Search Results (6)

Urbanization replaces natural vegetation for city expansion, impacting environmental and climatic variables that affect the health of the human population and fauna. These changes affect important groups such as birds, given their greater sensitivity to anthropogenic alterations, especially when we understand these effects on a large scale, considering countries such as Brazil, which represents the third country with the greatest diversity of bird species in the world. Conversely, green spaces like urban parks, tree-lined avenues, and riparian forests seem to foster biodiversity conservation. Here, we analyze the effects of vegetation on bird communities and bird–plant interactions in urban riparian areas that have undergone ecological restoration. The study was carried out between January and October 2019 in two restored urban areas of Uberlândia, Brazil. Results showed that the richness of birds observed between the two areas was Praia Clube (n = 86) and Parque Linear Rio Uberabinha (n = 80). The most representative trophic guilds in the areas, with the highest proportion in their relative abundances during both seasons, were granivores, omnivores, insectivores, and frugivores. Composition varied significantly between areas as a function of the plant community, particularly when considering the interaction between season and area (ANOSIM: R = 0.19; Stress = 0.10; p = 0.008). In environments dominated by generalist and synanthropic species (Eared Dove, Picazuro Pigeon), effective planning and management of green areas are crucial. It is important to acknowledge that certain bird species depend on specific habitats, such as riparian forests, and that specific plant species within these areas are vital for specialized bird species, such as species endemic to the Brazilian Savanna or Cerrado and restricted to Brazil (White-striped Warbler) and species in vulnerable categories globally (Bare-faced Curassow). Therefore, restoration efforts in degraded areas should be carefully planned to restore interactions and conserve biodiversity effectively. Full article

Island ecology plays an important role in explaining various ecological and evolutionary processes. Small, isolated oceanic islands, exemplified by the Azores Archipelago, are especially vulnerable to adverse environmental conditions and human impact. The study aims to evaluate the impact of urbanization, especially the urban greening space, on the structure and dynamics of avian communities associated with various landforms in an urbanized landscape in one of the nine islands of the Azores Archipelago, São Miguel Island, in the northeast Atlantic Ocean. Samples were collected in the second half of April 2024. The line transect method (43 transects with a total of 37.4 km) was employed to count all bird species breeding in different landforms distinguished in the city: coastal land, urbanized land, rural land, and urban greening space. The obtained results showed that the number of breeding species was much higher in urban greening spaces (n = 20) than in the other lands (n = 10–14 species). Both cumulative dominance and dominance indices were much lower in urban greening space than in the other landforms. The Sørensen Index of Similarity between the four main land categories distinguished in the city varied between 0.62 and 0.96, being the lowest between the coastal and urban greening space, and the highest between the urbanized and rural lands. Two main feeding guilds were distinguished in the study area: granivores and insectivores. The former guild clearly dominated over the latter in all major land categories distinguished. Clearly, the proportion of granivores increased with urbanization. Also, two nesting guilds were distinguished: buildings and trees/shrubs. The former was dominant in all land categories except for the urban greening space where the tree/shrub nesting guild was more numerous than the building guild. The tree/shrub guild declined with urbanization. A general trend was recorded: the higher the level of urbanization, the lower the percentage of urban greening space, and in consequence, the lower the number of bird species and diversity indices, but the higher the cumulative dominance and dominance indices. The overall density of birds remains, however, distinctively similar. In the future, data on the population densities and dominance of particular species should be collected in urbanized landforms in other towns of the Azores Archipelago and Macaronesia at large. Full article

Forest canopies, an essential part of forest ecosystems, are among the most highly threatened terrestrial habitats. Mountains provide ideal conditions for studying the variation in community structure with elevations. Spiders are one of the most abundant predators of arthropods in terrestrial ecosystems and can have extremely important collective effects on forest ecosystems. How the diversity and composition of canopy spider communities respond to elevation changes in temperate forests remains poorly understood. In this study, we collected canopy spiders from four elevation sites (800 m, 1100 m, 1400 m, and 1700 m) on Changbai Mountain using the fogging method in August 2016. With the methods of ANOVA analysis, transformation-based redundancy analysis, and random forest analysis, we explored the responses of canopy spider communities to elevation. In total, 8826 spiders comprising 81 species were identified and the most abundant families were Thomisidae, Clubionidae, Linyphiidae, and Theridiidae (77.29% of total individuals). Species richness decreased whereas evenness increased with increasing elevation, indicating that elevation has an important impact on community structure. The pattern of absolute abundance was hump shaped with increasing elevation. We found that the community compositions at the three taxonomic levels (species, family, and guild) along the elevation gradient were obviously altered and the variation in community composition was higher at low-elevation sites than at high-elevation sites. There were 19 common species (23.46%) among the four elevations. Regression and RDA results showed that vegetation variables contributed to the variation in the diversity and composition of canopy spiders. Furthermore, the influence of factors would be weakened with the taxonomic level increasing. Therefore, our findings greatly highlight the important role of vegetation in the diversity and composition of canopy spiders and the influence is closely related to the taxonomic level. Full article

The frequency and intensity of hurricanes have increased with climate change, and their effects on most taxa are not known. We analyzed a species diversity of bats in three locations with different regimes of anthropic disturbance. We assessed the effect of the season and post-hurricane time on the abundance of trophic guilds in coastal Jalisco, México, during the two years following Hurricane Patricia (category 4). During a sampling effort of 15,629.76 m² of netting, we captured 790 bats of 21 species. The species diversity was higher in the site with the highest proportion of primary tropical deciduous forest and was higher in 2016 than in 2017; the species composition did not differ greatly between the two years. The abundance of bats in various trophic guilds varied relative to the four climatic seasons. The general abundance of bats, frugivores-omnivores, and insectivores showed a significant increasing trend over time after the hurricane, which may indicate a recovery of the ecosystem or an abundance of early-successional fruiting plants. The results also confirm that species diversity recovers faster in a conserved forest. Thus, it is important to conserve natural areas to mitigate the effects of major disturbances. Full article

Percent soil organic matter (SOM), pH and crop yield are among the biophysicochemical process-driven soil health indicators (SHIs). However, identifying sustainable soil health conditions using these SHIs is limited due to the lack of Integrated Productivity Efficiency (IPE) models. We define IPE as a concept that identifies best-to-worst-case soil health outcomes by assessing the effect of agronomic practices on weighted abundance of functional guilds (WAFG) of beneficial soil organisms and SHIs simultaneously. Expressing WAFG of all beneficial nematodes (x-axis) and SHIs (y-axis) as a percent of untreated control and regression of x and y reveals four quadrants describing worst-to-best-case outcomes for soil health and sustainability. We tested the effects of composted cow manure (AC) and plant litter (PC) applied at 135 (1×), 203 (1.5×), and 270 (2×) kg N/ha on WAFG, SOM, pH, and yield in a sandy clay loam field of a processing carrot cultivar over three growing seasons. Untreated control and urea at 1× served as experimental controls. Data that varied by time and were difficult to make sense of were separated into sustainable, unsustainable, or requiring specific modification to be sustainable categories by the IPE model. Within the sustainable category, all AC treatments and 2× rate of PC treatments had the best integrated efficiency outcomes across the SHIs. The IPE model provides a platform where other biophysicochemical process-driven SHIs could be integrated. Full article

Understanding energy flow and nutrient pathways is crucial to reveal the dynamics and functions of riverine ecosystems and develop appropriate conservation strategies. In this study, we utilized stable isotopes of δ¹³C and δ¹⁵N to examine the fundamental characteristics of trophic position, trophic niche, and carbon source for the food web in the midstream of the Chishui River, a tributary to the Yangtze River. Our results showed that stable isotope signatures among different sorts of basal resources and consumers were significantly distinguishable and that the food chain consisted of four trophic levels, indicating the multiple trophic pathways and long food chain length here. The trophic guilds of fish were classified into four categories, in which herbivorous and carnivorous fish showed greater trophic diversity and omnivorous fish had higher trophic redundancy, which meant that there was a stable trophic niche structure in the study area. Phytoplankton and periphyton presented the largest contributions to consumers, indicating that autochthonous productivity was the dominant carbon source in the midstream of the Chishui River. Since the Chishui River is still in a natural condition without any dam constructions, the autochthonous productivity, stable trophic niche structure, multiple trophic pathways and long food chain length found here demonstrate its high conservation value. Therefore, the strategy to refrain from damming on this river should persist into the future. Full article