scholarly journals The spatial distribution of Hymenoptera parasitoids in a forest reserve in Central Amazonia, Manaus, AM, Brazil

2011 ◽  
Vol 71 (4) ◽  
pp. 865-871 ◽  
Author(s):  
RB. Querino ◽  
SRM. Couceiro ◽  
LO. Queiroz ◽  
AM. Penteado-Dias
Keyword(s):  
Spatial Distribution ◽  
Species Richness ◽  
Forest Canopy ◽  
Forest Ecosystems ◽  
The Other ◽  
Ecological Role ◽  
Forest Reserve ◽  
Central Amazonia ◽  
Dry Seasons ◽  
Species Richness And Abundance

Parasitoids are of great importance to forest ecosystems due to their ecological role in the regulation of the population of other insects. The species richness and abundance of parasitoids in the forest canopy and understory, both on the borders and in the interior of a tropical forest reserve in Central Amazonia were investigated. For a 12-month period, specimen collections were made every 15 days from suspended traps placed in the forest canopy and in the understory strata, both on the border and in the interior of forest areas. A total of 12,835 Hymenoptera parasitoids from 23 families were acquired. Braconidae, Diapriidae, Mymaridae, Eulophidae, and Scelionidae were the most represented in the area and strata samples. The results indicate that there were no significant differences in the species richness or abundance of Hymenoptera between the forest borders and the inner forest. The data does show that the presence of Hymenoptera is significantly greater in the understory in both the border and interior areas than in the canopy (vertical stratification). Aphelinidae and Ceraphronidae were significantly associated with the inner forest, while the other seven families with the border of the reserve. The abundance of Hymenoptera parasitoids presented seasonal variations during the year related to the rainy and dry seasons.

scholarly journals Salinity and freshwater discharge determine rotifer distribution at the Mossoró River Estuary (Semiarid Region of Brazil)

2010 ◽  
Vol 70 (3) ◽  
pp. 551-557 ◽  
Author(s):  
AMA. Medeiros ◽  
JEL. Barbosa ◽  
PR. Medeiros ◽  
RM. Rocha ◽  
LF. Silva
Keyword(s):  
Species Richness ◽  
Rainy Season ◽  
Salinity Gradient ◽  
River Estuary ◽  
Positive Influence ◽  
Freshwater Discharge ◽  
The Other ◽  
Semiarid Region ◽  
Inverse Estuary ◽  
Species Richness And Abundance

The present study aimed at evaluating differences in rotifer distribution in three estuarine zones in an inverse estuary located in the Semiarid Region of Brazil. Zones were chosen based on their proximity to the ocean and river border as a means of reflecting a horizontal salinity gradient. High freshwater discharge during the rainy season was the major determinant of rotifer composition. On the other hand, due to higher salinity values during the dry season, very low values of species richness and abundance were observed in all zones. Therefore, the study highlights the constraints of salinity and the positive influence of seasonality and river proximity on rotifer species in a semiarid estuarine environment.

scholarly journals Characterizing Tree Spatial Distribution Patterns Using Discrete Aerial Lidar Data

2020 ◽  
Vol 12 (4) ◽  
pp. 712 ◽  
Author(s):  
Xiaofei Wang ◽  
Guang Zheng ◽  
Zengxin Yun ◽  
L. Monika Moskal
Keyword(s):  
Spatial Distribution ◽  
Point Processes ◽  
Forest Canopy ◽  
Forest Ecosystems ◽  
Urban Forest ◽  
Pair Correlation ◽  
Distribution Patterns ◽  
Individual Tree ◽  
Spatial Distribution Patterns ◽  
Water Cycles

Tree spatial distribution patterns such as random, regular, and clustered play a crucial role in numerical simulations of carbon and water cycles and energy exchanges between forest ecosystems and the atmosphere. An efficient approach is needed to characterize tree spatial distribution patterns quantitatively. This study aims to employ increasingly available aerial laser scanning (ALS) data to capture individual tree locations and further characterize their spatial distribution patterns at the landscape or regional levels. First, we use the pair correlation function to identify the categories (i.e., random, regular, and clustered) of tree spatial distribution patterns, and then determine the unknown parameters of statistical models used for approximating each tree spatial distribution pattern using ALS-based metrics. After applying the proposed method in both natural and urban forest sites, our results show that ALS-based tree crown radii can capture 58%–77% (p < 0.001) variations of visual-based measurements depending on forest types and densities. The root mean squared errors (RMSEs) of ALS-based tree locations increase from 1.46 m to 2.51 m as the forest densities increasing. The Poisson, soft-core, and hybrid-Gibbs point processes are determined as the optimal models to approximate random, regular, and clustered tree spatial distribution patterns, respectively. This work provides a solid foundation for improving the simulation accuracy of forest canopy bidirectional reflectance distribution function (BRDF) and further obtain a better understanding of the processes of carbon and water cycles of forest ecosystems.

scholarly journals Diversity and distribution of testate amoebae (Amoebozoa, Rhizaria) in reservoirs, Northeastern Bulgaria

2018 ◽  
Vol 5 (2) ◽  
pp. 90-99
Author(s):  
Rositsa Davidova ◽  
Senay Sevginov
Keyword(s):  
Regression Analysis ◽  
Species Richness ◽  
Diversity Index ◽  
Taxonomic Diversity ◽  
Testate Amoebae ◽  
The Other ◽  
Water Volume ◽  
Species Richness And Abundance ◽  
Relationship Of ◽  
The Relationship

Abstract The aim of the study is to describe the testate amoebae fauna in seven reservoirs in the Northeastern Bulgaria and to investigate the relationship of taxonomic diversity and abundance of these organisms to the some characteristics of the reservoirs. A total of 52 species, varieties and forms belonging to 15 genera were identified in the benthal of the coastal zone. There are significant differences in species richness and abundance between the testacea of different reservoirs. Number of taxa was significantly higher in the Beli Lom (29 species and 12 genera) and Loznitsa (22 species and 13 genera). Most of the reservoirs - Kara Michal, Bogdantsi, Isperih, Lipnik and Brestovene have extremely poor fauna compared to other similar reservoirs. This is confirmed by the low values of the Shannon-Weaver diversity index, which varied between 1.04 and 2.396, as well as by the other indices used to assess the environmental conditions in the reservoirs. The data of the regression analysis showed that a relation between age, surface area and water volume of the reservoirs and the species richness and abundance of testacea is not established.

scholarly journals Effect of environmental parameters on squamate reptiles in an urban forest fragment in central Amazonia

2020 ◽  
Vol 50 (3) ◽  
pp. 239-245
Author(s):  
Thais ALMEIDA-CORRÊA ◽  
Luciana FRAZÃO ◽  
Diogo Magalhães COSTA ◽  
Marcelo MENIN ◽  
Igor Luis KAEFER
Keyword(s):  
Species Richness ◽  
Urban Forest ◽  
Structural Parameters ◽  
Environmental Parameters ◽  
Forest Fragments ◽  
Forest Fragment ◽  
Tropical Biodiversity ◽  
Central Amazonia ◽  
Regional Species Pool ◽  
Species Richness And Abundance

ABSTRACT The increasing urbanization of the Amazonian biome has promoted the creation of several forest fragments surrounded by an urban matrix, but the relationship of animal assemblages to the urban environment, especially in forest fragments, is poorly known. Here we aimed to 1) determine the composition of the squamate fauna of the largest urban forest fragment from central Amazonia, in the Brazilian city of Manaus, and 2) evaluate the influence of environmental parameters on assemblage diversity. We sampled 10 standardized riparian plots through visual search in six surveys between 2008/09 and 2015, totaling 360 observer-hours. We found 15 species of lacertoids (lizards and amphisbaenians) and seven species of snakes through active search. After considering occasional encounters and search in museum collections, we recorded a total of 24 lacertoid and 22 snake species. Multiple regression models indicated that species richness and abundance of individuals increased with the distance from the edge of the fragment, while other structural parameters of the environment did not affect the assemblage. We conclude that this forest fragment 1) consists of a subset of the regional species pool, and 2) undergoes reduction of species richness and abundance of individuals from the center to the borders. This and additional urban forest fragments should be continually monitored in order to evaluate their long-term role in maintaining the tropical biodiversity.

Relationship between turbidity and the benthic community in the preserved Montebello Lakes in Chiapas, Mexico

2020 ◽  
Vol 71 (7) ◽  
pp. 824
Author(s):  
Inari Sosa-Aranda ◽  
Luis Zambrano
Keyword(s):  
Cluster Analysis ◽  
Species Richness ◽  
National Park ◽  
Benthic Communities ◽  
Benthic Macroinvertebrate ◽  
Gradual Change ◽  
Secchi Disc ◽  
Secchi Disc Depth ◽  
Dry Seasons ◽  
Species Richness And Abundance

One of the consequences of increased turbidity in lakes is the modification of the structure of the benthic macroinvertebrate community. To understand this relationship, we evaluated 13 lakes in the Montebello Lakes National Park in Chiapas. The lakes have been affected by gradual eutrophication over decades, producing variable transparency values among lakes. Macroinvertebrates were sampled from each lake in the rainy and dry seasons, and species richness and abundance were calculated and related to Secchi disc transparency. Cluster analysis showed that community composition was similar in pristine and semitransparent lakes, in contrast with turbid lakes. Considering macroinvertebrate groups, hyalellids were dominant in pristine and semiturbid lakes, whereas chironomids were dominant in turbid lakes. A significant quadratic relationship between richness and Secchi disc depth values was found, which is consistent with the intermediate production hypothesis. This study shows how a gradual change in Secchi disc depth can markedly modify benthic communities.

scholarly journals Efeito do Envelhecimento de Isca na Captura de Moscas (Diptera: Brachycera) em Área de Caatinga

2014 ◽  
Vol 7 (1) ◽  
pp. 01-04 ◽  
Author(s):  
Eduardo Nascimento ◽  
Bianca Ambrogi ◽  
Leandro Sousa Souto ◽  
Marcelo Vilas-Bôas ◽  
Manoel Uchôa
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Exposure Time ◽  
Environmental Changes ◽  
Cane Sugar ◽  
The Other ◽  
Ecological Parameters ◽  
Significant Change ◽  
Species Richness And Abundance

Espécies de Diptera, principalmente as moscas, tem se mostrado como potenciais bioindicadores para mudanças ambientais. Para captura destes animais, há diferentes métodos, incluindo as armadilhas com atrativos alimentares. Neste estudo, para avaliar a eficiência de armadilhas na captura de moscas usando isca de melaço de cana-de-açúcar, foram avaliados os parâmetros ecológicos: abundância, riqueza e composição de espécies de moscas, comparando diferentes períodos de exposição das armadilhas em campo: 24, 48, 72 e 96h. A riqueza e abundância apresentaram mudança significativa em relação ao tempo de exposição da isca, tendo se estabilizado após 48h, e a composição diferiu entre o primeiro dia (24h) e os demais (48, 72, 96h). Effect of Aging Bait for Catching Flies (Diptera: Brachycera) in a Caatinga Area Abstract. Diptera species, especially flies, has shown potential as bioindicators for environmental changes. There are different methods to capture these animals, including traps with food baits. In this study, we assess the efficiency of traps for catching flies using bait of cane sugar molasses, analyzing the ecological parameters: abundance, species richness and species composition of flies during different periods of exposure of the traps in the field: 24, 48, 72 and 96h. Species richness and abundance showed significant change with respect to exposure time in the field, with stabilization after 48h, and species composition differed between the first and the other days.

scholarly journals Spatial Distribution of Lichens in Metrosideros excelsa in Northern New Zealand Urban Forests

Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 170
Author(s):  
Gladys N. Benitez ◽  
Glenn D. Aguilar ◽  
Dan Blanchon
Keyword(s):  
Spatial Distribution ◽  
Species Richness ◽  
New Zealand ◽  
Lichen Species ◽  
Positive Correlation ◽  
Breast Height ◽  
Lichen Community ◽  
The North ◽  
The City ◽  
Lichen Flora

The spatial distribution of corticolous lichens on the iconic New Zealand pōhutukawa (Metrosideros excelsa) tree was investigated from a survey of urban parks and forests across the city of Auckland in the North Island of New Zealand. Lichens were identified from ten randomly selected trees at 20 sampling sites, with 10 sites classified as coastal and another 10 as inland sites. Lichen data were correlated with distance from sea, distance from major roads, distance from native forests, mean tree DBH (diameter at breast height) and the seven-year average of measured NO2 over the area. A total of 33 lichen species were found with coastal sites harboring significantly higher average lichen species per tree as well as higher site species richness. We found mild hotspots in two sites for average lichen species per tree and another two separate sites for species richness, with all hotspots at the coast. A positive correlation between lichen species richness and DBH was found. Sites in coastal locations were more similar to each other in terms of lichen community composition than they were to adjacent inland sites and some species were only found at coastal sites. The average number of lichen species per tree was negatively correlated with distance from the coast, suggesting that the characteristic lichen flora found on pōhutukawa may be reliant on coastal microclimates. There were no correlations with distance from major roads, and a slight positive correlation between NO2 levels and average lichen species per tree.

scholarly journals Spatial distribution patterns of soil total phosphorus influenced by climatic factors in China’s forest ecosystems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jie Zhu ◽  
Anchi Wu ◽  
Guoyi Zhou
Keyword(s):  
Spatial Distribution ◽  
Forest Ecosystems ◽  
Climatic Factors ◽  
Critical Role ◽  
Effect Of Temperature ◽  
P Concentration ◽  
Single Effect ◽  
The Impact ◽  
P Distribution ◽  
Total P

AbstractPhosphorus (P) is an important element in terrestrial ecosystems and plays a critical role in soil quality and ecosystem productivity. Soil total P distributions have undergone large spatial changes as a result of centuries of climate change. It is necessary to study the characteristics of the horizontal and vertical distributions of soil total P and its influencing factors. In particular, the influence of climatic factors on the spatial distribution of soil total P in China’s forest ecosystems remain relatively unknown. Here, we conducted an intensive field investigation in different forest ecosystems in China to assess the effect of climatic factors on soil total P concentration and distribution. The results showed that soil total P concentration significantly decreased with increasing soil depth. The spatial distribution of soil total P increased with increasing latitude and elevation gradient but decreased with increasing longitude gradient. Random forest models and linear regression analyses showed that the explanation rate of bioclimatic factors and their relationship with soil total P concentration gradually decreased with increasing soil depths. Variance partitioning analysis demonstrated that the most important factor affecting soil total P distribution was the combined effect of temperature and precipitation factor, and the single effect of temperature factors had a higher explanation rate compare with the single effect of precipitation factors. This work provides a new farmework for the geographic distribution pattern of soil total P and the impact of climate variability on P distribution in forest ecosystems.

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