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Jéssica Akemi Hitaka Soares - One of the best experts on this subject based on the ideXlab platform.
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Interactive effects between Vegetation Structure and soil fertility on tropical ground-dwelling arthropod assemblages
Applied Soil Ecology, 2020Co-Authors: Luís Fernando De Abreu Pestana, Andréa Lúcia Teixeira De Souza, Marcel O. Tanaka, Facundo M. Labarque, Jéssica Akemi Hitaka SoaresAbstract:Abstract The development of forests undergoing restoration determines the Structure of the Vegetation, influencing ground-dwelling arthropod composition. Soil fertility can interact with Vegetation Structure, influencing the diversity and composition of arthropod assemblages through bottom-up effects on developing forests. We evaluated if soil fertility (here defined by the attributes directly related to macronutrient availability) and the Vegetation Structure in three adjacent areas from different land-use/cover categories (abandoned pasture, riparian forest undergoing restoration, and remnant riparian forest) influences ground-dwelling arthropod assemblages. These areas were subject to a gradient of soil fertility due to the presence of a corral that resulted in a local increase of soil nutrients in the three areas, enabling to evaluate the interaction between soil fertility and Vegetation Structure. We hypothesized that ground-dwelling arthropod assemblages have lower diversity in pasture, intermediate in forest undergoing restoration and higher diversity in the remnant forest. Furthermore, we expected that increasing soil fertility would have a positive effect in these assemblages through bottom-up effects. Environmental conditions were characterized by Vegetation Structure and soil chemical attributes variables, whereas arthropods were sampled with pitfalls and identified to morphospecies. Diversity indicators responded differentially to the studied effects. Abundances decreased with soil fertility, and were higher in the forest undergoing restoration, followed by pasture and remnant forest. Species richness also varied among categories, following the same pattern as abundances. On the other hand, diversity indices indicated an interaction between soil fertility and land use category, with larger effects of soil fertility on diversity in the more simplified habitats (pasture and forest undergoing restoration), whereas no bottom-up effects were recorded in the remnant forest; species evenness increased with soil fertility in all studied areas. A redundancy analysis (RDA) indicated that both Vegetation Structure and soil attributes significantly influenced arthropod composition. Arthropod assemblages in areas undergoing restoration with higher soil fertility and low grass cover were more similar to assemblages in remnant forest when compared to areas with low soil fertility, independently of the Vegetation Structure, indicating an interaction between these two effects. Therefore, ground-dwelling arthropod assemblages responded both to increasing Vegetation complexity resulting from the different land use/cover categories, and to increasing soil fertility, so that they are effective indicators to evaluate the recovery of ecosystems in forest restoration projects and to determine the importance of soil fertility in this process.
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Combined effects of soil fertility and Vegetation Structure on early decomposition of organic matter in a tropical riparian zone
Ecological Engineering, 2020Co-Authors: Jéssica Akemi Hitaka Soares, Luís Fernando De Abreu Pestana, Andréa Lúcia Teixeira De Souza, Marcel O. TanakaAbstract:Abstract Monitoring forests undergoing restoration is important to evaluate not only the development of trees, but also the recovery of ecosystem functions. The decomposition of the organic matter is an important ecological process, and nutrient cycling in ecosystems is a good indicator of forest ecosystem functions because it responds to physical, chemical, and biological characteristics of the Vegetation and the soil. We hypothesized that both soil fertility and Vegetation Structure have direct and positive effects on decomposition processes. We used the Tea Bag Index (Keuskamp et al., 2013) to evaluate early decomposition of the organic matter in three land use categories, pasture, riparian forest undergoing restoration, and riparian forest remnant. Each category extended along a gradient of soil nutrients, enabling to jointly evaluate the effects of soil nutrients and Vegetation Structure on the decomposition process, using structural equations models to also describe the covariance between soil nutrients and Vegetation. The decomposition rates (k) were negatively related to Vegetation development, possibly due to less light in the forest floor, and less activity of the decomposer community. On the other hand, soil fertility had direct positive effects on k, possibly with higher microbial activity due to higher nutrient availability. The stabilization factor (S) was not influenced by soil nutrients or Vegetation Structure. However, in the riparian forest remnant plots, S increased with soil base saturation, indicating an interaction between the effects of soil fertility and land use category. Therefore, the decomposition process in this system responded to soil fertility and Vegetation Structure, but the magnitude of these effects varied with land use. The monitoring of this ecosystem function to evaluate ecosystem recovery should include simultaneously both soil and Vegetation variables.
Angelika Schwabe - One of the best experts on this subject based on the ideXlab platform.
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Multiparameter analysis of vertical Vegetation Structure based on digital image processing
Flora - Morphology Distribution Functional Ecology of Plants, 2003Co-Authors: Andreas Zehm, Michael P. Nobis, Angelika SchwabeAbstract:Summary Changes of vertical arrangements in plant communities cause changes in processes and habitat parameters such as microclimate, nutrient cycles, arthropod behaviour and others. Therefore the description and analysis of structural dynamics is the basis for investigations at the level of processes. With VESTA (VE rtical Vegetation Structure Analysis), an improved photographic method of analysing vertical Vegetation Structure was designed to study various spatial parameters, especially in pione er and grassland ecosystems. Following standardised data sampling in the field based on digital photography, the spatiotemporal characteristics of the vertical Vegetation Structure can be extracted by a newly elaborated software ( SideLook). The new method is introduced, and parameters of analysis such as “denseness” and “roughness” are defined. Evaluation of the method gives these main results : – multiple structural characteristics of vertical Vegetation Structure can be obtained on the basis of digital images, – the method is quick and easy to apply in nearly all weather situations, – the data output is robust against differences between persons using the method, – the effects of optical distortions are slight, and height and other parameters are robust in a comparison to field data, – a good correlation with above-ground phytomass coverage was found, and – the data output can easily be used for subsequent data analysis, e.g. by ordination techniques.
Marcel O. Tanaka - One of the best experts on this subject based on the ideXlab platform.
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Interactive effects between Vegetation Structure and soil fertility on tropical ground-dwelling arthropod assemblages
Applied Soil Ecology, 2020Co-Authors: Luís Fernando De Abreu Pestana, Andréa Lúcia Teixeira De Souza, Marcel O. Tanaka, Facundo M. Labarque, Jéssica Akemi Hitaka SoaresAbstract:Abstract The development of forests undergoing restoration determines the Structure of the Vegetation, influencing ground-dwelling arthropod composition. Soil fertility can interact with Vegetation Structure, influencing the diversity and composition of arthropod assemblages through bottom-up effects on developing forests. We evaluated if soil fertility (here defined by the attributes directly related to macronutrient availability) and the Vegetation Structure in three adjacent areas from different land-use/cover categories (abandoned pasture, riparian forest undergoing restoration, and remnant riparian forest) influences ground-dwelling arthropod assemblages. These areas were subject to a gradient of soil fertility due to the presence of a corral that resulted in a local increase of soil nutrients in the three areas, enabling to evaluate the interaction between soil fertility and Vegetation Structure. We hypothesized that ground-dwelling arthropod assemblages have lower diversity in pasture, intermediate in forest undergoing restoration and higher diversity in the remnant forest. Furthermore, we expected that increasing soil fertility would have a positive effect in these assemblages through bottom-up effects. Environmental conditions were characterized by Vegetation Structure and soil chemical attributes variables, whereas arthropods were sampled with pitfalls and identified to morphospecies. Diversity indicators responded differentially to the studied effects. Abundances decreased with soil fertility, and were higher in the forest undergoing restoration, followed by pasture and remnant forest. Species richness also varied among categories, following the same pattern as abundances. On the other hand, diversity indices indicated an interaction between soil fertility and land use category, with larger effects of soil fertility on diversity in the more simplified habitats (pasture and forest undergoing restoration), whereas no bottom-up effects were recorded in the remnant forest; species evenness increased with soil fertility in all studied areas. A redundancy analysis (RDA) indicated that both Vegetation Structure and soil attributes significantly influenced arthropod composition. Arthropod assemblages in areas undergoing restoration with higher soil fertility and low grass cover were more similar to assemblages in remnant forest when compared to areas with low soil fertility, independently of the Vegetation Structure, indicating an interaction between these two effects. Therefore, ground-dwelling arthropod assemblages responded both to increasing Vegetation complexity resulting from the different land use/cover categories, and to increasing soil fertility, so that they are effective indicators to evaluate the recovery of ecosystems in forest restoration projects and to determine the importance of soil fertility in this process.
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Combined effects of soil fertility and Vegetation Structure on early decomposition of organic matter in a tropical riparian zone
Ecological Engineering, 2020Co-Authors: Jéssica Akemi Hitaka Soares, Luís Fernando De Abreu Pestana, Andréa Lúcia Teixeira De Souza, Marcel O. TanakaAbstract:Abstract Monitoring forests undergoing restoration is important to evaluate not only the development of trees, but also the recovery of ecosystem functions. The decomposition of the organic matter is an important ecological process, and nutrient cycling in ecosystems is a good indicator of forest ecosystem functions because it responds to physical, chemical, and biological characteristics of the Vegetation and the soil. We hypothesized that both soil fertility and Vegetation Structure have direct and positive effects on decomposition processes. We used the Tea Bag Index (Keuskamp et al., 2013) to evaluate early decomposition of the organic matter in three land use categories, pasture, riparian forest undergoing restoration, and riparian forest remnant. Each category extended along a gradient of soil nutrients, enabling to jointly evaluate the effects of soil nutrients and Vegetation Structure on the decomposition process, using structural equations models to also describe the covariance between soil nutrients and Vegetation. The decomposition rates (k) were negatively related to Vegetation development, possibly due to less light in the forest floor, and less activity of the decomposer community. On the other hand, soil fertility had direct positive effects on k, possibly with higher microbial activity due to higher nutrient availability. The stabilization factor (S) was not influenced by soil nutrients or Vegetation Structure. However, in the riparian forest remnant plots, S increased with soil base saturation, indicating an interaction between the effects of soil fertility and land use category. Therefore, the decomposition process in this system responded to soil fertility and Vegetation Structure, but the magnitude of these effects varied with land use. The monitoring of this ecosystem function to evaluate ecosystem recovery should include simultaneously both soil and Vegetation variables.
Luís Fernando De Abreu Pestana - One of the best experts on this subject based on the ideXlab platform.
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Interactive effects between Vegetation Structure and soil fertility on tropical ground-dwelling arthropod assemblages
Applied Soil Ecology, 2020Co-Authors: Luís Fernando De Abreu Pestana, Andréa Lúcia Teixeira De Souza, Marcel O. Tanaka, Facundo M. Labarque, Jéssica Akemi Hitaka SoaresAbstract:Abstract The development of forests undergoing restoration determines the Structure of the Vegetation, influencing ground-dwelling arthropod composition. Soil fertility can interact with Vegetation Structure, influencing the diversity and composition of arthropod assemblages through bottom-up effects on developing forests. We evaluated if soil fertility (here defined by the attributes directly related to macronutrient availability) and the Vegetation Structure in three adjacent areas from different land-use/cover categories (abandoned pasture, riparian forest undergoing restoration, and remnant riparian forest) influences ground-dwelling arthropod assemblages. These areas were subject to a gradient of soil fertility due to the presence of a corral that resulted in a local increase of soil nutrients in the three areas, enabling to evaluate the interaction between soil fertility and Vegetation Structure. We hypothesized that ground-dwelling arthropod assemblages have lower diversity in pasture, intermediate in forest undergoing restoration and higher diversity in the remnant forest. Furthermore, we expected that increasing soil fertility would have a positive effect in these assemblages through bottom-up effects. Environmental conditions were characterized by Vegetation Structure and soil chemical attributes variables, whereas arthropods were sampled with pitfalls and identified to morphospecies. Diversity indicators responded differentially to the studied effects. Abundances decreased with soil fertility, and were higher in the forest undergoing restoration, followed by pasture and remnant forest. Species richness also varied among categories, following the same pattern as abundances. On the other hand, diversity indices indicated an interaction between soil fertility and land use category, with larger effects of soil fertility on diversity in the more simplified habitats (pasture and forest undergoing restoration), whereas no bottom-up effects were recorded in the remnant forest; species evenness increased with soil fertility in all studied areas. A redundancy analysis (RDA) indicated that both Vegetation Structure and soil attributes significantly influenced arthropod composition. Arthropod assemblages in areas undergoing restoration with higher soil fertility and low grass cover were more similar to assemblages in remnant forest when compared to areas with low soil fertility, independently of the Vegetation Structure, indicating an interaction between these two effects. Therefore, ground-dwelling arthropod assemblages responded both to increasing Vegetation complexity resulting from the different land use/cover categories, and to increasing soil fertility, so that they are effective indicators to evaluate the recovery of ecosystems in forest restoration projects and to determine the importance of soil fertility in this process.
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Combined effects of soil fertility and Vegetation Structure on early decomposition of organic matter in a tropical riparian zone
Ecological Engineering, 2020Co-Authors: Jéssica Akemi Hitaka Soares, Luís Fernando De Abreu Pestana, Andréa Lúcia Teixeira De Souza, Marcel O. TanakaAbstract:Abstract Monitoring forests undergoing restoration is important to evaluate not only the development of trees, but also the recovery of ecosystem functions. The decomposition of the organic matter is an important ecological process, and nutrient cycling in ecosystems is a good indicator of forest ecosystem functions because it responds to physical, chemical, and biological characteristics of the Vegetation and the soil. We hypothesized that both soil fertility and Vegetation Structure have direct and positive effects on decomposition processes. We used the Tea Bag Index (Keuskamp et al., 2013) to evaluate early decomposition of the organic matter in three land use categories, pasture, riparian forest undergoing restoration, and riparian forest remnant. Each category extended along a gradient of soil nutrients, enabling to jointly evaluate the effects of soil nutrients and Vegetation Structure on the decomposition process, using structural equations models to also describe the covariance between soil nutrients and Vegetation. The decomposition rates (k) were negatively related to Vegetation development, possibly due to less light in the forest floor, and less activity of the decomposer community. On the other hand, soil fertility had direct positive effects on k, possibly with higher microbial activity due to higher nutrient availability. The stabilization factor (S) was not influenced by soil nutrients or Vegetation Structure. However, in the riparian forest remnant plots, S increased with soil base saturation, indicating an interaction between the effects of soil fertility and land use category. Therefore, the decomposition process in this system responded to soil fertility and Vegetation Structure, but the magnitude of these effects varied with land use. The monitoring of this ecosystem function to evaluate ecosystem recovery should include simultaneously both soil and Vegetation variables.
Gregory P. Asner - One of the best experts on this subject based on the ideXlab platform.
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Effects of Vegetation Structure on the Location of Lion Kill Sites in African Thicket
PloS one, 2016Co-Authors: Andrew B. Davies, Craig J. Tambling, Graham I. H. Kerley, Gregory P. AsnerAbstract:Predator-prey relationships are integral to ecosystem stability and functioning. These relationships are, however, difficult to maintain in protected areas where large predators are increasingly being reintroduced and confined. Where predators make kills has a profound influence on their role in ecosystems, but the relative importance of environmental variables in determining kill sites, and how these might vary across ecosystems is poorly known. We investigated kill sites for lions in South Africa’s thicket biome, testing the importance of Vegetation Structure for kill site locations compared to other environmental variables. Kill sites were located over four years using GPS telemetry and compared to non-kill sites that had been occupied by lions, as well as to random sites within lion ranges. Measurements of 3D Vegetation Structure obtained from Light Detection and Ranging (LiDAR) were used to calculate the visible area (viewshed) around each site and, along with wind and moonlight data, used to compare kill sites between lion sexes, prey species and prey sexes. Viewshed area was the most important predictor of kill sites (sites in dense Vegetation were twice as likely to be kill sites compared to open areas), followed by wind speed and, less so, moonlight. Kill sites for different prey species varied with Vegetation Structure, and male prey were killed when wind speeds were higher compared to female prey of the same species. Our results demonstrate that Vegetation Structure is an important component of predator-prey interactions, with varying effects across ecosystems. Such differences require consideration in terms of the ecological roles performed by predators, and in predator and prey conservation.
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Lion hunting behaviour and Vegetation Structure in an African savanna
Animal Behaviour, 2013Co-Authors: Scott R. Loarie, Craig J. Tambling, Gregory P. AsnerAbstract:Emerging evidence suggests that male lions are not dependent on female's hunting skills but are in fact successful hunters. But difficulty locating kills and objectively characterizing landscapes has complicated the comparison of male and female lion hunting strategies. We used airborne Light Detection and Ranging (LiDAR) measurements of Vegetation Structure in Kruger National Park, combined with global positioning system (GPS) telemetry data on lion, Panthera leo, kills to quantify lines-of-sight where lion kills occurred compared with areas where lions rested, while controlling for time of day. We found significant differences in use of Vegetation Structure by male and female lions during hunts. While male lions killed in landscapes with much shorter lines-of-sight (16.2 m) than those in which they rested, there were no significant differences for female lions. These results were consistent across sizes of prey species. The influence of Vegetation Structure in shaping predator–prey interactions is often hypothesized, but quantitative evidence has been scarce. Although our sample sizes were limited, our results provide a mechanism, ambush hunting versus social hunting in the open, to explain why hunting success of male lions might equal that of females. This study serves as a case study for more complete studies with larger samples sizes and illustrates how LiDAR and GPS telemetry can be used to provide new insight into lion hunting behaviour.
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Effects of fire on woody Vegetation Structure in African savanna
Ecological applications : a publication of the Ecological Society of America, 2010Co-Authors: Izak P.j. Smit, Gregory P. Asner, Navashni Govender, Ty Kennedy-bowdoin, David E. Knapp, James JacobsonAbstract:Despite the importance of fire in shaping savannas, it remains poorly understood how the frequency, seasonality, and intensity of fire interact to influence woody Vegetation Structure, which is a key determinant of savanna biodiversity. We provide a comprehensive analysis of vertical and horizontal woody Vegetation Structure across one of the oldest savanna fire experiments, using new airborne Light Detection and Ranging (LiDAR) technology. We developed and compared high-resolution woody Vegetation height surfaces for a series of large experimental burn plots in the Kruger National Park, South Africa. These 7-ha plots (total area ~ 1500 ha) have been subjected to fire in different seasons and at different frequencies, as well as no-burn areas, for 54 years. Long-term exposure to fire caused a reduction in woody Vegetation up to the 5.0-7.5 m height class, although most reduction was observed up to 4 m. Average fire intensity was positively correlated with changes in woody Vegetation Structure. More frequent fires reduced woody Vegetation cover more than less frequent fires, and dry-season fires reduced woody Vegetation more than wet season fires. Spring fires from the late dry season reduced woody Vegetation cover the most, and summer fires from the wet season reduced it the least. Fire had a large effect on Structure in the densely wooded granitic landscapes as compared to the more open basaltic landscapes, although proportionally, the woody Vegetation was more reduced in the drier than in the wetter landscapes. We show that fire frequency and fire season influence patterns of Vegetation three-dimensional Structure, which may have cascading consequences for biodiversity. Managers of savannas can therefore use fire frequency and season in concert to achieve specific Vegetation structural objectives.
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The relative influence of fire and herbivory on savanna three-dimensional Vegetation Structure.
Biological Conservation, 2009Co-Authors: Shaun R. Levick, Gregory P. Asner, Ty Kennedy-bowdoin, David E. KnappAbstract:Abstract The relative importance of fire and herbivory on Vegetation Structure has been the subject of much debate in savanna ecology. Fire regime and herbivore numbers are two key variables that managers of protected areas can manipulate to meet their conservation objectives. We deployed a new airborne remote sensing system (Carnegie Airborne Observatory) to the Kruger National Park (KNP), South Africa, to map a unique herbivore/fire exclusion experiment on basaltic soils. We collected high resolution (56 cm) three-dimensional (3-D) Vegetation structural data over areas that have been protected from herbivores (34 yr) and/or fire (7 yr), as well as those exposed to both disturbance agents. Canopy height distribution, as well as the distribution of foliage within the vertical canopy profile, differed significantly between all treatments and between each treatment and the control area (Kolmogorov–Smirnov, p 9 m) and up to 66 times more small tree canopy (3–6 m). Fire restricted growth of Vegetation in the 0–3 m height range, both in the absence and presence of herbivores. Our findings highlight the active role that conservation managers can play in modifying Vegetation Structure and heterogeneity through herbivore and fire management, as well as the value of 3-D remote sensing for the assessment of conservation management outcomes.
