scholarly journals Tree Strata Structure in an Ecotone among the Amazon Forest Types: A Comparative Study

2019 ◽  
Vol 65 (6) ◽  
pp. 693-702
Author(s):  
Aline Canetti ◽  
Evaldo Muñoz Braz ◽  
Patrícia Póvoa de Mattos ◽  
Afonso Figueiredo Filho ◽  
Renato Olivir Basso

AbstractThis work aimed to describe the structural dynamics of the Transitional Amazonian Forest and to evaluate whether the most abundant tree species present a structural pattern. As it is an ecotone composed of two forest types, a high composition complexity is expected. Forest analysis occurred with six 100 percent inventories data considering all trees with diameter at breast height ≥15.7 in., totalizing over 13 000 ac. The study areas were compared in terms of tree density, number of species, and importance value of the most abundant species. The Morisita index and the cluster analysis tested the forests similarity. We also evaluated the importance value of species in the upper and middle strata. Differences between study areas were detected regarding tree density and number of species. However, the forests presented more than 75 percent similarity and were grouped in three structural clusters. Some species showed alternations of dominance in the middle and upper strata. Although the forest is an ecotone, the trees had a structural pattern, where the same species dominate large areas, allowing us to apply the results on a huge scale.

2015 ◽  
Vol 27 ◽  
pp. 72-77
Author(s):  
Laxmi J Shrestha ◽  
Mohan Devkota

A year round phytosociological study was carried out in 2012 to study different forest types in Pashupati Sacred Grove in Kathmandu Valley. Concentric circular plots (n-19) were laid down along eight parallel transects, 100 m apart from each other, traversing north and south passing through various vegetations. Our results showed that the grove had experienced change in forest types over the time period. Three forest types namely Schima-Pyrus, Moist (Myrsine- Persea) and Mixed (Quercus-Myrsine) were identified based on the importance value Index (IVI) of tree species instead of Myrsine-Schima forest which had once dominated the grove. Tree density greatly changed in different forest types and showed strong correlation between canopy cover and tree density, supporting the results of previous studies. J. Nat. Hist. Mus. Vol. 27, 2013: 72-77


IAWA Journal ◽  
2000 ◽  
Vol 21 (3) ◽  
pp. 277-292 ◽  
Author(s):  
D.W. Woodcock ◽  
G. Dos Santos ◽  
C. Reynel

The Tambopata region of the southern Peruvian Amazon supports a high diversity of both woody plants and forest types. Woods collected from low riverside vegetation, floodplain forest, clay-soil forest on an upper terrace, sandy-soil forest, and swamp forest provide an opportunity to test for significant differences in quantitative anatomical characters among forest types. Vessel-element length in floodplain-forest trees is significantly greater than in the other forest types. Specific gravity is lower in the two early-successional associations (low riverine forest and mature floodplain forest). Vessel diameter and density do not show significant differences among forest types and may be responding to overall climate controls. These two characters, however, show a pattern of variation within a transect extending back from the river along a gradient of increasing substrate and forest age; in addition, sites characterized by frequent flooding or presence of standing water lack vessels in the wider-diameter classes. The six characters analyzed show distributions that are, with the exception of wood specific gravity, significantly nonnormally distributed, a consideration that may be important in representing characteristics of assemblages of taxa. The degree of variability seen in some of the quantitative characters shows the importance of either basing analysis on adequate sample sizes or identifying robust indicators that can be used with small samples.


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.


2006 ◽  
Vol 33 (3) ◽  
pp. 256-262 ◽  
Author(s):  
R. SAGAR ◽  
J.S. SINGH

Dry tropical forest communities are among the world's most threatened systems and urgent measures are required to protect and restore them in degraded landscapes. For planning conservation strategies, there is a need to determine the few essential measurable properties, such as number of species and basal area, that best describe the dry forest vegetation and its environment, and to document quantitative relationships among them. This paper examines the relationships between forest basal area and diversity components (number of species and evenness) for a disturbed dry tropical forest of northern India. Data were collected from five sites located in the Vindhyan dry tropical forest of India, selected on the basis of satellite images and field observations to represent the entire range of conditions in terms of canopy cover and disturbance regimes. These sites represented different communities in terms of species composition. The forest was poorer in species richness, and lower in stem density and basal area than wet forests of the tropics. Across sites (communities), the diversity components and tree density were positively related with total tree basal area. Considering basal area as a surrogate of biomass and net production, diversity is found to be positively associated with productivity. A positive relationship between basal area, tree density and species diversity may be an important characteristic of the dry forest, where recurring disturbance does not permit concentration of biomass or stems in only a few strong competitors. However, the relationships of basal area with density, alpha diversity and evenness remain statistically significant only when data from all sites, including the extremely disturbed one, are used in the analysis. In some sites there was a greater coefficient of variation (CV) of basal area than in others, attributed to patchy distribution of stems and resultant blanks. Therefore, to enhance the tree diversity of these forests, the variability in tree basal area must be reduced by regulating local disturbances. Conservation activities, particularly fuelwood plantations near human settlements, deferred grazing and canopy enrichment through multi-species plantations of nursery-raised or wild-collected seedlings of desirable species within the forest patches of low basal area, will be needed to attain restoration goals, but reforestation programmes will have to be made attractive to the forest-dwelling communities.


Author(s):  
Shiming Zhu ◽  
Lingling Xiao ◽  
Li Xue ◽  
Yue Zhang ◽  
Xiguang Dong

2015 ◽  
Vol 7 (15) ◽  
pp. 8272 ◽  
Author(s):  
Girish Gogoi ◽  
Vipin Parkash

<p>Hollongapar Gibbon Wildlife Sanctuary is comprised of five distinct compartments.  A total of 138 species of gilled mushrooms belonging to 48 genera, 23 families, five orders of the class Agaricomycetes, division Basidiomycota, have been collected and analyzed. The order Agaricales was was found with the highest number of species (113), followed by Russulales (14), Polyporales (5), Cantharellales (4) and Boletales (2). The species <em>Coprinellus disseminatus </em>and <em>Megacollybia rodmani</em> have shown the highest (8.26) and the lowest density (0.05), respectively.  A total of 24 species, e.g., <em>Termitomyces albuminosus, Marasmius curreyi, Marasmiellus candidus, Leucocoprinus medioflavus, Mycena leaiana, Hygrocybe miniata, Collybia chrysoropha, Gymnopus confluens</em> were common with frequency percentage of 11.9, whereas <em>Megacollybia rodmani</em> with less frequency percentage (2.4) was found only in few quadrates of the sanctuary.  The highly abundant species were <em>Termitomyces medius</em> (91.7) and <em>Coprinellus disseminatus </em>(86.8), and less abundant species were <em>Psilocybe wayanadensis</em> (1.0) and <em>Lepiota</em> sp. (1.0) in the study site.  The order of the species richness index (<em>R</em>) compartment wise was 2&gt;3&gt;4&gt;5&gt;1. Both the Shannon diversity index and Simpson diversity index of agarics was maximum (1.88, 0.98) in compartment 2, whereas minimum (1.72, 0.95) in compartment 1 and 5, respectively.  Moreover, the compartment 2 was found very much similar with compartment 3 and very less similar with compartment 1.</p><div> </div>


2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Do Thi Ngoc Le ◽  
Nguyen Van Thinh ◽  
Nguyen The Dung ◽  
Ralph Mitlöhner

The effects of disturbance regimes on the spatial patterns of the five most abundant species were investigated in three sites in a tropical forest at Xuan Nha Nature Reserve, Vietnam. Three permanent one-ha plots were established in undisturbed forest (UDF), lightly disturbed forest (LDF), and highly disturbed forest (HDF). All trees ≥5 cm DBH were measured in twenty-five 20 m × 20 m subplots. A total of 57 tree species belonging to 26 families were identified in the three forest types. The UDF had the highest basal area (30 m2 ha−1), followed by the LDF (17 m2 ha−1) and the HDF (13.0 m2 ha−1). The UDF also had the highest tree density (751 individuals ha−1) while the HDF held the lowest (478 individuals ha−1). Across all species, there were 417 “juveniles,” 267 “subadults,” and 67 “adults” in the UDF, while 274 “juveniles,” 230 “subadults,” and 36 “adults” were recorded in the LDF. 238 “juveniles,” 227 “subadults,” and 13 “adults” were obtained in the HDF. The univariate and bivariate data with pair- and mark-correlation functions of intra- and interspecific interactions of the five most abundant species changed in the three forest types. Most species indicated clumping or regular distributions at small scale, but a high ratio of negative interspecific small-scale associations was recorded in both the LDF and HDF sites. These were, however, rare in the UDF.


2013 ◽  
Vol 61 (4) ◽  
pp. 251-264 ◽  
Author(s):  
Ana Carolina dos Passos ◽  
Riguel Feltrin Contente ◽  
Felippe Veneziani Abbatepaulo ◽  
Henry Louis Spach ◽  
Ciro Colodetti Vilar ◽  
...  

Here we test the effects of the east-west salinity gradient in the subtropical Paranaguá Bay Estuarine Complex (PEC) on the structure of shallow water fish fauna, determined according to taxonomic (families and species) and functional composition metrics. A total of 152 species were observed. The families with the largest number of species were the Sciaenidae, Carangidae, Haemulidae and Gobiidae. The most abundant species were Atherinella brasiliensis, Harengula clupeola, Anchoa januaria and Anchoa tricolor. Marine stragglers dominated in number of species, followed by marine migrants and estuarine species. Most species were zoobenthivores, followed by piscivores and zooplanktivores. Families and species more frequently associated with estuarine conditions dominated in the mesohaline sector, and those more frequently associated with marine conditions dominated in the euhaline sector. The fish assemblages along the estuarine salinity gradient were found to be better characterized by taxonomic metrics than by functional ones. This is most likely because individuals of all functional groups inhabit all salinity sectors, and thus these metrics are not useful for differentiating assemblages along salinity gradients. Our results differ from those of other studies in tropical and subtropical estuaries, which have emphasized the importance of functional groups in determining fish assemblages along salinity gradients.


1996 ◽  
Vol 47 (6) ◽  
pp. 827 ◽  
Author(s):  
MJ Sheaves

The species richness of fishes and the distributions of six fish species were compared among four habitat types, snaggy banks, clear banks, mud banks and mid channels, in an estuary in tropical Australia. Both day and night samples were collected in fish traps, on four occasions, three months apart. On each sampling trip the highest number of species was trapped from snaggy habitats, intermediate numbers from clear banks or mud banks, and the fewest species from mid channels. Although more species occurred in night than in day samples, the pattern of difference among habitats was consistent. The probability of capture of the six most abundant species, Acanthopagrus australis, Acanthopagrus berda, Arothron manilensis, Arius argyropleuron, Epinephelus coioides and Lutjanus russelli, was compared among habitat types and between day and night samples. Overall, snag habitats tended to be associated with high probabilities of capture of a number of species, particularly A. berda and L. russelli. At night, mid channels were characterized by high numbers of A. argyropleuron. Clear and mud banks, and day samples from mid channels were associated with low numbers of most species.


Author(s):  
Marco Infusino ◽  
Concetta Calabrò ◽  
Salvatore Saitta ◽  
Stefano Scalercio

Riassunto - Gli scopi di questa ricerca sono quelli di contribuire alla conoscenza della macrolepidotterofauna della Sicilia nord-orientale e di caratterizzare la comunità presente nella Riserva Naturale Orientata “Laghetti di Marinello”. Sono stati effettuati 23 campionamenti tra dicembre 2007 e dicembre 2008 col metodo della caccia al lume. Sono stati catturati 2.537 individui appartenenti a 160 specie, tra cui Chloroclystis v-ata e Laelia coenosa, segnalate per la prima volta in Sicilia; importanti anche le segnalazioni di Calamodes subscudularia, Mythimna languida e M. joannisi, specie piuttosto rare e localizzate. Le specie più abbondanti sono state: Eilema caniola, Eublemma viridula, Idaea filicata, Dysauxes famula e Idaea seriata, che da sole rappresentano il 42% di tutta la comunità, favorite dalla presenza delle rispettive piante nutrici e dall’elevato adattamento alle condizioni climatiche del sito. Il numero di specie e i valori degli indici di diversità indicano un basso livello di biodiversità ospitata, ma la fenologia, le analisi corologica e autoecologica delle specie, insieme ai confronti effettuati con altre faune, indicano una comunità ben caratterizzata e peculiare, diretta espressione delle condizioni abiotiche e biotiche della Riserva.Abstract - Macroheterocera of the Oriented Natural Reserve “Laghetti di Marinello” (north-eastern Sicily) (Lepidoptera: Heterocera). The aim of this research is to contribute to the knowledge of the fauna of macrolepidoptera of north-eastern Sicily and to describe the community present in the Oriented Natural Reserve “Laghetti di Marinello”. 23 samples were carried out from December 2007 to December 2008 using a white vertical sheet reflecting a light source. 2.537 specimens belonging to 160 species were captured. Chloroclystis v-ata and Laelia coenosa were reported for the first time in Sicily, Calamodes subscudularia, Mythimna languida and M. joannisi, very rare and localized species, were also reported. The most abundant species were: Eilema caniola, Eublemma viridula, Idaea filicata, Dysauxes famula and Idaea seriata, which represent the 42% of the whole community and are favoured by the presence of their feeding plants and by their high adaptability to the climatic conditions of the place. The number of species and the values of the diversity indices show a low level of biodiversity, but phenology, chorological and autoecological analysis of the species, with comparisons made with other faunae, show a well characterized and peculiar community, direct expression of the abiotic and biotic conditions of the Reserve.


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