Amount Of Litter Research Articles

Review of the Policy, Social, Operational, and Technological Factors Affecting Cigarette Butt Recycling Potential in Extended Producer Responsibility Programs

Cigarette butts (CBs) are the most diffuse waste in the world, often abandoned into the environment without proper disposal. They are dangerous because of the numerous harmful chemicals potentially released by them into the environment. In the literature, there are several technological options for CB recycling, but some critical concerns could affect their effectiveness due to the quality and quantity of CB litter that is collected in the proper way. The extended producer responsibility scheme for CBs is proposed at the Europe level as an action to tackle CB litter and encourage sustainable product development. The present paper focuses on analyzing the existing literature to identify critical issues within the policy framework, social behavior, waste collection and transport, and technological processes. The collection and transport of CB waste is a major issue, being a key step for bringing CB to the recycling process. The main concern is the small quantity of CBs collected: 0.06% of the municipal waste and 0.18% of the unsorted waste in the case study’s administrative area of Perugia. Another crucial issue is the need for behavioral interventions to increase education and awareness of citizens that are smokers, addressing the discrepancy between smokers’ behaviors and beliefs. The main results, along with the critical issues related to the topics, are highlighted.

Biodegradation of plastics in the pelagic environment of the coastal zone – Proposed test method under controlled laboratory conditions

The increasing quantities of plastic litter accumulated in the oceans, including microplastics, represent a serious environmental threat. Despite the recent legislative actions, the plastic littering problem will not disappear in a short time. It may, however be ameliorated by replacing conventional non-degradable plastics with bio-based materials biodegradable in marine environment (targeting the non-recycled or mismanaged plastic waste). Although priority is set to prevention of plastic litter by means of the circular economy principles, biodegradability is a means of controlling unintentional plastic pollution. In this effort, the development of reliable test methods that would be used along with standard specifications for determining the biodegradability of novel polymeric materials or plastics in marine environments, is a necessary complementary component of the whole strategy to control the marine plastic litter and micro-, nano-plastics threat. The present work focuses on identifying gaps and improving available laboratory test methods for measuring the aerobic biodegradation of plastics in the seawater column within the coastal zone (pelagic environment). The research work followed a methodology that is based on recommendations of ASTM D6691:2017 concerning biodegradation of plastics in the seawater and the similar ISO 23977-1:2020. Three different implementation schemes of the test method were applied using different experimental setups and measuring techniques for monitoring the evolved CO2. The effect of critical parameters affecting nutrient adequacy (concentration in inoculum) and oxygen adequacy (bioreactor size, sample size, frequency of aeration) on the biodegradation of four tested materials was explored, and optimal values are proposed. The results allowed for the refinement of the proposed test method to improve reliability and reproducibility.

Effects of litter and root inputs on soil CH4 uptake rates and associated microbial abundances in natural temperature subalpine forests

Climate change altered the quantities of aboveground plant litter and root inputs, but the effects on soil CH4 uptake rates and underlying mechanisms remain unclear. To investigate these factors, a three-year detritus input and removal treatment (DIRT) study including six treatments (namely, CK, control; NL, litter removal; DL, double litter; NR, root exclusion; NRNL, root exclusion plus litter removal; and NRDL, root exclusion plus double litter) was conducted in broadleaf and coniferous forest subalpine forest ecosystems. The results showed that both the subalpine forest soils acted as sink for atmospheric CH4 across all treatments, while the broadleaf forest had consistently higher CH4 uptake rates than the coniferous forest. Based on the annual mean values, root exclusion (NR, NRNL and NRDL) significantly decreased soil CH4 uptake rates by 35.9 %, 31.0 % and 43.4 % in the broadleaf forest and 36.7 %, 31.9 % and 40.6 % in the coniferous forest compared with CK treatments, respectively. Meanwhile, the mean soil CH4 uptake rates were significantly reduced by 23.6 % and 17.3 % in the broadleaf forest and the coniferous forest under the DL treatments, respectively; nevertheless, the NL treatment significantly increased soil CH4 uptake rates by 19.68 % and 14.4 %, respectively. The results clearly demonstrated that root exclusion exerted a greater influence on soil CH4 uptake rates than plant litter manipulations. Correlation and redundancy analysis (RDA) revealed that the separation of root exclusion treatments from aboveground plant litter manipulations was based on higher soil water content, NH4+-N and NO3−-N concentrations, and lower DOC (dissolved organic carbon) concentrations and methanotroph pmoA gene abundance. The results suggest that future alterations in aboveground plant litter and root input, particularly a reduction in root input, can exert a stronger influence on regulating soil CH4 uptake than aboveground litter manipulations in subalpine forests with cold and humid climatic conditions in response to future climate scenarios.

Insects in the city: Determinants of a contained aquatic microecosystem across an urbanized landscape.

Cities can have profound impacts on ecosystems, yet our understanding of these impacts is currently limited. First, the effects of the socioeconomic dimensions of human society are often overlooked. Second, correlative analyses are common, limiting our causal understanding of mechanisms. Third, most research has focused on terrestrial systems, ignoring aquatic systems that also provide important ecosystem services. Here we compare the effects of human population density and low-income prevalence on the macroinvertebrate communities and ecosystem processes within water-filled artificial tree holes. We hypothesized that these human demographic variables would affect tree holes in different ways via changes in temperature, water nutrients, and the local tree hole environment. We recruited community scientists across Greater Vancouver (Canada) to provide host trees and tend 50 tree holes over 14 weeks of colonization. We quantified tree hole ecosystems in terms of aquatic invertebrates, litter decomposition, and chlorophyll a (chl a). We compiled potential explanatory variables from field measurements, satellite images, or census databases. Using structural equation models, we showed that invertebrate abundance was affected by low-income prevalence but not human population density. This was driven by cosmopolitan species of Ceratopogonidae (Diptera) with known associations to anthropogenic containers. Invertebrate diversity and abundance were also affected by environmental factors, such as temperature, elevation, water nutrients, litter quantity, and exposure. By contrast, invertebrate biomass, chl a, and litter decomposition were not affected by any measured variables. In summary, this study shows that some urban ecosystems can be largely unaffected by human population density. Our study also demonstrates the potential of using artificial tree holes as a standardized, replicated habitat for studying urbanization. Finally, by combining community science and urban ecology, we were able to involve our local community in this pandemic research pivot.

Effects of different vegetation components on soil erosion and response to rainfall intensity under simulated rainfall

Vegetation effectively prevents soil erosion, however, the reductions in runoff and erosion caused by the different components of vegetation are unclear. Under simulated rainfall intensities (60, 90, and 120 mm h−1) and litter amount (5, 15, and 25 g m−2), five different treatments were established: intact grass (IG), litter and roots (LR), canopy and roots (CR), only litter (OL), only roots (OR), and a control bare plot (CK). The effects of the canopy, roots, and litter on erosion were quantitatively analysed. (1) The runoff rate and erosion rate were reduced by different treatments, and the IG treatment most effectively reduced runoff and sediment, followed by the LR, OL, CR, and OR treatments. (2) The velocity, runoff, and sediment reductions by litter were optimal. The velocity and runoff reduction effects of the roots were stronger than those of the canopy, reducing the sediment reduction more than the litter at 5 g m−2. The velocity, runoff, and sediment reductions produced by the canopy were weak, providing average contributions of 11.40%, 8.01%, and 7.34%, respectively. The vegetation more strongly affected sediment than runoff reduction. (3) Different treatments most effectively reduced runoff and sediment under a 60 mm h−1 rainfall. The contributions of the canopy, roots, and litter to reducing runoff and sediment decreased with increasing rainfall intensity. (4) Erosion rate and shear stress showed a linear relationship. The soil erodibility Kr and critical runoff shear stress τc of the IG plot were lowest and highest, respectively. Litter and roots decreased Kr and increased τc, respectively. Compared with the bare plot, Kr decreased by 44.44%–61.54% and 15.38%–40.74% and τc increased by 3.85%–7.44% and -1.65% to 7.69% in litter and roots, respectively. This study provides insights regarding the mechanism through which vegetation controls erosion and effective scientific basis for rational vegetation allocation.

Long Term Seasonal Variability on Litterfall in Tropical Dry Forests, Western Thailand

Nutrient recycling is one of the most important services that supports other processes in ecosystems. Changing litterfall patterns induced by climate change can cause imbalances in nutrient availability. In this study, we reported the long-term (28-year) interplay between environmental factors and variability among litterfall fractions (leaves, flowers, and fruit) in a tropical dry forest located in Kanchanaburi, Thailand. A long-term litter trap dataset was collected and analyzed by lagged generalized additive models. Strong seasonality was observed among the litter fractions. The greatest leaf and flower litterfall accumulated mostly during the cool, dry season, while fruit litterfall occurred mostly during the rainy season. For leaf litter, significant deviations in maximum temperature (Tmax), volumetric soil moisture content (SM), and evapotranspiration (ET) during the months prior to the current litterfall month were the most plausible factors affecting leaf litter production. Vapor pressure deficit (VPD) and ET were isolated as the most significant factors affecting flower litterfall. Interestingly, light, mean temperature (Tmean), and the southern oscillation index (SOI) were the most significant factors affecting fruit litterfall, and wetter years proved to be highly correlated with elevated fruit litterfall. Such environmental variability affects both the triggering of litterfall and its quantity. Shifting environmental conditions can therefore alter nutrient recycling rates through the changing characteristics and quantity of litter.

Detection and mapping of water and chlorophyll-a spread using Sentinel-2 satellite imagery for water quality assessment of inland water bodies.

Water quality monitoring of reservoirs is currently a significant challenge in the tropical regions of the world due to limited monitoring stations and hydrological data. Remote sensing techniques have proven to be a powerful tool for continuous real-time monitoring and assessment of tropical reservoirs water quality. Although many studies have detected chlorophyll-a (Chl-a) concentrations as a proxy to represent nutrient contamination, using Sentinel 2 for eutrophic or hypereutrophic inland water bodies, mainly reservoirs, minimal efforts have been made for oligotrophic and mesotrophic reservoirs. The present study aimed to develop a modeling framework to map and estimate spatio-temporal variability of Chl-a levels and associated water spread using the Modified Normalized Difference Water Index (MNDWI) and Maximum Chlorophyll Index (MCI). Moreover, the impact of land use/land cover type of the contributing watershed in the oligo-mesotrophic reservoir, Bhadra (tropical reservoir), for 2018 and 2019 using Sentinel 2 satellite data was analyzed. The results show that the water spread area was higher in the post-monsoon months and lower in the summer months. This was further validated by the correlation with reservoir storage, which showed a strong relationship (R2 = 0.97, 2018; R2 = 0.93, 2019). The estimated Chl-a spread was higher in the winter season, because the reservoir catchment was dominated by deciduous forest, producing a large amount of leaf litter in tropical regions, which leads to an increase in the level of Chl-a. It was found that Chl-a spread in the reservoir, specifically at the inlet sources and near agricultural land practices (western parts of the Bhadra reservoir). Based on the findings of this study, the MCI spectral index derived from Sentinel 2 data can be used to accurately map the spread of Chl-a in diverse water bodies, thereby offering a robust scientific basis for effective reservoir management.

Methodology to quantify single-use plastic products in municipal solid waste Part 2: Quantification of tobacco products with filters in Germany.

Discharge from unrestricted tobacco products with filters (TPF) causes environmental damage. To reduce TPF litter quantities, Directive (EU) 2019/904 requires TPF producers to proportionally contribute to the costs of discarding their products in public waste collection systems, including litter waste ones. An appropriate output-based cost model requires assessing TPF quantities in relevant waste streams. Currently, there is no comprehensive data available on TPF quantities in municipal solid waste (MSW). Therefore, a case study was conducted to quantify TPF in MSW. This study aimed to determine TPF quantities (1) in residual waste from four German district types and (2) in waste from public collection systems for three settlement structures within Trier City. Relevant waste streams from public collection systems, namely waste from public waste receptacles, street-cleaning waste and sinkhole residues, were identified. For both sampling campaigns, consideration was given to extrapolating the results to a larger scale. The results showed that the average specific TPF quantities in residual waste were 277.7, 271.8, 193.3 and 204.5 gi- 1a- 1 in the selected city district, urban district, densely populated rural district and sparsely populated rural district, respectively. Extrapolation of these results to Germany yielded a specific TPF quantity in residual waste of 250.3 gi-1a-1. The average specific TPF quantities in waste from public waste receptacles, street-cleaning waste and sinkhole residues were 12.2, 47.4 and 9.9 gi-1a- 1, respectively. The results could contribute to cost model development based on Directive (EU) 2019/904.

Temperate food forest soil and dead organic matter carbon content relative to adjacent land

AbstractSoil is identified as the terrestrial carbon (C) pool with the highest potential for C sequestration. This study therefore examined the soil organic carbon (SOC) under four different but adjacent land‐use systems in the temperate climate zone: a food forest, redwood forest, pasture land and agricultural field in Dartington, UK. Soil samples were collected at 0‐ to 20‐cm and 20‐ to 40‐cm depth at all four sites. Two soil fractionation methodologies were applied as well as analysis for C content. Additionally, carbon content from dead organic matter (DOM) was estimated from the woody and non‐woody litter in the food forest and redwood forest. Similar total SOC was found between all four systems. However, due to the difference in turnover rates of C in different soil fractions, the food forest soil exhibited a similar long‐term storage of C as the redwood forest, while pasture land and agricultural field stored less C in the long term. The redwood forest exhibited a higher non‐woody litter C content than the food forest, but similar amounts of coarse and fine woody litter.

The tourism industry keeps beaches clean in Mozambique

In this study, we conducted the first assessment of the litter abundance, diversity and predictors in Mozambique, by collecting approximately 2 tons of litter along six beaches across the country. We tested whether population, touristic industry, fishing, and recreation activities predict the quantity of macro litter for each of the 11 types and 141 subtypes of litter. Overall, we found that plastics made up 60.1 % of the items across all sampled beaches. Following plastics, clothing objects accounted for the second most weight (20.4 %) while foam objects were the second most abundant (15.7 %). More importantly, our results show that the tourism industry is a strong predictor for lower levels of litter across most types of litter while population density and fishing activity were strong predictors for higher levels. Our findings suggest that the tourism industry plays a crucial role in the country by maintaining the beaches clean.

Public participation in beach clean-up activities to raise awareness and reduce marine litter for the protection of the Black Sea ecosystem

Human activities and poor awareness are believed to be responsible for marine litter pollution. In the scope of the European Union, Cross Border Cooperation, and Black Sea Basin (EU, CBC, BSB - 785) LitOUTer Project, “Raising Public Awareness and Reducing Marine Litter for the Protection of the Black Sea Ecosystem”, beach clean-up activities have been conducted. A beach clean-up activity was conducted at the Kıyıcık Beach, Trabzon, Turkiye involved by Stakeholders, NGOs, middle to high school, university students, teachers, and lecturers. This study aims to reveal the amount of marine litter at Kıyıcık Beach through public participation in beach clean-up activities. A total of 4488 solid wastes (∼100 kg) were collected and removed from the beach. The waste composition consisted of 50% plastic, 22% metal, 10% glass, 8% paper, 4% cloth, 1% metal, and 4% Covid-19-related waste. Plastic pieces, plastic bottles, and caps dominated the plastic litter on the beach. Moreover, 119 single-use face masks (Covid-19-related waste) were collected. Single-use plastic waste in the environment implies the impact of human activities and a lack of awareness regarding marine litter. Public participation in beach clean-up activities is expected to raise individual awareness and reduce marine litter to protect the Black Sea Ecosystem.

Vegetation patch dynamics in rangelands: How feedbacks between large herbivores, vegetation and soil fauna alter patches over space and through time

AbstractAimLarge herbivore grazing is a popular conservation management tool to promote vegetation structural diversity of rangelands. However, vegetation patch dynamics, that is, how patches of grazing‐defended tall vegetation and grazer‐preferred short lawns shift over space and time, is poorly understood. Here, we describe a new conceptual framework for patch dynamics within rangelands, combining theories of classical cyclical succession, self‐organization and multitrophic feedbacks between grazers, vegetation and bioturbating soil fauna.LocationWe use the cattle‐grazed salt marsh of the island Schiermonnikoog, The Netherlands, as a model system. The grazed salt marsh is characterized by distinct tall vegetation patches dominated by the grazing‐defended rush Juncus maritimus and grazing‐intolerant grass Elytrigia atherica, surrounded by a matrix of grazing lawn (dominated by Festuca rubra).The FrameworkBased on previous observational and experimental studies, we propose a cyclical patch dynamic where plant species composition and structure transitions through four phases: patch initiation (a) occurs when the grazing‐defended rush J. maritimus establishes in the grazed lawn. Patch establishment (b) follows when the grazing‐intolerant grass E. atherica establishes in the patch due to associational defence by J. maritimus and produces a large amount of litter that attracts the key bioturbating amphipod Orchestia gammarellus. Patch expansion (c) occurs when O. gammarellus activities improve soil properties of the patch, which favours E. atherica growth, leading to E. atherica competitively displacing J. maritimus in the centre of the patch. Patch degeneration (d) follows when cattle enter the enlarged patch to consume E. atherica in the centre, trample the soil, displace O. gammarellus and decrease vegetation cover, opening space for grazing‐lawn species to invade. The cycle restarts when remnants of the rush J. maritimus in the degenerated patches (or individuals recently established from seed dispersal) initiate new patches in the grazing lawn.SynthesisOur proposed patch‐dynamic model provides a means to describe the mechanisms driving vegetation patch dynamics and serves as a foundation for further experimental and observational exploration, not only for this specific system, but more generally for grazed systems worldwide that show patches of typical grazing‐defended and grazer‐preferred vegetation.

A dataset of monthly and yearly litterfall production in different succession stages of evergreen broad-leaved forests in Tiantong (2008 – 2018)

Litter production is an important part of the matter cycle of forest ecosystems, which plays an important role in maintaining forest soil fertility and promoting ecosystem nutrient cycling. Additionally, it serves as an important indicator for the quantification of ecosystem function such as forest productivity and carbon balance. The data in the dataset are from two observation plots in Zhejiang Tiantong National Forest Ecosystem National Observation and Research Station. The community succession types in the above two pilots belong to the middle-late stage and mature stage of evergreen broad-leaved forest succession, respectively. The projected area of each plot is 50 m × 50 m. There are 27 litter traps of 0.5 m2 in each plot. We collected and counted the data in terms of litter components, i.e. branches, leaves, flowers (fruits), bark and debris). The dataset includes the monthly and annual production of each component and the total amount of litter in the two plots from 2008 to 2018. The data have been checked against the original paper records, as well as the dynamic trend of data in the same period, so as to ensure data quality control and accuracy assessment. This dataset can provide basic information for understanding the changes of ecosystem structure and function during the succession process of evergreen broad-leaved forests. Moreover, it can also provide data support for studying the impact of regional climate change on the forest ecosystem and the assessment of carbon balance in the zone of evergreen broad-leaved forests.

Land-derived litter load to the Indian Ocean: a case study in the Cimandiri River, southern West Java, Indonesia.

The first study related to the characteristics of the riverine litter was carried out at the mouth of the Cimandiri River in the southern West Java to provide a national database, as mandated in the Indonesian Presidential Regulation 83/2018 concerning the handling of marine debris. We examined floating riverine litter entering the South Java Sea at Cimandiri River outlets four times between December 2020 and October 2021 using a Thomsea 1T trawl-net. The amount of litter collected tended to rise throughout the sampling period. Daily floating riverine litter released into the South Java Sea was estimated to be 285,931 ± 133.70 items or 307 ± 192.69kg. Our monitoring data revealed no sampling period differences in litter release into the South Java Sea with no correlation with rainfall. Our data indicate that plastics are the most single abundant type of floating riverine litter entering the South Java Sea from the Cimandiri River, accounting for 99.92% of abundance (285,701 ± 133,464.75 items per day) or 97.78% in terms of weight (300 ± 181.99kg per day) of the total litter collected. As the Cimandiri River is one of the major rivers with an outlet in the south of Java, this land-derived litter information could be an archetype for riverine ecosystems in the nation and region.

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.

Hock Lesions in Dairy Cows in Cubicle Housing Systems in Germany: Prevalence and Risk Factors.

Hock lesions in dairy cows are an important indicator of animal welfare, in particular housing conditions. The aim of this study was to assess the prevalence of hock lesions in dairy cows kept in cubicle housing systems in three structurally different regions of Germany and to derive recommendations from risk factor analyses. Lactating and dry cows kept in cubicle housing systems were assessed for hock lesions (north: 206 farms with 20,792 cows; south: 156 farms with 8050 cows; east: 192 farms with 37,839 cows). Risk factor analyses were conducted using multi-factorial logistic regression models. The median prevalence of hock lesions (hairless patches, wounds, and/or swelling) at farm level was 79.8% (SD: 25.0; north), 66.2% (SD: 31.0; south), and 78.5% (SD: 26.3; east). The mean prevalence of severe hock lesions (wounds and/or swelling) at farm level was 12.5% (SD: 11.3; north), 8.0% (SD: 13.5; south), and 14.4% (SD: 17.9; east). Cows kept in pens with rubber mats or mattresses (with or without a small amount of litter) had a particularly higher chance of hock lesions compared with cows kept in pens with deep-bedded cubicles (OR: north: 3.1 [2.3-4.2]; south: 8.7 [5.9-13.0], east: 2.0 [1.7-2.4]). The study showed that hock lesions are a widespread problem on German dairy farms with cubicle housing systems. Deep-bedded cubicles are likely to reduce hock lesions and increase cows' comfort.

Increasing risk of invasions by organisms on marine debris in the Southeast coast of India

Increasing amount of anthropogenic litter in the marine environment has provided an enormous number of substrates for a wide range of marine organisms, thus serving as a potential vector for the transport of fouling organisms. Here, we examined the fouling organisms on different types of stranded litter (plastic, glass, rubber, foam sponge, cloth, metal and wood) on eight beaches along the southeast coast of India. In total, 17 encrusting species belonging to seven phyla (Arthropoda, Bryozoa, Mollusca, Annelida, Cnidaria, Chlorophyta and Foraminifera) were identified on 367 items, with one invasive species, the mussel Mytella strigata, detected. The most common species associated with marine litter were the cosmopolitan bryozoans Jellyella tuberculata (%O = 31.64 %) and J. eburnea (28.61 %), the barnacle species Lepas anserifera (29.97 %), Amphibalanus amphitrite (22.34 %) and Amphibalanus sp. (14.16 %), and the oyster species Saccostrea cucullata (13.62 %) and Magallana bilineata (5.44 %). We also reported the first records on stranded litter of four species: the gastropod species Pirenella cingulata and Umbonium vestiarium, the foraminiferan Ammonia beccarii, and the oyster M. bilineata. This study is thus the first documentation of marine litter as a vector for species dispersal in India, where the production and consumption of plastic rank among the highest in the world. We also highlight the increasing risk of invasions by non-indigenous organisms attached to debris along the southeast coast of India. Comprehensive monitoring efforts are thus needed to elucidate the type of vectors responsible for the arrival of invasive species in this region. Raising awareness and promoting education are vital components in fostering sustainable solutions to combat plastic pollution in the country and globally.

Seed germination characteristics of Polygonum longisetum (Polygonaceae) with reference to wildfire

The seed germination of Polygonum longisetum (Polygonaceae) was examined in relation to wildfire, i.e. smoke, soil surface substrates (charcoal and wood ash), litter (fresh and crushed) and water potential because this species is widely distributed as an invasive species and has the ability of smoke-induced seed germination. Previous studies confirm that this species requires light and cold stratification for high seed germination. The effects of seed density and fertilizer on seed germination and seedling growth were also examined. Seed germination was highest at a certain concentration of smoke liquid, while it was lower on woody ash and higher without litter. Since seed germination decreased more with lower water potential, low seed germination on litter and substrates should be induced by water limitation. Seed density and fertilizer did not affect germination rates but changed biomass and shoot height. In conclusion, the effects of smoke liquid on seed germination changed synchronously with the quality and quantity of litter and substrates. These seed characteristics should be advantageous for germination in dry habitats after wildfires and other disturbances.

Youth4Sea and marine debris: An arts-based, site-specific, youth-framed inquiry

This arts-based project engaged youth (between 18 and 24 years of age) living in Byron Bay to co-design an inquiry addressing the increased pollution created during the period of Schoolies. Through a youth-framed participatory research design, the project team engaged local youth in researching young people’s marine pollution understandings, attitudes and behaviours. It then supported their ideas as they created, instigated and assessed an intervention campaign, targeted at Schoolies tourists, to reduce the amount of beach litter (). The young people conducted video interviews with their peers, created visual diaries, took photographs, and designed and implemented an intervention plan. Seeking a feasible action and realizing the enormity of the issue of marine pollution, they decided to target the beach as a specific site for intervention, and in particular, the issue of cigarette butt litter. The young people then engaged in a suite of arts-based analyses, including photographs of the intervention in-process, a documentary film, visual diaries () and a collaborative, large-scale canvas painting (; ) as an analytical riposte.

Shading contributes to Sphagnum decline in response to warming.

Experimental warming of an ombrotrophic bog in northern Minnesota has caused a rapid decline in the productivity and areal cover of Sphagnum mosses, affecting whole-ecosystem carbon balance and biogeochemistry. Direct effects of elevated temperature and the attendant drying are most likely the primary cause of the effects on Sphagnum, but there may also be responses to the increased shading from shrubs, which increased with increasing temperature. To evaluate the independent effects of reduction in light availability and deposition of shrub litter on Sphagnum productivity, small plots with shrubs removed were laid out adjacent to the warming experiment on hummocks and hollows in three blocks and with five levels of shading. Four plots were covered with neutral density shade cloth to simulate shading from shrubs of 30%-90% reduction in light; one plot was left open. Growth of Sphagnum angustifolium/fallax and S. divinum declined linearly with increasing shade in hollows, but there was no response to shade on hummocks, where higher irradiance in the open plots may have been inhibitory. Shading caused etiolation of Sphagnum-they were thin and spindly under the deepest shade. A dense mat of shrub litter, corresponding to the amount of shrub litter produced in response to warming, did not inhibit Sphagnum growth or cause increases in potentially toxic base cations. CO2 exchange and chlorophyll-a fluorescence of S. angustifolium/fallax from the 30% and 90% shade cloth plots were measured in the laboratory. Light response curves indicate that maximal light saturated photosynthesis was 42% greater for S. angustifolium/fallax grown under 30% shade cloth relative to plants grown under 90% shade cloth. The response of Sphagnum growth in response to increasing shade is consistent with the hypothesis that increased shade resulting from shrub expansion in response to experimental warming contributed to reduced Sphagnum growth.