Secondary Atlantic Rainforest Research Articles

Canopy recovery four years after logging: a management study in a southern brazilian secondary forest

ABSTRACT Background: Understanding forest dynamics after logging is essential to define forest management cycles and intensities. In secondary forest, especially in the Atlantic Forest Domain, these studies are still scarce. Monitoring of the canopy structure after tree harvesting can be performed by hemispherical photographs, where canopy opening is commonly analyzed. This study evaluated changes in canopy opening four years after tree harvesting in a secondary Atlantic Rainforest in southern Brazil. We used hemispherical photographs to determine the Canopy Openness (CO), Leaf Area Index (LAI), and Diffuse Fraction of Photosynthetically Active Absorbed Radiation (FAPARdif) in eleven permanent plots. Results: We found that harvesting resulted in a momentary increase in canopy opening and light availability in the understory. Four years after harvesting, CO, LAI and FAPARdif recovered or even exceeded the original values of the forest. We observed a significant correlation between CO and number of trees harvested with DBH > 30 cm. Weak correlations were found between these canopy related variables and the logging intensity. Conclusion: In conclusion, we recognized that changes of CO, LAI and FAPARdif after timber harvesting presented short duration. This indicates that the applied logging intensities, 21.8 to 51.1% of the total basal area, did not exceed the resilience of the forest canopy and it’s recovering four years later. However, additional studies should be carried out to observe vegetation dynamics, such as species composition, vertical structure, productivity and community stability, in order to improve management schemes of secondary stands in the Atlantic Forest.

Canopy Architecture After Selective Logging in a Secondary Atlantic Rainforest in Brazil

ABSTRACT Sustainable forest management promotes financial revenues while keeping the forest cover and environmental services. Nevertheless, the logging operation causes changes in the forest and canopy horizontal and vertical structure. Our objective is to evaluate the changes in the forest canopy and its consequences to the forest management, following logging in a secondary Atlantic Rainforest. We used hemispherical photography to determine the Canopy Openness (CO), Leaf Area Index (LAI) and the radiation absorption (fAPAR) in nine experimental plots before and after logging. We did not find a clear correlation between the forest horizontal structure and the canopy architecture. Despite this, there was an increase in CO and decrease in LAI and fAPAR after logging. The variation in CO and fAPAR were affected by logging intensity, but LAI did not show the same pattern. We suggest a conservative maximum logging intensity of 30% of the basal area and tree density.

Amphibia, Anura, Hylidae, Bokermannohyla lucianae (Napoli and Pimenta, 2003): distribution extension and geographic distribution map

The geographic distribution of Bokermannohyla lucianae, know only from its type locality in the municipality of Una, is extended 60 km south and 60 km south-west with two new localities in southern Bahia. The species seems to be restricted to remnants of primary and secondary Atlantic Rainforest patches in a small area of southern Bahia.

Mineral nutrient fluxes in rainfall and throughfall in a lowland Atlantic rainforest in southern Brazil

The ecosystems occurring on dystrophic soils, such as sandy soils, are highly dependent on nutrients from the atmosphere and those cycled by their own biota. Nutrient inputs from rainfall and throughfall were measured between October 2001 and August 2003 in a secondary Atlantic rainforest in southern Brazil. Canopy interception (rainfall minus throughfall) was 17.3% of the annual rainfall of 2,235 mm. Monthly interception ranged from 12 to 31% during the rainiest months (precipitation above 200 mm) and from 1 to 45% during the driest months (precipitation below 50 mm) indicating relatively high variability during this period. The studied site may be susceptible to water stress in this period due to the high permeability of the sandy soil. Approximately 80% of the Ca and Na and 57% of Mg were mainly from rainfall (bulk deposition) whereas the main input source for K was net throughfall (about 78%). Mean annual inputs via throughfall (in kg ha−1) were: 90.6 for Na, 29.1 for K, 7.1 for Ca, and 2.9 for Mg. The highest nutrient inputs occurred during the rainy season. Na fluxes were relatively high, while K, Ca, and Mg inputs were low, compared with other tropical and subtropical forests. Information on nutrient fluxes for different forest ecosystems are fundamental for building up a database that can give support to environmental diagnosis, to forest management, and to conservation and restoration techniques.

Jaguarundi (Puma yagouaroundi) (Geoffroy, 1803) (Carnivora, Felidae) food habits in a mosaic of Atlantic Rainforest and eucalypt plantations of southeastern Brazil

Food habits of jaguarundi (Puma yagouaroundi) (Geoffroy, 1803) (Carnivora, Felidae) were studied between November 2000 and November 2001, in a 24.9 km(2) area of secondary Atlantic Rainforest and eucalypt plantation, in the Serra de Paranapiacaba, São Paulo State, Brazil. Analyses of 26 fecal and regurgitate samples, obtained over a stretch of 570.1 km, showed the consumption of 19 prey items and 74 prey occurrences. Small mammals were the most frequent food item (42.5%), followed by birds (21%), reptiles (14%) and medium-sized mammals (3%). The percent occurrence (PO) suggests that the diet consisted mainly of small rodents (30%) and birds (21%). We recorded for the first time the predation of Viperidae snakes by P. yagouaroundi. Although having a large list of items and range of dietary niche breadths (Bsta = 0.76), our data show that jaguarundi prey mainly on small vertebrates (mammals, birds or reptiles), and even in tall tropical forests or eucalypt plantations, it preys mostly on animals that come to, or live on, the ground.

Fragmentation effects on population density of three rodent species in secondary Atlantic Rainforest, Brazil

We investigated the population density of the two common rodent species Akodon montensis, Oligoryzomys nigripes, and the more specialized endemic Delomys sublineatus in secondary forest fragments of the highly endangered coastal Atlantic Rainforest. Linear regression was used to examine relationships between population density and four landscape variables. We tested the hypothesis that rare species, which are more affected by fragmentation than the common species, should decrease in population density with decreasing fragment size while the density of common generalist species should be unaffected or increase in smaller fragments. The results revealed that A. montensis and O. nigripes showed no significant association to any landscape variable. The density of D. sublineatus showed a strong tendency to a positive correlation to fragment size as well as a negative correlation to edge density. The results underline the importance of large and connected forest remnants in the Atlantic Rainforest to guarantee an effective protection of endemic small mammal species.

Interaction network and the relationships between bromeliads and hummingbirds in an area of secondary Atlantic rain forest in southern Brazil

The reciprocal importance of bromeliads and hummingbirds has been proposed for many years, even suggesting coevolution between these two groups. Nevertheless, data are lacking that allow a better test of the relationships involved. Here we investigate the relationship between bromeliads and hummingbirds in an area of secondary Atlantic rain forest in southern Brazil. The study examined the interactions among 12 species of bromeliad and 10 of hummingbird at Reserva Natural Salto Morato, Paraná state. The number of flowering species of bromeliad and the species richness and abundance of hummingbirds were quantified monthly between November 2004 and October 2005. Focal observations on each bromeliad species were made to determine the hummingbird visitors. Neither species richness nor abundance of hummingbirds were related to bromeliad phenology. Together with the monthly variation in visit frequency by a given pollinator to a given plant, these factors indicate a generalization in the use of bromeliads by hummingbirds and argue against tight coevolution. Ramphodon naevius and Thalurania glaucopis were the main pollinators in the community. Aechmea nudicaulis was the most generalist bromeliad species. The generalist species interacted with other generalists or with asymmetric specialists and there was no specialist–specialist interaction. This produced a strongly organized and nested matrix of interactions. This nestedness is similar to other plant-pollinators networks, supporting the hypothesis that the evolutionary relationship between bromeliads and hummingbirds is no stronger than that of other pollination networks.

Bromeliad-associated mosquitoes from Atlantic forest in Santa Catarina Island, southern Brazil (Diptera, Culicidae), with new records for the State of Santa Catarina

Bromeliad-associated mosquitoes (Diptera: Culicidae) in Atlantic Forest in Florianópolis, Santa Catarina, southern Brazil, were studied, examining plants of Vriesea philippocoburgi Wawra and Aechmea lindenii (E. Morren) Baker var. lindenii at secondary Atlantic rain forest, and A. lindenii and Vriesea friburgensis Mez var. paludosa (L. B. Smith) at "restinga" per month, during 12 months. No immature forms of mosquitoes were collected from A. lindenii in the secondary forest. Collections obtained 368 immature mosquitoes, none of them from A. lindenii from rain forest. Culex (Microculex) spp. constituted 79.8% of the total, Wyeomyia (Phoniomyia) spp. 17.93%, and Anopheles (Kerteszia) cruzii (Dyar & Knab, 1908) only 1.36%. The study shows the great predominance of species of medical importance not yet proved, and the small number of immature stages of anopheline mosquitoes. The rainfall, but not the mean temperatures, significantly influenced the quantity of mosquitoes from V. philippocoburgi. Significant differences between the quantities of immature forms of all the bromeliad species were found, and the shape of the plants could be important to the abundance of mosquitoes. All six species of Cx. (Microculex) found are recorded for the first time in the State of Santa Catarina, and all six species of Wyeomyia (Phoniomyia) are recorded for the first time in bromeliads in this state.

Composição de gastrópodes terrestres em duas áreas do Centro de Estudos Ambientais e Desenvolvimento Sustentado (CEADS), Vila Dois Rios, Ilha Grande, Rio de Janeiro, Brasil: um estudo-piloto

A survey of the Ilha Grande land snails was carried out in order to compare the diversity and similarity among two regions of secondary Atlantic Rain Forest. The diversity was estimated using the richness and the equitatibility; the alpha diversity was calculated using the Simpson index (γ). The Sorensen and Jaccard indexes were used to calculate the similarity. A quantitative survey of two 600 m2 area, one in each studied region, recorded 336 individuals snails distributed in 23 species and 13 families. The region with more altered secondary forest showed higher richness (17) and diversity (γ = 3,6) than the region more preserved (richness = 14; γ = 2,78), but, the same equitatibility (0,20). The similarity was medium by Jaccard index (IJ = 0,52) and low by Sorensen index (IS = 0,15). These differences could be explained by the dominance of Subulinidae (four species and 117 specimens) in the more altered region and Systrophiidae in the more preserved (four species and 97 specimens).

Response of stress indicators and growth parameters of Tibouchina pulchra Cogn. exposed to air and soil pollution near the industrial complex of Cubatão, Brazil

The present study was performed in the vicinity of the industrial complex of Cubatão, São Paulo, Brazil, in order to evaluate the response of ‘manaca da serra’ Tibouchina pulchra Cogn. (Melastomataceae), a common species of secondary Atlantic Rain Forest vegetation, to the impact of complex air pollution. Emphasis was given to changes of biochemical parameters such as ascorbic acid concentration, peroxidase activity, contents of water-soluble thiols, pH of leaf extract and buffering capacity. These plant factors are often used as early indicators of air pollution stress. Field experiments included sampling of leaves from mature trees in areas with different air pollution load (passive monitoring), exposure of saplings cultivated in uniform soil at these areas (active monitoring) and a study on the combined effects of contaminated soil and air pollution. In general, metabolic response of saplings was more accentuated than that of mature trees. Leaf extract pH and buffering capacity showed no or only small alterations in plants exposed to industrial emissions. In contrast, air pollution resulted in a distinct decrease in ascorbic acid contents and an increase in peroxidase activity and thiol concentrations in leaves. Cultivation of saplings in soil types from contaminated regions frequently caused the same modifications or enhanced the effects produced by air pollution. Growth analysis of exposed saplings demonstrated that a change of the relationship between above-ground and below-ground plant parts was the most obvious effect of air pollution and soil contamination. The experiments showed that even T. pulchra, a species considered resistant to air pollution, suffers metabolic disturbances by the present ambient air and soil quality. Although biochemical and physiological alterations were not related to a certain air pollution type, they could be used to estimate the overall pollution load and to map zones with different air quality.

Conservation status of parrot populations in an Atlantic rainforest area of southeastern Brazil

A census of four species of syntopic parrots was carried out using distance sampling methods on Sao Sebastiao island, SE Brazil. Most of the 33 593 ha island is covered by mature and secondary Atlantic rainforest. Almost 80% of these forests are within the Ilhabela Park. Although the species counted have marked differences in size and weight, density (individuals/km2) and estimated population size in 23 500 ha of well-preserved forests were similar: Amazona farinosa (13.82 ± 5.94; 3247 ± 1395), Pionus maximiliani (15.79 ± 7.04; 3712 ± 1654), Brotogeris tirica (15.05 ± 4.87; 3537 ± 1143) and Pyrrhura frontalis (13.06 ± 5.53; 3068 ± 1298). Encounter rates of Forpus crassirostris and Pionopsitta pileata were very low, which suggests that there is only a small population of these species on the island. The Sao Sebastiao forests still support healthy populations of parrots. Although woodpecker population estimates on the island are large enough to provide nesting sites for parrots, competition for holes with other secondary cavity nesters such as toucans, flycatchers and tytiras, and the selective cutting of dead trees for canoe construction, which is a common practice on the island, may limit hole availability for parrots.

Observações preliminares sobre a frugivoria por aves em Alchornea glandulosa (Endl. & Poepp.) (Euphorbiaceae) em vegetação secundária

An individual of Alchornea glandulos a (Endl. & Poepp.) was observed in Blumenau (26o55'26, S49o03'22W), Santa Catarina State on the border of secondary Atlantic Rain Forest from september to november belween 1990 and 1991, with the goal of identifying species of birds with potential to spread out its seeds. In twelve hours of observation 21 species of birds explorcd the seeds.