scholarly journals Habitat disturbance and small mammal richness and diversity in an Atlantic rainforest area in southeastern Brazil

2006 ◽  
Vol 66 (4) ◽  
pp. 983-990 ◽  
Author(s):  
C. F. Vera y Conde ◽  
C. F. D. Rocha

Since disturbance is an important ecological factor affecting species diversity in natural environments, the increasing human occupation rate in Brazilian Atlantic rainforest, which supports about 50% of Brazil's human population, has resulted in intense habitat degradation and fragmentation. Within this rainforest, animal and plant species have been lost at a high rate, and biological and diversity is presently vulnerable. Various animals community studies along a gradient of environmental disturbances have shown that the highest species diversities occur in habitats with intermediate levels of disturbance frequency and intensity. In the present study, which was carried out in the Atlantic forest of Ilha Grande (23° 11' S and 44° 12' W), an island located on the southern coast of Rio de Janeiro State, southeastern Brazil, we estimated species richness, diversity, and abundance of small mammals in three forest areas having different disturbance levels. This was done, in each of these areas and in an anthropic area that they surround, by establishing trails 200 m long, in which points were marked at 20 m intervals. The work involved a total effort of 4800 trap/nights. We also measured some habitat variables at each site in order to evaluated their disturbance levels. Our data showed that the two most conserved forests had the lower species richness and small mammal diversity, while in the anthropic area wild species were absent. The forest with an intermediary level of disturbance showed higher values for species richness and diversity, with the anthropic area presenting the highest disturbance level.

2007 ◽  
Vol 67 (1) ◽  
pp. 179-186 ◽  
Author(s):  
PS. D’Andrea ◽  
R. Gentile ◽  
LS. Maroja ◽  
FA. Fernandes ◽  
R. Coura ◽  
...  

This study reports 2 years of the population dynamics and reproduction of a small mammal community using the removal method. The study was conducted in a rural area of the Atlantic Forest, in Sumidouro, Rio de Janeiro State, Brazil. The population sizes, age structure and reproduction were studied for the four most common species in the study area. The overall diversity was 1.67 and ranged between 0.8 to 1.67. The species richness was 13 considering the whole study. The most abundant species were the rodents Nectomys squamipes (n = 133), Akodon cursor (n = 74), Oligoryzomys nigripes (n = 25) and the marsupials Didelphis aurita (n = 58) and Philander frenatus (n = 50). Seven other rodents were captured once: Necromys lasiurus, Akodon montensis, Sooretamys angouya, Oecomys catherine, Oxymycterus judex, Euryzygomatomys spinosus and Trinomys iheringi. There were higher peaks for diversity and species richness during the winter (dry) months, probably due to higher food availability. The marsupials had a seasonal reproduction with highest population sizes at the end of the rainy seasons. Nectomys squamipes reproduced mostly during rainy periods. Akodon cursor reproduced predominantly in the winter with the highest population peaks occurring during this season. The analysis of the population dynamics of the rodent species indicated that no species behaved as an agricultural pest, probably due to the heterogeneous landscape of high rotativity of vegetable cultivation. Rodent populations were more susceptible to the removal procedure than marsupial ones.


2002 ◽  
Vol 62 (3) ◽  
pp. 419-425 ◽  
Author(s):  
E. B. BITTENCOURT ◽  
C. F. D. ROCHA

We studied the ectoparasite and the Amblyopinini beetle fauna associated with four small mammal species of the Atlantic Rainforest of Ilha Grande, an island located off the southern Rio de Janeiro State Coast, Southeastern Brazil, analyzing to what extent the parasites were specific to each region of the host body. During the study, a total of 90 individual rodents were captured: 61 Proechimys iheringi Thomas, 1911 (Echymyidae), 22 Sciurus aestuans (Thomas, 1901) (Sciuridae), 4 Oxymycterus sp. (Waterhouse, 1837), and 2 Nectomys squamipes (Brants, 1827) (Sigmodontinae). The data showed that the ectoparasites and Amblyopinini on some rodent hosts in Ilha Grande tend to prefer particular host body sites, and that some ectoparasite species sites may overlap owing to their inaccessibility to the host.


The Holocene ◽  
2017 ◽  
Vol 27 (8) ◽  
pp. 1067-1077 ◽  
Author(s):  
Sandra Bañuls-Cardona ◽  
Patricia Martín Rodríguez ◽  
Juan Manuel López-García ◽  
Juan Ignacio Morales ◽  
Gloria Cuenca-Bescós ◽  
...  

The human impact on the environment in the Holocene has usually been characterized on the basis of palaeobotanical records, but attempts to distinguish the anthropogenic impact from natural events in landscape evolution have been the subject of much debate in recent years. The aim of this paper is to analyse small-mammal diversity and the presence of synanthropic species, whose small size makes them more sensitive to any changes in their environment that may occur. This study has allowed us to characterize palaeoclimatic and palaeoenvironmental changes, recording small changes whether resulting from a human influence or otherwise. Our object of study is El Mirador cave, which has a sequence with a well-documented human occupation extending from 7200 to 3000 cal. BP. The study has led us to differentiate two phases. In one phase, we can see small changes in diversity related to climatic oscillations from ca. 7200 to 6800 cal. BP, while in the second phase, lasting from ca. 6800 to 3000 cal. BP, the changes in diversity and in the assemblage of synanthropic species are associated with human economic strategies. Moreover, we distinguish which kinds of economic activity (crop and livestock farming) have influenced these changes, because some small-mammal species are influenced, positively or negatively, by environmental changes based on crop farming and animal husbandry. All this information is contrasted with other archaeological proxies, such as the large-mammal and palaeobotanical assemblages from El Mirador cave. Furthermore, this integrative analysis has made it possible to identify the existence of altered environments more generally throughout the Iberian Peninsula from ca. 6000 cal. BP. It additionally confirms the theory of low human occupation intensity in the northern Meseta and in high mountainous areas during the early Neolithic.


2007 ◽  
Vol 23 (4) ◽  
pp. 419-425 ◽  
Author(s):  
J.-F. Mauffrey ◽  
C. Steiner ◽  
F. M. Catzeflis

Neotropical species richness is often estimated using accumulation or rarefaction curves and extrapolations based on various methods, but the efficacy of these methods is rarely tested. We used both a time-limited trapping session and previous knowledge of the mammal fauna from a site in French Guiana to validate these different methods. Three currently used extrapolation models were tested on our data. In a 2.5-mo trapping period we caught 75 individuals representing 18 small non-volant mammal species in three different habitats. We found that for comparable trapping efforts, village edges presented a higher abundance and species richness than primary and secondary forests. Species richness extrapolations using current models demonstrated that the exponential dependence model fits the known diversity of the site better, although this model is usually applied to large geographic areas and to relatively poorly documented taxa. Both Clench equation and linear dependence models underestimate small-mammal species richness in our study. We finally emphasize the interest of sampling in such edges surrounded by either primary or secondary forest, to maximize the probability of trapping rare species.


Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1107
Author(s):  
Anamaria Lazăr ◽  
Ana Maria Benedek ◽  
Ioan Sîrbu

Small mammals are key components of forest ecosystems, playing vital roles for numerous groups of forest organisms: they exert bottom-up and top-down regulatory effects on vertebrate and invertebrate populations, respectively; they are fungus- and seed-dispersers and bioturbators. Therefore, preserving or restoring the diversity of small mammal communities may help maintain the functions of these ecosystems. In Romania, a country with low-intensity forest management and a high percentage of natural forests compared to other European countries, an overview of forest small mammal diversity and habitat type use is lacking, and our study aimed to fill this gap. We also aimed to partition the total small mammal diversity of Romanian forests into the alpha (plot-level), beta, and delta (among forest types) diversities, as well as further partition beta diversity into its spatial (among plots) and temporal (among years) components. We surveyed small mammals by live trapping in eight types of forest across Romania. We found that small mammal abundance was significantly higher in lowland than in mountain forests, but species richness was similar, being associated with the diversity of tree canopy, with the highest values in mixed forests. In contrast, small mammal heterogeneity was related to overall habitat heterogeneity. As predicted, community composition was most distinct in poplar plantations, where forest specialists coexist with open habitat species. Most of the diversity was represented by alpha diversity. Because of strong fluctuations in population density of dominant rodents, the temporal component of beta heterogeneity was larger than the spatial component, but species richness also presented an important temporal turnover. Our results show the importance of the time dimension in the design of the surveys aiming at estimating the diversity of small mammal communities, both at the local and regional scales.


2007 ◽  
Vol 28 (1) ◽  
pp. 166-169 ◽  
Author(s):  
Joaquim Vicente ◽  
Davor Vrcibradic ◽  
Charles Bursey

AbstractWe studied the helminth assemblage of a population of the iguanian lizard Enyalius bilineatus from an Atlantic forest area in Espírito Santo state, southeastern Brazil. Eighteen of the 27 individuals examined (66.7%) harbored helminths. A total of six helminth species were found, including acanthocephalan cystacanths (Centrorhynchidae), and five species of nematodes: Physaloptera lutzi, P. retusa, Oswaldocruzia benslimanei, Rhabdias sp. and larvae of an indeterminate species of Acuariidae. In the context of helminth assemblages from Neotropical iguanian lizards, that of E. bilineatus was similar in some parameters (such as species richness and number of core species) to those of other forest-dwelling species, but generally poorer when compared to open-habitat hosts.


2012 ◽  
Vol 49 (2) ◽  
pp. 115-133
Author(s):  
Mateusz Ciechanowski ◽  
Jan Cichocki ◽  
Agnieszka Ważna ◽  
Barbara Piłacińska

Abstract We studied species composition of assemblages of small mammals (rodents and shrews) inhabiting Polish 25 ombrotrophic mires and quaking bogs in several regions in order to reveal characteristic features of their quantitative structure and compare them between regions, internal zones of the bog habitats, and different levels of anthropogenic degradation. We reviewed also all published results of small-mammal trapping in such habitats. Mammals were captured in pitfalls, snap traps and live traps on 12 bogs of the Pomerania region, 4 bogs of the Orawa-Nowy Targ Basin (Kotlina Orawsko-Nowotarska), 3 bogs in the Świętokrzyskie Mts, and 6 bogs in Wielkopolska and the Lubusz Land. Additionally, we included materials collected from Barber traps (pitfalls) used during studies of epigeic invertebrates on 4 bogs. In total, 598 individuals of 12 species were collected. The number of pitfall captures per 100 trapnights was very low (7.0-7.8), suggesting low population density. Shrews predominated among mammals captured in pitfalls, and the assemblage structure appeared to be similar to impoverished forest fauna, slightly enriched with ubiquitous species from meadows and agroecosystems, with a very small percentage of typical wetland species (Neomys fodiens, Neomys anomalus, Microtus oeconomus). Rodents (mostly Myodes glareolus) predominated only in samples obtained by live and snap traps. Pygmy shrew Sorex minutus was the most numerous species at most sites, sometimes being the only small mammal in that habitat, especially in well-preserved, treeless parts of bogs, dominated by Sphagnum peatmoss. The dominance and high constancy of S. minutus appear to be a characteristic feature of small-mammal assemblages inhabiting ombrotrophic mires, at least in some regions of Central and Western Europe. Enrichment of the fauna with other species might be related to either improved trophic conditions (by contact with mineralized ground waters) or habitat degradation (by peat mining, drainage, and subsequent secondary succession).


Geology ◽  
2012 ◽  
Vol 41 (2) ◽  
pp. 267-270 ◽  
Author(s):  
J. M. Lopez-Garcia ◽  
H.-A. Blain ◽  
J. I. Morales ◽  
C. Lorenzo ◽  
S. Banuls-Cardona ◽  
...  

2014 ◽  
Vol 74 (1) ◽  
pp. 199-204 ◽  
Author(s):  
TA Dorigo ◽  
T Maia-Carneiro ◽  
M Almeida-Gomes ◽  
CC Siqueira ◽  
D Vrcibradic ◽  
...  

Our study aimed to add information about the diet and endoparasites of Enyalius brasiliensis from an Atlantic Rainforest remnant in the state of Rio de Janeiro, southeastern Brazil. Regarding diet, E. brasiliensis consumed arthropods, with caterpillars and beetles being the most important preys. Regarding helminth parasites, overall prevalence was low (9.5%), with 238 nematodes of the genus Physaloptera found in the stomach of one specimen and one nematode of the genus Rhabdias inside the lung of another. Our results corroborate the observations of previous studies that indicate that lizards of the genus Enyalius tend to feed mainly on relatively large-bodied arthropods and to harbour depauperate endoparasite fauna.


Phytotaxa ◽  
2015 ◽  
Vol 224 (3) ◽  
pp. 291 ◽  
Author(s):  
Luiz Armando De Araújo Góes-Neto ◽  
Gustavo Heringer ◽  
Alexandre Salino

 A species of Selaginella from Parque Nacional do Caparaó, in Espírito Santo State, southeastern Brazil, is described as new to the science: Selaginella salinoi grows on rocks in Atlantic Rainforest vegetation at ca. 1200 m. The description includes photos of live plants and, scanning electron micrographs.


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