Analysis of primary productivity of robinia pseudoacacia plantations on reclaimed lands of steppe Pridneprovye

Ecological application of wavelet analysis in the scaling of spatial distribution patterns of Ceratoides ewersmanniana

Understanding the forces that influence the distribution of land use and land-use change (LUC) is an essential step in developing effective strategies for managing these issues. We examined the influence of landscape position on spatial patterns in land-use distribution within the Little Tennessee River Basin (LTRB) of the southern Appalachian Mountains. We show that landscape position, defined with respect to both natural and anthropogenic spatial variables, provides for the identification of statistically significant differences in the distribution of common forms of land use in the study region. Using the same variables, significant differences in the landscape positions subject to land-use change in the LTRB are also examined. These results suggest landscape position exerts a strong influence on the distribution of different forms of land use and the likeliness of given area undergoing LUC. The approach presented here, of considering land use as a function of landscape position that responds to both natural and anthropogenic forces, may prove useful in aiding the development of future strategies to address the consequences of land use in many regions.

ABSTRACTQuestionsAccurately measuring species distribution patterns has long been a fundamental task in community and spatial ecology. This study tries to address the following ecological problems: (1) Are distance‐based methods powerful and sensitive enough to detect subtle changes of spatial distributional patterns of species in a distributional map, particularly when it comes to complete random distribution? (2) How can spatial distributional aggregation patterns be effectively and rapidly compared when the size of spatial distributional data is large?LocationGlobal.MethodsWe propose a one‐dimensional aggregation index, quadrat nearest neighboring distance (QNN), integrated with an optimal spatial subdivision protocol. This method was evaluated via numerical simulations and applied to empirical species distribution data and compared against Clark and Evans' R index, which is built upon two‐dimensional nearest neighboring distance (NND).ResultsQNN is accurate in detecting complete random distribution over different population sizes of species. The accuracy of QNN depended on using an optimal gridding size. The accuracy of detecting the complete random distribution of species is guaranteed when the sampling grain size in QNN is around the optimal gridding size. Furthermore, QNN showed high computational efficiency in extensive numerical simulations.ConclusionsQNN offers a powerful, efficient, and scalable tool for detecting and comparing species spatial distribution patterns. Its enhanced sensitivity to random distributions and dependence on optimal gridding make it especially suitable for analyzing large‐scale or high‐resolution spatial data.

Spatial and temporal evolution of drought characteristics across the Yellow River basin

Spatial Distribution of Chironomid Larvae (Diptera) on Leaves of the Bulrush in a Chalk Stream

Intertidal rocky shores represent an extremely stressful physical environment dictated by the rise and fall of the tides. One of the major environmental stresses over this gradient is temperature, especially towards the upper reaches of the shore where species spend long periods out of water exposed to hot, desiccating conditions. As a result, the thermal tolerance of intertidal species is often positively correlated with their vertical distributions, and the physiological and molecular limits that drive such patterns have been the subject of recent research. Understanding these tolerance limits, from small (e.g. vertical distribution) to large (e.g. latitudinal) spatial scales, may provide information to predict species’ success under future climate change scenarios, and thus possible changes in community structure.\n\n\n\nGiven their abundance in the high shore, and well resolved taxonomy and phylogeography, the littorinids Echinolittorina malaccana, E. radiata and E. vidua are excellent models to investigate the relationship between thermal tolerance and spatial distribution patterns. These littorinids are widely distributed on Hong Kong shores and exhibit a distinct and consistent vertical distribution that ranges from temperate to tropical regions along the western Pacific coast. Field surveys in summer and winter at two moderately exposed shores (Stanley and South Bay, Hong Kong) showed that E. malaccana was distributed highest on the shore, followed by E. radiata and E. vidua respectively, and all the three species were found ~ 0.25m lower on the shore in summer than winter. Laboratory experiments, including determination of survival limits (LT50), Arrhenius breakpoint temperature of heart rate (ABT of HR) and activities of metabolic enzymes (MDH and LDH), were used to establish if the physiological attributes of the three species were related to their distribution patterns. The LT50 of E. malaccana were the highest of the three species (56.47oC), followed by E. radiata (55.5oC), and finally the lower shore species E. vidua (53.7oC); while ABT of HR in E. malaccana (48.2oC) was also higher than E. radiata (46.5oC) and E. vidua (46.6oC). The enzyme activities did not show any clear patterns. In terms of seasonal variation, LT50 and ABT of HR of all three Echinolittorina species were higher in summer than winter, which showed the potential for the littorinids to acclimate when environmental conditions become more severe.\n\n\n\nThe present study provided a fundamental understanding of how physiological, temperature tolerance may determine the spatial and temporal distribution patterns of Echinolittorina species at a local scale where strong environmental gradients vary vertically and also between seasons. Information on the tolerance limits of physiological traits such as LT50, heart rates and enzyme functioning may direct further investigations to identify the underlying causes of the survival limits of these species to temperature variation, and whether this tolerance is genetically or environmentally determined, for example through acclimation. Such studies will provide insights into how a species' physiology may limit their present-day distributions at multiple scales from local to biogeographical, but also enable predictions of how species may respond to changing temperature regimes.

The aim of this study was to identify the spatial pattern of biomass distribution in the revegetation of the post-mining area in PTVI. The nearest neighbour analysis method by comparing the distance of an individual was used to determine the spatial biomass distribution pattern in the post nickel mining revegetation area of PTVI. The nearest neighbour analysis was used to explain the distribution pattern of locations using a calculation that considers the distance, number of locations and acreage. This analysis produced a final result in the form of an index ranging from 0 until more than 1. It can be explained as NNI <1, clustered spatial pattern, NNI = 1, random spatial pattern and NNI> 1 dispersed spatial pattern. This research was found that there are clustered (K1, K2, K3) and dispersed patterns (K4) of biomass spatial distribution patterns in PTVI’s post nickel mining revegetation area.Keywords: post-mining, revegetation, biomass, spatial distribution pattern

Some moths species are considered good indicators of habitat quality because they are very responsive to human disturbance, vegetation type, and successional processes. However, Saturniidae moths have not yet been considered as indicators of environmental quality. Little is known on the distribution of moth species in different vegetation types and the moths’ seasonal variations in the Brazilian savannah. Therefore, this study aims to describe the spatial distribution and temporal patterns of moths belonging to the Saturniidae family in two vegetation types—Cerrado sensu stricto on rocky outcrops and semi-deciduous forest—in both the rainy and dry seasons. It addresses the influence of the climatic seasons and vegetation types on abundance, richness, and species composition to describe the temporal and spatial distribution patterns and the relationship between the ecological aspects and the life history of these moths. This study was conducted in the Cerrado phytogeographical domain, in Pireneus State Park, Goias, Brazil. The results revealed that most Saturniidae species sampled are present during the rainy season and typically found in forest habitats. Furthermore, a clear positive connection was found between the abundance pattern and rainfall seasonality and humid habitats; this is apparently related to the physiological tolerance of these moths, due to rudimentary mouthparts during their adulthood. Thus, rainfall and a forest habitat are important to and fundamental requirements for the persistence of the Saturniidae species in the Cerrado domain. Based on the results of this study, we suggest the use of saturniid species as indicators of changes in vegetation and climatic conditions.

(1) Background: Mammographic breast density (MBD) and older age are classical breast cancer risk factors. Normally, MBDs are not evenly distributed in the breast, with different women having different spatial distribution and clustering patterns. The presence of MBDs makes tumors and other lesions challenging to be identified in mammograms. The objectives of this study were: (i) to quantify the amount of MBDs—in the whole (overall), different sub-regions, and different zones of the breast using an image segmentation method; (ii) to investigate the spatial distribution patterns of MBD in different sub-regions of the breast. (2) Methods: The image segmentation method was used to quantify the overall amount of MBDs in the whole breast (overall percentage density (PD)), in 48 sub-regions (regional PDs), and three different zones (zonal PDs) of the whole breast, and the results of the amount of MBDs in 48 sub-regional PDs were further analyzed to determine its spatial distribution pattern in the breast using Moran’s I values (spatial autocorrelation). (3) Results: The overall PD showed a negative correlation with age (p = 0.008); the younger women tended to have denser breasts (higher overall PD in breasts). We also found a higher proportion (p < 0.001) of positive autocorrelation pattern in the less dense breast group than in the denser breast group, suggesting that MBDs in the less dense breasts tend to be clustered together. Moreover, we also observed that MBDs in the mature women (<65 years old) tended to be clustered in the middle zone, while in older women (>64 years old) they tended to be clustered in both the posterior and middle zones. (4) Conclusions: There is an inverse relationship between the amount of MBD (overall PD in the breast) and age, and a different clustering pattern of MBDs between the older and mature women.

The Sumatran elephant is currently classified as critically endangered. A variety of conservation and conflict management initiatives have been implemented with the objective of reducing the intensity of conflict between elephants and humans. The use of GPS collars for monitoring purposes not only serves to reduce conflict but also allows for the continuous monitoring of Sumatran elephant movements. This study aims to analyze the spatial distribution and movement patterns of Sumatran elephants in GSK Elephant Pockets based on habitat factors, namely land cover class, slope, distance from rivers, and distance from roads. The research was conducted between December 2023 to June 2024 GSK Elephant Enclave, Riau. This study employed a multi-source approach to obtain data on the movement patterns of Sumatran elephants. These included data from the Sumatran Elephant GPS Collar, which recorded the animals' movements between 2021-2023. The movement characteristics analyzed include the length of the path traversed by the Sumatran elephant, Nearest neighbor classification was employed for the analysis of spatial distribution patterns. The result showed that spatial distribution pattern of Sumatran elephants in GSK Elephant Pockets 2021-2023 is clustered with an NNI of 0.47 (NNI &lt; 1). The highest number of Sumatran elephant movements in 2023 based on habitat factors, namely land cover class, was in plantation forest, with 4,788 movements (82.23%). The next highest number of movements was in flat slope class, with 3,229 movements (55.45%). The distance from the river was 0–500 m, with 2,323 movements (39.89%), while the distance from the road was 0–500 m, with 5,390 movements (92.56%).

The Sainte Marie Channel on the northeast coast of Madagascar is an important breeding ground for humpback whales; the first observation of birth was documented there, yet it has never been investigated for phenology and habitat use of humpback whales. The present study was aimed at examining temporal and spatial distribution patterns and the encounter rate of different social groups of humpback whales during the breeding season. We used a large set of opportunistic sightings data collected from whale-watching boats. A total of 3 247 sightings were collected during 897 whale-watching trips conducted between June and September from 2009 to 2013. Our study complements previous information on the seasonal presence of humpback whale social groups by demonstrating a persistent and well-structured temporal pattern in the succession of the different groups. Over the different years of the study period, groups without calves consistently dominated the first 30 days of the breeding season, followed by an increase in groups with calves. Interannual differences were observed in the encounter rates, with significantly higher global encounter rates in 2009, 2011 and 2013 (2.2, 2.3 and 2.3 sightings h–1, respectively), and likewise for the mean encounter rates for groups with calves. In contrast, the encounter rate of groups without calves was similar over the study period. Although our study area exhibits a narrow configuration and poorly contrasting physiographic features due to its restricted spatial extent, we report a spatially segregated pattern of humpback whale social groups in the Sainte Marie Channel. A general linear model showed that groups with calves were influenced by water depth and distance from shore, being observed mostly in shallow waters (to 20 m depth) and close to the coastline (6 km). Our findings will be useful for the development of strategic sustained management plans by providing baseline information on humpback whale distribution at an important but poorly documented breeding site.

Dominant species of macrobenthos were analyzed based on differentiation of three distinct methods: the density based method, the biomass based method and LeBris method, by considering the frequency of occurrence using quantitative data collected over 5 years (1993-1998) at 21 stations in Chonsu Bay. Sedimentary environments as well as species composition and diversity showed the spatial and temporal distribution patterns. The ranks of dominant species as determined by the density based method were more similar to the results by the LeBris method than to those from the biomass based method. Considering the temporal variation, LeBris method were more efficient than any other methods for the determination of dominant species in Chonsu Bay. Lumbrineris longifolia, Theora fragilis, and Moerella jedoensis were recognized by all three methods. A one-way analysis of variance indicated spatial distributions patterns among most of the dominant species. These species showed positive correlations to sedimentary parameters such as mean grain size. However, T. fragilis and Paraprinospio pinnata showed the temporal patterns in their distribution, and were also correlated to the benthic environment, organic content and dissolved oxygen. Some dominant species, e.g., T. fragilis, S. scutata, G. gurjanovae proved to be useful benthic indicators based on the environmental variations determinated by long-term benthic ecological monitoring in Chonsu Bay.

Protein content, a vital component determining the nutritional quality of oysters, is unevenly distributed in different parts of oyster. In this study, the spatial distribution (visceral mass, mantle, gill, and adductor) patterns and structural characteristics of proteins, including water–soluble proteins (WSP), salt–soluble proteins (SSP), acid–soluble proteins (ASP) and alkali–soluble proteins (ALSP) of oysters (Crassostrea hongkongensis) were investigated with the amino acid analyzer, circular dichroism spectroscopy (CD), fourier transform infrared spectroscopy (FTIR), and fluorescence spectroscopy. The results showed that oyster proteins were mainly distributed in the visceral mass and mantle. The protein composition was WSP, SSP, ALSP, and ASP in descending order, which conformed to the ideal amino acid pattern. Variations in secondary structure, molecular weight distribution, and thermal denaturation temperatures of the oyster proteins were observed. SSP had wider bands (16–270 kDa) than those of ASP (30–37 kDa) and ALSP (66–270 kDa). Among the four proteins, the SSP of the mantle showed the highest thermal stability (87.4 °C), while ALSP of the adductor muscle had the lowest the lowest the peak denaturation temperature (Tm) (53.8 °C). The proportions of secondary structures in oyster proteins were different, with a higher proportion of solid protein β–folds, and the exposure of aromatic amino acid residues and disulfide bonds and the microenvironment in which they were located were also different.

The hydrological situations of wetlands are critical to the habitat qualities of wintering migratory birds. It is of great value to evaluate the habitat vulnerabilities within more precise intervals of water levels and quantitatively assess the influences of water level changes. The findings are advantageous for managing wetland ecosystems and for migratory bird habitat protection. This study identified the ideal habitats for wintering Siberian cranes in Poyang Lake wetland within 1-meter water level intervals (from 5 to 16 m) based on the Landsat thematic mapper (TM), enhanced thematic mapper plus (ETM+), and operational land imager (OLI) remote sensing images taken on multiple dates in the past 30 years. Three indicators—sustainability, stability, and variety—were used to evaluate the vulnerabilities of crane habitats within various water level intervals; the spatial variations and distribution patterns of the habitat vulnerabilities were further explored. The explanatory powers of water level intervals (and others) and their paired interactive effects on the habitat vulnerabilities were quantified using the geographical detector method. The results showed that crane habitat vulnerabilities were significantly sensitive to the water level changes of Poyang Lake; the habitat vulnerabilities and their spatial distribution patterns both exhibited specific tendencies with water level increases. A water level of 12 m was identified as the potential upper threshold for the maintenance of sustainable crane habitats and a water level interval of 9–10 m was expected to be the optimal interval for facilitating the aggregation features of crane habitats. The water level interval was identified as the most dominant factor in habitat vulnerability. It explained 14.46%, 42.89%, and 21.78% of the sustainability, stability, and variety of crane habitats; the numbers were expected to increase to 22%, 49.25%, and 25.84%, respectively, with water level intervals interacting with other factors. This article provides a novel perspective in evaluating the habitat vulnerabilities of wintering migratory birds and quantifying the responses to water level changes in wetlands; the proposed approaches are applicable and practicable for habitat vulnerability assessments of other wintering birds in other typical wetlands.

Field studies on a variety of organisms have suggested that environmental variability plays a major role in determining spatial patterns in distribution and species diversity of estuanne organisms due to the effect of abiotic fluctuations on the physiology of animals. However, there is no study examining the effect of environmental variability on zooplankton distribution and diversity in estuaries. As vertical m~gration is obligatory behavior for the retention of planktonic animals at intermediate positions in the St. Lawrence Estuary (Canada), vertical stratification of the water column is considered the major source of environmental variability for zooplankton in this system. To evaluate the importance of this source of variability as a factor controlling the distribution and diversity of zooplankton in the estuary, we examined the relative contribution of each of the environmental factors of salinity, temperature, turbidity and vertical stratification in explaining spatial patterns of summer zooplankton distribution and diversity. Multivariate analyses revealed the presence of a longitudinal succession of seasonally stable species assemblages (tidal freshwater, true-estuarine and euryhalinemarine assemblages) whose spatial distribution was mainly a function of salinity and vertical stratification. Turbidity and temperature played a minor role in explaining spatial distribution. For all sampling periods, the limit between the true-estuarine and euryhaline-marine assemblages, the lowest number of population centers and the lowest zooplankton abundance all corresponded to the most vertically stratified waters. In contrast, population centers of all species were concentrated in the most abiotically stable parts of the estuary. We conclude that environmental variability is a major factor determining zooplankton distribution and diversity in the estuary. The spatio-temporal stability of the species assemblages and the seasonal variabihty in the abundance of some species also suggest that trophic interactions may play an important role in the regulation of zooplankton populations in the estuary.