber volume and biomass.

scholarly journals Going extinct before being discovered? New lichen fungi from a small fragment of the vanishing Atlantic Rainforest in Brazil

2018 ◽  
Vol 18 (1) ◽  
Author(s):  
Thamires Almeida Pereira ◽  
Paula de Oliveira Passos ◽  
Lidiane Alves dos Santos ◽  
Robert Lücking ◽  
Marcela Eugenia Da Silva Cáceres
Keyword(s):  
New Species ◽  
Rare Species ◽  
Atlantic Rainforest ◽  
Northeast Brazil ◽  
Small Fragment ◽  
Forest Fragment ◽  
Deforestation Rate ◽  
The Past ◽  
Small Forest

Abstract In the frame of an ongoing lichen inventory of Atlantic Rainforest remnants in Northeast Brazil, five new species of Graphidaceae were discovered in a small forest fragment, Mata do Cipó, in Sergipe state, the smallest state of Brazil and among those with the highest deforestation rate in the country. An additional new species had already been collected in Panama before and was now also found in the Mata do Cipó and is described here as well. In total, 40 species of Graphidaceae are reported for this remnant, including a large number of taxa indicative of well-preserved rainforest. The new species are: Fissurina atlantica T.A. Pereira, M. Cáceres & Lücking, sp. nov., Graphis subaltamirensis Passos, M. Cáceres & Lücking, sp. nov., Ocellularia cipoensis L.A. Santos, M. Cáceres & Lücking, sp. nov., O. sosma T.A. Pereira, M. Cáceres & Lücking, sp. nov., O. submordenii Lücking, sp. nov. (also known from Panama), and Pseudochapsa aptrootiana M. Cáceres, T.A. Pereira & Lücking, sp. nov. The findings are discussed in the context of the strong fragmentation of the Atlantic Rainforest, with individual remnants apparently serving as refugia for residual populations of rare species of lichen fungi that were more widely distributed in the past, but currently seem to occur only in isolated fragments.

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.

scholarly journals Phytosociology of the shrub-arboreal stratum of the Ibura National Forest, Northeastern Brazil: are 35 years sufficient to promote the regeneration of a forest fragment?

2020 ◽  
Vol 15 (2) ◽  
pp. 89-106
Author(s):  
José Paulo Santana ◽  
Patrício Adriano da Rocha ◽  
Eduardo Vinícius da Silva Oliveira ◽  
Ana Paula Nascimento Prata ◽  
Adauto Souza Ribeiro
Keyword(s):  
Basal Area ◽  
Forest Area ◽  
Northeastern Brazil ◽  
National Forest ◽  
Native Forest ◽  
Average Height ◽  
Forest Fragment ◽  
Successional Stage ◽  
Significant Difference ◽  
Corymbia Citriodora

Among the various applications of phytosociology, the evaluation of natural regeneration is of great importance, mainly because it provides insights for ecological restoration. The objective of this study was to analyze the composition and phytosociological parameters of shrub and tree vegetation in areas of plantation of eucalyptus (Corymbia citriodora) and areas of native forest in the Ibura National Forest, located in the Sergipe state of northeastern Brazil. For this purpose, 20 plots were sampled and all individuals with a diameter at breast height (DBH) ≥ 8 cm were measured. Sampling revealed 821 individuals in the forest area and 1,000 in the eucalyptus area. These individuals represent 84 species and the areas presented a significant difference in species composition, with 61 in the eucalyptus area and 65 in the Forest area, and only 40 species were common to both areas. There was a predominance of pioneer individuals in the eucalyptus area. There also was a significant difference in basal area, relative density and relative dominance, but no significant differences were observed in average height. It was concluded that a period of 35 years is insufficient for the recovery of the eucalyptus area, which remains in a more initial successional stage than the forest area.

Anthurium narae—A new species of Araceae from a small forest fragment in southeastern Brazil

Phytotaxa ◽  
2018 ◽  
Vol 351 (1) ◽  
pp. 81
Author(s):  
MEL C. CAMELO ◽  
MARCUS A. N. COELHO ◽  
LÍVIA G. TEMPONI
Keyword(s):  
New Species ◽  
Geographical Distribution ◽  
Conservation Status ◽  
Montane Forest ◽  
Southeastern Brazil ◽  
Similar Species ◽  
Brazilian Atlantic Forest ◽  
Forest Fragment ◽  
A New Species ◽  
Small Forest

Anthurium narae is described from the state of Minas Gerais, in southeastern Brazil. It occurs in a small forest fragment of semideciduous seasonal montane forest, a component of Brazilian Atlantic Forest. Descriptions, illustrations, photographs and comparison with other similar species of Anthurium sect. Urospadix are provided together with comments about geographical distribution, ecology, phenology, and conservation status.

scholarly journals Characterization of Exopolysaccharides Produced by Rhizobia Species

2015 ◽  
Vol 39 (6) ◽  
pp. 1566-1575 ◽  
Author(s):  
Tereza Cristina Luque Castellane ◽  
Alda Maria Machado Bueno Otoboni ◽  
Eliana Gertrudes de Macedo Lemos
Keyword(s):  
High Performance ◽  
Biological Properties ◽  
Reversed Phase ◽  
The Past ◽  
Structure And Dynamics ◽  
Key Factor ◽  
Reactive Groups ◽  
Potential Applications ◽  
Species Specific

ABSTRACT Increasing attention has been given, over the past decades, to the production of exopolysaccharides (EPS) from rhizobia, due to their various biotechnological applications. Overall characterization of biopolymers involves evaluation of their chemical, physical, and biological properties; this evaluation is a key factor in understanding their behavior in different environments, which enables researchers to foresee their potential applications. Our focus was to study the EPS produced by Mesorhizobium huakuii LMG14107, M. loti LMG6125, M. plurifarium LMG11892,Rhizobium giardini bv. giardiniH152T, R. mongolense LMG19141, andSinorhizobium (= Ensifer)kostiense LMG19227 in a RDM medium with glycerol as a carbon source. These biopolymers were isolated and characterized by reversed-phase high-performance liquid chromatography (RP-HPLC), Fourier transform infrared (FTIR), and nuclear magnetic resonance (NMR) spectroscopies. Maximum exopolysaccharide production was 3.10, 2.72, and 2.50 g L-1for the strains LMG6125, LMG19227, and LMG19141, respectively. The purified EPS revealed prominent functional reactive groups, such as hydroxyl and carboxylic, which correspond to a typical heteropolysaccharide. The EPS are composed primarily of galactose and glucose. Minor components found were rhamnose, glucuronic acid, and galacturonic acid. Indeed, from the results of techniques applied in this study, it can be noted that the EPS are species-specific heteropolysaccharide polymers composed of common sugars that are substituted by non-carbohydrate moieties. In addition, analysis of these results indicates that rhizobial EPS can be classified into five groups based on ester type, as determined from the 13C NMR spectra. Knowledge of the EPS composition now facilitates further investigations relating polysaccharide structure and dynamics to rheological properties.

Anthurium narae—A new species of Araceae from a small forest fragment in southeastern Brazil

Phytotaxa ◽  
2018 ◽  
Vol 351 (1) ◽  
pp. 81
Author(s):  
MEL C. CAMELO ◽  
MARCUS A. N. COELHO ◽  
LÍVIA G. TEMPONI
Keyword(s):  
New Species ◽  
Geographical Distribution ◽  
Conservation Status ◽  
Montane Forest ◽  
Southeastern Brazil ◽  
Similar Species ◽  
Brazilian Atlantic Forest ◽  
Forest Fragment ◽  
A New Species ◽  
Small Forest

Anthurium narae is described from the state of Minas Gerais, in southeastern Brazil. It occurs in a small forest fragment of semideciduous seasonal montane forest, a component of Brazilian Atlantic Forest. Descriptions, illustrations, photographs and comparison with other similar species of Anthurium sect. Urospadix are provided together with comments about geographical distribution, ecology, phenology, and conservation status.

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