Old growth mature forest types and their floristic composition along the altitudinal gradient on Silhouette Island (Seychelles) – the telescoping effect on a continental mid-oceanic island

2009 ◽  
Vol 39 (2) ◽  
pp. 157-174 ◽  
Author(s):  
Bruno Senterre ◽  
Justin Gerlach ◽  
James Mougal ◽  
Denis Matatiken
2016 ◽  
Vol 106 (0) ◽  
Author(s):  
Rodrigo M. Mello ◽  
Pedro H. Nobre ◽  
Marco A. Manhães ◽  
Alexmar S. Rodrigues

ABSTRACT Many studies have demonstrated the ecological relevance and great biodiversity of bats in Brazil. However, mountainous areas have been disproportionately less sampled, mainly in the Southeast. The aim of this study was to identify and compare the richness and diversity of Phyllostomidae, the most diverse bat family, in different forest types in Parque Estadual do Ibitipoca, trying to understand the causes of possible differences. The Parque Estadual do Ibitipoca is inserted in the Serra da Mantiqueira's domain, in an Atlantic Forest region known as "Zona da Mata", state of Minas Gerais, with an altitudinal range between 1200-1784 meters. The study was conducted in two forest types, classified as "Nanofloresta Nebular" and "Floresta Nebular", whose respective data on richness and diversity were compared. The bats were captured with 8-10 mist nets for 14 months (April 2011 to May 2012) and four nights per month totaling 62,171.25 m2h of capture effort. A total of 392 captures (12 species) belonging to the Phyllostomidae family were obtained. The most abundant species were Sturnira lilium (59.9%), Platyrrhinus lineatus (11.3%), Artibeus lituratus (8.7%) and Carollia perspicillata (7.6%). The two sampled areas presented differences in bat richness, diversity and species composition, and this difference was predominantly influenced by S. lilium. It is likely that the observed difference in the assembly of bats between the two study sites depends on the variation in floristic composition. The records of A. lituratus and P. lineatus in a few months of the year and close to Ficus mexiae bearing ripe fruits suggests that at least these species move to the park for a few periods of the year in search of food resources, possibly moving through the altitudinal landscapes.


2004 ◽  
Vol 82 (10) ◽  
pp. 1518-1538 ◽  
Author(s):  
Christine Roberts ◽  
Oluna Ceska ◽  
Paul Kroeger ◽  
Bryce Kendrick

Over 5 years, macrofungi from six habitats in Clayoquot Sound, Vancouver Island, British Columbia, were documented. Habitats were categorized as dune, spruce fringe, old-growth rainforest, second-growth forest, bog, or estuarine. All but the second-growth forest are natural ecosystems. A total of 551 taxa of macrofungi were recorded. Between 17% and 36% of the species in any one habitat were found only in that habitat. The most frequently encountered and ubiquitous species was Craterellus tubaeformis (Fr.) Quel., found in all years, habitats, and sites. Of the 551 taxa, only 28 were found every year, and 308 were found in only 1 year. Rare species that were recorded include Cordyceps ravenelii Berkeley & Curtis, Hygrophorus inocybiformis Smith, and Tricholoma apium Schaeffer in the dunes and Stereopsis humphreyi (Burt) Redhead in the spruce fringe. Similarities between habitats based on taxa in common showed that bog and estuarine habitats had only 9%–17% in common with each other and the other habitats, whereas dune, spruce fringe, and the two forest types shared 21%–31% of their species. Old-growth rainforest yielded approximately 4 times as many species as bog and estuarine habitats, and approximately 1.5 times as many as the other three habitats.Key words: Clayoquot Sound, Vancouver Island, macrofungi, habitats, biodiversity.


1990 ◽  
Vol 38 (3) ◽  
pp. 261 ◽  
Author(s):  
AW Graham ◽  
MS Hopkins

The size and floristic composition of soil seed banks under four adjacent, unlogged and structurally different rainforest types were assessed by exposing 17 surface soil samples (to 40mm depth) to germination-house conditions. The mean size of the seed bank in the undisturbed forest types was 240 seeds m-2 (s.d. 139). Seeds of secondary species dominated the soil seed banks in all forest types, although weed seeds constituted only 0.6-4.0%. Some forest types had characteristic component secondary species in the buried seed bank. Agglomerative classification and multidimensional scaling analysis of quantitative sample data indicated that the parent structural-environmental forest type was the dominant influence in determining composition of the soil seed banks. Comparisons of the seed banks of the intact rainforest with those of nearby disturbed forests showed the former to be 35 to 50% smaller in total size, and lacking in some distinctive secondary species. It was concluded that disturbance, both within and adjacent to rainforest, may influence soil seed bank compositions, and hence future patterns of regeneration.


1997 ◽  
Vol 54 (1) ◽  
pp. 1-38 ◽  
Author(s):  
M. T. Nascimento ◽  
J Proctor ◽  
D. M. Villela

Maracá is a riverine island located in the Rio Uraricoera in Roraima State (Brazil) and has an area of about 100,000ha. A forest type dominated by Peltogyne gracilipes Ducke (Caesalpiniaceae) occurs on Maracá Island on a range of soil types. This study compares the structure, floristic composition and soils of the Peltogyne forest with the most widespread lowland forest type on Maracá. Three 0.25ha plots were set up in each of three forest types: Peltogyne-rich forest (PRF), Peltogyne-pooi forest (PPF) and forest without Peltogyne (FWP). Within each plot all trees (≤ 10cm dbh) were recorded. Seedlings and saplings were sampled in subplots of 2m × 1m (seedlings) and 4m × 4m (saplings). In the PPF and FWP, Sapotaceae were the most important family with the highest relative dominance and relative density values. Caesalpiniaceae showed high values in the PRF and PPF. Licania kunthiana, Pradosia surinamensis and Simarouba amara occurred in the canopy layer in all the forest types. Peltogyne dominated the canopy in the PRF and comprised 20% of stems and 53% of the total basal area of all trees ≥ 10cm dbh, and 91% of the stems and 97% of the total basal area of individuals ≥ 50cm dbh. In PPF, Lecythis corrugata and Tetragastris panamensis were the most abundant species, followed by Peltogyne. In the FWP the most abundant trees (≥ 10cm dbh) were Licania kunthiana and Pradosia surinamensis. In all forest types, the soils were sandy and acid with low concentrations of extractable phosphorus and exchangeable cations, but the soils under PRF were notably richer in magnesium.


1992 ◽  
Vol 5 (1) ◽  
pp. 61-71 ◽  
Author(s):  
S. Rob Gradstein ◽  
Noris Salazar Allen

A bryophyte inventory along an altitudinal gradient on Cerro Pirre (1200 m), Darién National Park, Panama, demonstrates that the different rain forest types along the gradient (inundatedlowland, hillside-lowland, submontane, montane elfin forest) have very different species assemblages. The montane forest has the largest number of exclusive species and the largest bryophyte biomass. Species richness is greatest in the submontane forest. The bryophyte flora of Cerro Pirre is not exceedingly rich in species owing to the rather low elevation of the mountain and the seasonal climate in the adjacent coastal plain. Nevertheless, the distinct altitudinal diversification and the occurrence of a considerable number of rare hepatic taxa, demonstrate the importance of Darién National Park as an area of plant conservation. Forty hepatic species are reported as new to Panama.


2001 ◽  
Vol 17 (6) ◽  
pp. 809-832 ◽  
Author(s):  
BERNARD GUILLET ◽  
GASTON ACHOUNDONG ◽  
JOSEPH YOUTA HAPPI ◽  
VÉRONIQUE KAMGANG KABEYENE BEYALA ◽  
JACQUES BONVALLOT ◽  
...  

In an area of savanna-forest (S-F) mosaic of Cameroon, at Kandara near Bertoua, an enclosed savanna bordered by young semi-deciduous forests was selected for detailed studies of vegetation and soil carbon isotope compositions with a view to estimating the rate of forest advance into savannas. Forest floristic composition and structure were analysed in small plots along two S-F transects and within two large stands. Tree species counts and basal area (BA) measurements gave convergent results defining (1) an edge forest with low BA values that forms an irregular strip parallel to the S-F border, (2) a large colonization zone zone composed of pioneer species (Albizia species, with individuals of very large diameter) and (3) a mature forest composed of abundant Rinorea individuals and large individuals of Triplochiton scleroxylon and Piptadeniastrum africanum. Carbon stable isotopes were deter mined from organic matter of soil profiles sampled at various depths in savanna, colonization-zone and mature forest. In the deep soil horizons (40-50 cm) of the colonization-zone profiles, δ13C values similar to those of the present savanna reveal the past existence of a large-tree savanna. In subsurface horizons (15-20 cm), δ13C values intermediate between those of savanna and mature forest prove the encroachment of the forest ecosystem on savanna. Using 14C measurements, the mean residence time (MRT) of soil organic matter of these last horizons was determined with precision owing to the atmospheric 14C pulse from nuclear bomb tests prior to 1964. By assuming an exponential age distribution of organic compounds and by taking account of MRT and remaining carbon from the savanna, the coloniza tion zone was found to be 60-80 y old. The age of the colonization zone being the same near the present savanna and near the mature forest, it seems that the forest advance was probably not a linear process but would result from the coalescence of Albizia thickets born in savanna.


2017 ◽  
Vol 33 (4) ◽  
pp. 261-269 ◽  
Author(s):  
Eráclito Rodrigues de Sousa-Neto ◽  
Sílvia Rafaela Machado Lins ◽  
Susian Christian Martins ◽  
Marisa de Cássia Piccolo ◽  
Maurício Lamano Ferreira ◽  
...  

Abstract:Litterfall is one of the most important pathways through which nutrients are recycled in the terrestrial biosphere. In tropical soils, which are generally low in essential nutrients such as phosphorus and cations, the flux of nutrients through litterfall is particularly important to sustaining CO2-uptake capacity; however, questions remain over the role of altitude in altering litter nutrient cycling rates among tropical forest ecosystems. Here we examine litterfall, carbon (C), nitrogen (N) and phosphorus (P) fluxes through litterfall over an altitudinal gradient in the coastal Atlantic Forest located on the northern coast of the State of São Paulo, Brazil. Litterfall was collected twice a month for 1 y (April 2007–March 2008) using 30 litter traps placed in four different forest types arrayed by altitude – coastal forest (sea level), lowland forest (50–200 m asl), submontane forest (300–500 m asl) and montane forest (1000 m asl). Litterfall mass-fluxes decreased with increasing altitude, from ~9 Mg ha−1 in lowland forests to 7 Mg ha−1 in higher-altitude ecosystems. Contribution of reproductive organs to litterfall was significantly greater in lower than in higher altitudes. Litterfall N and P fluxes were higher in the lowland forest vs. other forest types, pointing to strong altitudinal controls over nutrient cycling. Furthermore, nitrogen-use efficiency (NUE) was lower and litter δ15N was higher in the lowland site providing additional evidence for lack of N constraints to productivity in lowland of the south-eastern Atlantic Forest.


Q'EUÑA ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 39-50
Author(s):  
Sufer Marcial Baez Quispe ◽  
Jorge Santiago Garate Quispe

Resumén Se presenta un análisis y comparación de la diversidad, estructura y composición florística de dos tipos de bosque (de tierra firme e inundable) en dos concesiones de conservación en la Zona de Amortiguamiento de la Reserva Nacional Tambopata (Madre de Dios, Perú). Se instalaron 2 parcelas de 10 m x 500 m (0,5 ha) por tipo de bosque, donde se inventarió todos los individuos con un diámetro a la altura del pecho (DAP) ≥ 10 cm. Se realizó la caracterización estructural de ambos tipos de bosque, se calculó la diversidad en ellos y se estudió la similitud entre ellos. Los resultados sugieren diferencias entre los dos tipos de bosque en términos de abundancia, dominancia, estructura y composición florística de acuerdo con otros estudios en la Amazonia. La diversidad de especies fue alta en el bosque de tierra firme (α-Fischer 84,4–57,4 y H' 4,0–4,5) y baja en el bosque inundable (α-Fischer 39.9 – 42.4, H' 3.3 – 3.4). Arecaceae fue la familia más importante en los bosques inundables, mientras que Moraceae fue la familia más importante en los bosques de tierra firme. Ficus gomelleira, Pterocarpus amazonum, Hevea guianensis, y Socratea exorrhiza fueron las especies más importantes en los bosques de tierra firme, mientras que Iriartea deltoidea, Otoba parvifolia y Pseudolmedia laevis, fueron las más importantes en los bosques inundables. La composición florística fue diferente entre los dos tipos de bosque, con 19,3 % de similitud en promedio (distancia de Bray-Curtis). Nuestros resultados coinciden con los obtenidos en otras investigaciones para la Amazonía Peruana. AbstractThe aim of this study was to compare and analyze the diversity, structure and floristic composition of two forest types at buffer zone of the Tambopata National Reserve (Madre de Dios). Two plots per forest types of 10 m x 500 m (0.5 ha) were used, where all individuals with a diameter at the breast height DBH ≥ 10 cm were inventoried. The total height (HT) and DBH of all tree individuals were measured. In the structural analysis, DBH size classes, density, dominance, and the importance index were calculated. We calculated the Shannon-Weaver index, α-Fischer index, and Bray-Curtis distance to evaluate the species diversity and similarity between the two forest types. The results suggest differences between forest types in terms of abundance, dominance, structure and floristic composition in agreement with other studies in the Amazonia. The species diversity is higher the terra firme forest (α-Fischer 84.4–57.4 y H' 4.0–4.5) than in the flooded forest (α-Fischer 39.9 – 42.4 y H' 3.3 – 3.4). The Arecaceae was the most important family in the flooded forest while the Moraceae was the most important family in terra firme forest. Ficus gomelleira, Pterocarpus amazonum, Hevea guianensis, and Socratea exorrhiza were the most important species in terra firme 


2021 ◽  
Author(s):  
Monica Kaushik ◽  
Sutirtha Dutta ◽  
Gopal S. Rawat ◽  
Pratap Singh ◽  
Dhananjai Mohan

AbstractMost tropical forests have undergone commercial logging. Even where logging has ceased, subsistence harvest of forest resources often persists especially in South-East Asia. Understanding of impacts of frequent forest resources extraction in areas recovering from past selective logging would be essential for designing the appropriate management interventions.We studied the impacts of current chronic anthropogenic disturbances (hereafter CAD) and past selective logging on vegetation structure, diversity, and regeneration, and the invasion of a non-native shrub, Lantana camara, in three major forest types in the Himalayan foothills, India. We analyzed field data on intensity of CAD and vegetation variables, collected from 269 stratified random plots, using ordination and generalized linear (mixed) modeling approaches.Our results, based on 2758 adult trees of 54 species, showed that forest types differed in disturbance regimes depending on protection level and availability of fodder tree species. Intensity of CAD depended on proximity to settlements (for livestock related disturbances). Whereas selective logging, including firewood collection, was associated with land protection status. Selective logging reduced the extent of mature forest but facilitated regeneration, thereby promoting secondary forest features such as tree density and canopy cover. In contrast, the interaction between lopping and selective logging was negatively associated with regeneration. Past logging facilitated L. camara invasion in Dry and Hill forests but not in Moist forest. Finally, while selective logging marginally enhanced tree diversity, CAD reduced native shrub diversity.Our study demonstrates that selective logging followed by CAD arrest forest recovery, as evident from the suppression of mature forest elements, loss of shrub biomass, reduced regeneration rate, and facilitation of invasive species. To abate these impacts, alternative livelihood/subsistence options that sustain forests and local communities should be explored. Additionally, CAD management should be site-specific as local ecological contexts modify their impacts on forests.


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