Spatial Distribution Of Litter Research Articles

GENII: A graph neural network-based model for citywide litter prediction leveraging crowdsensing data

Plastic litter and its associated environmental hazards have garnered global attention in recent years, highlighting the need for effective management. Improper handling of plastic litter can lead to environmental degradation, making it crucial to address this issue. In this paper, we propose an innovative approach to predict the spatial distribution and quantity of plastic litter at the city level by leveraging crowd-sensing data and designing a graph neural network-based model. Meteorological data is specifically used to enhance temporal correlation, while the spatial distribution of litter is clustered using the K-means method to capture spatial correlation. For each cluster, multiple graphs are constructed based on the points of interest (POIs) and litter distribution within the cluster. Graph attention neural networks and heterogeneous graph attention networks are then utilized to aggregate the adjacency information and overall structural information of these graphs, respectively. Finally, the litter prediction results are obtained through multiple fully connected layers. Real-world experiments convincingly demonstrate the high effectiveness of our proposed model in predicting city-wide litter, surpassing multiple comparative models. All the code and datasets can be accessed from the GitHub repository at https://github.com/ZJUDataIntelligence/Genii.

Spruce forest litter structure, distribution, and water retention along hiking trails in the Ukrainian Carpathians

Almost 24% of the Ukrainian Carpathian ecosystems are assigned to the conservation fund due to their ecological values and attraction to numerous tourists. The forest litter in mountain forest stands plays an important role in terms of its ability to mitigate the impact of tourist activities, and erosion processes along with its contribution to the soil mineralization. Water interception, infiltration, and retention ability of forest litter have an impact on hydrological processes of forest ecosystems. At the same time, the accumulation and spatial distribution of litter can be affected not only by environmental conditions, but also by tourism. In this study, 13 Norway spruce (Picea abies L.) stands distinguished by average distance to the trail were chosen to investigate whether there are any differences in litter structure, water retention, and infiltration abilities as well as litter accumulation in areas along popular hiking trails in the Ukrainian Carpathians. Results showed that the litter thickness has increased with altitude and slope steepness. Moreover, results of one-way ANOVA demonstrate a significant difference (P < 0.05) in litter stock between two groups of sample plots: established directly to adjoin hiking trails and at a distance. Therefore, the forest litter stock nearby hiking trails may indicate that trampling caused by tourists has a negative impact on litter accumulation. However, no statistical difference was found (P > 0.05) in the accumulation of litter along three trails and altitudes across all surveyed forest stands. Results of the immersion test showed that the litter infiltration rate has a significant negative correlation with the maximum mass of absorbed water (r = –0.62, P < 0.05), litter stock (r = –0.69, P < 0.01), and retained precipitation (r = –0.62, P < 0.05). Despite our assumption, the infiltration rate was lower for sites distanced from the hiking trail in comparison with adjoining ones. According to our measurements, the water holding capacity of the litter varies from 42.3 t·ha<sup>–1</sup> to 187.3 t·ha<sup>–1</sup> regardless of the stand composition. Further, the precipitation amount retained by litter varies between 4.2 mm and 18.7 mm. Insignificant differences in litter fractional structure and accumulation were observed in pure spruce stands and mixed spruce-beech with an admixture of beech up to 20%. Further observational and modelling studies are necessary to clarify the role of the beech share in stand composition in relation to fractional structure and water interception and retention ability.

A nationwide assessment of litter on China’s beaches using citizen science data

China is the largest plastic consumer in the world. Despite its plastic waste import ban in 2017, this populous economy inevitably generates a large amount of waste, including plastic waste, a considerable part of which has become marine litter. Data from the 2018 National Coastal Cleanup and Monitoring Project, the largest beach litter monitoring activities using the citizen science approach in China, have been retrieved and analyzed to understand spatial patterns, composition, and original usage of marine litter. Within this project, 24 beaches were surveyed every two months. As a result, the mean density was 3.85 ± 5.39 items m−2, much higher than that reported by previous studies in China. There were great differences in the spatial distribution of litter. The highest densities appeared in the runoff-affected area of the Yangtze River, which was another difference from previous studies. Low-density, easy-to-transport foamed plastics were the major contributor to marine litter in these areas. Along China’s coast, approximately 90% of litter was from land-based sources, and over half of that originated from domestic sources. Including foamed plastic products, plastic litter with low recycling value dominated. Both natural and human factors influencing the spatiotemporal distribution and composition of litter are discussed. Socioeconomic factors, such as the lifestyle and consumption levels of citizens and local waste management systems, are possible explanations for the low-value characteristic of marine litter. The deviation between previous data and citizen science data in this study may be caused by many factors. Based on the discussion on these factors, some suggestions for citizen science research in China are also put forward.

Surface water circulation develops seasonally changing patterns of floating litter accumulation in the Mediterranean Sea. A modelling approach

Marine litter and, particularly, plastics are a growing concern at global scale. The Mediterranean Sea is among the zones in the world with the highest concentration of floating plastic debris. However, our knowledge remains limited on the spatial distribution of litter across this basin. Here, a set of different numerical model simulations were conducted to examine the dynamic conditions of the surface layer of the Mediterranean and how this drives the circulation and accumulation of floating litter. Seasonal dynamics of surface water circulation led to contrasting distribution patterns of floating litter along the year. Multiple hot spots of litter zones appeared across the basin in summer, while litter disperses and moves towards the Eastern Mediterranean and nearshore waters in winter. Taking into account such seasonal variability in the spatial patterns of litter in the Mediterranean seems to be key in the design of further sampling surveys and management strategies.

Anti-Erosion Litter Properties of Park Plants in Complex Terrain

Power , composition , the spatial distribution of litter , depending on the composition of plants and terrain conditions ( exposure , and the swiftness of the slope ) are investigated . Reserve, fractional composition and the absolute dry weight of litter are identified. As a result of research 63 samples of litter plants at 21 temporary plots in complex terrain in Golosiivskiy Park of Culture and Rest named after M. Rylskiy in Kiev established the water-physical parameters of the litter (weight of absorbed water, foliate litter coefficient, moisture capacity) seven species of woody plants, that grow on the slopes steepness before 26 o .

Spatial distribution of the fruiting bodies of Agaricales in a Japanese red pine (Pinus densiflora) forest

To examine the effect of the spatial distribution of litter and intergeneric interaction on the spatial distribution of agaric fruiting bodies, we surveyed spatial distribution of fruiting bodies of Agaricales in a mixed forest dominated by Pinus densiflora (Sieb et Zucc.) from July 1999 to July 2002. Three 10 × 10-m plots with different vegetation and positions on a slope were established: Top-Mixed, Top-Pinus, and Bottom-Pinus. Litter thickness in the Top-Mixed plot was the thinnest among the three plots. During the study, we counted 3563 fruiting bodies in 27 genera from 13 families. The dominant genera were Collybia, Marasmius, Mycena, Rhodophyllus, and Lactarius, and showed an intrageneric aggregated distribution at a quadrat size of 1m2. Collybia and Lactarius formed fruiting bodies in arcs. The spatial distribution of Collybia, Marasmius, and Lactarius fruiting bodies tended to overlap in two consecutive years. In the Top-Mixed plot, the number of Marasmius fruiting bodies increased with increasing litter thickness, while that of Lactarius decreased with litter thickness. Values of C'δ indicating degree of overlap were calculated for particular pairs of dominant fungal genera and the values differed between plots and years: for example, fruiting bodies of Marasmius and Mycena in the Bottom-Pinus plot were distributed aggregately in 1999 and 2000, but randomly in 2001, while they were distributed segregatedly in the Top-Pinus plot every year. Our study suggests that the spatial distribution of fungal fruiting bodies is affected by the distribution of litter in and between plots and that fungal flora is affected by vegetation.

Earthworms and litter distribution affect plant-defensive chemistry.

Studies on plant-defensive chemistry have mainly focused on plants in direct interaction with aboveground and occasionally belowground herbivores and pathogens. Here we investigate whether decomposers and the spatial distribution of organic residues in soil affect plant-defensive chemistry. Litter concentrated in a patch (vs. homogeneously mixed into the soil) led to an increase in the aucubin content in shoots of Plantago lanceolata. Earthworms increased total phytosterol content of shoots, but only when the litter was mixed homogeneously into the soil. The phytosterol content increased and aphid reproduction decreased with increasing N concentration of the shoots. This study documents for the first time that earthworms and the spatial distribution of litter may change plant-defensive chemistry against herbivores.

Geography and Fieldwork at the Secondary School Level: An Investigation of Anthropogenic Litter on an Estuarine Shoreline

Teaching geography within a field-based, environmental-problem-solving framework integrates geographic knowledge and practice and introduces high school students to skills required to undertake geographic research. A five-day field investigation on coastal geography was designed for juniors at a science high school in New Jersey. The goal of the field investigation was to allow students to engage in problem-solving, gather field data, apply geographic concepts and tools, and foster the ability to think critically. The purpose of the investigation was to identify the spatial distribution of litter on a beach and interpret the distribution based on physical and human processes. The field site is a 400-m-long shoreline reach in Raritan Bay, New Jersey. Students defined the term “litter” for purposes of the investigation, developed a classification system, and mapped the location and type of litter on the beach. Three sampling grids were established across the beach from the dune crest to the waterline. Students conducted topographic surveys of the sampling grids, collected litter in each grid cell, and counted, classified, and weighed the litter. Data gathered were reduced, analyzed, and interpreted based on the published literature. Findings were presented at a formal presentation on the last day of the investigation. Students submitted a written report and presented the results of the investigation at a student conference two months later. Field investigations can expose students to different methods of data sampling and measurement. Collaboration between secondary schools and universities can result in successful learning initiatives that allow students the opportunity to experience the role of a practicing professional.

Spatial distribution of litter and microarthropods in a Chihuahuan desert ecosystem

Plant litter accumulated along the edges of small water courses where plants caused formation of eddy currents during heavy rains. Only small amounts of plant litter accumulated under shrubs on sloping erosional areas when compared to shrubs on flat areas. Microarthropod densities ranged from 146. m−2 in unvegetated areas to 3103. m−2 under shrubs in small water courses. Microarthropod density was directly correlated with amount of surface litter (r = 0·987). Prostigmatid mites of the family Nanorchestidae were found in all habitats and Prostigmatids were the most numerous Acarina in all but one area. Collembola were found only in unvegetated areas of a large wash.