Litter Reduction Research Articles

Marine litter in bottom trawls off the Portuguese coast

Benthic marine litter along the Portuguese coast, was recorded in 14 trips on stern trawlers covering a distance of 2117km and an area of 56.2km2, average depth range 90–349m. 2034 items of marine litter were registered, 76% were plastics and 38.6% were originated from fishing related activities. Plastic was present in all the trawls and had the highest average density of all litter categories, 50itemskm−2.The highest density of marine litter (178.9±64.0itemskm−2) was found in the proximity of the Tagus river mouth, probably related to the high population density in the Lisbon metropolitan area.This study highlights the need to raise fishermen awareness for the adoption of good environmental practices that will contribute to the reduction of marine litter.

Managing Canada Thistle (Cirsium arvense) in a Constructed Grassland with Aminopyralid and Prescribed Fire

Green spaces such as golf courses that intermingle within or exist on fringes of urban landscapes can provide opportunities for increasing the ecological value of urban areas. To that end, more naturalistic and less input-intensive “links”-style golf courses have recently gained favor over input-intensive parkland courses. The Osgood Public Golf Course in Fargo, ND is a links-style golf course set adjacent to suburban housing developments. This course incorporated large areas of prairie plantings, or “constructed grasslands,” which over time became dominated by fescue species and infested with Canada thistle. Our objective was to explore the efficacy of using prescribed fire combined with aminopyralid herbicide to control Canada thistle and promote a more diverse mix of warm-season C4 and cool-season C3 grasses. Aminopyralid was applied during fall 2010 and prescribed fire was applied during spring 2011. We found that aminopyralid provided excellent control of Canada thistle 1 and 2 yr post-treatment. Open niches created from Canada thistle control were readily filled by C3 grasses, primarily fescue species, which were the dominant species on the constructed grasslands prior to treatment. Fire intensity was variable within and across plots and was associated with reductions of litter and C3 grasses, but was not associated with increases of C4 grasses within the time frame of this study. Our results demonstrate the effectiveness of aminopyralid for Canada thistle control in constructed grasslands. Prescribed fire maintained C3 grass dominance while removing litter, but C4 grass response was variable and appeared dependent on pretreatment C4 species abundance. Reduction of litter in constructed grasslands dominated by fescue could potentially lead to microsite conditions that would favor C4 and other C3 species, especially if short-term management promoted additional facilitation efforts, such as repeat spring fire treatments and seeding.

Litter Reduction by Prescribed Burning Can Extend Downy Brome Control

Downy brome (Bromus tectorum L.) is a highly successful invasive species primarily because it fills an open niche in native plant communities. It also produces large amounts of litter over time. We hypothesized that removing accumulated litter with a prescribed burn before applying herbicides would improve herbicide efficacy, extending the duration of control. In January 2012, two downy brome-infested sites were burned. In March 2012, postemergent applications of glyphosate, imazapic, and tebuthiuron were made in a split-plot design. Above-ground biomass was collected at 6, 18, and 27 months after treatment (MAT) to evaluate treatment effects. In nonburned areas, all herbicide treatments were similar to the control 27 MAT; however, burning combined with imazapic or tebuthiuron reduced downy brome biomass 27 MAT by 81% ± 4.6 SE and 84% ± 19.3 SE, respectively. Remnant species responded positively to burning and herbicide treatments. Native cool-season grass biomass increased after burning whereas native warm-season grass biomass increased following tebuthiuron treatments. The impact of litter on imazapic and tebuthiuron availability was also evaluated. Herbicide interception increased in a linear relationship with increasing litter. For every 50 g · m−2 increase in litter there was a 7% increase in the amount of herbicide intercepted, meaning that 75% of the applied herbicide was intercepted by 360 g · m−2 of litter. A simulated rainfall event of 5 mm, 7 days after application, removed a significant amount of herbicide. This indicates that in sites with surface litter, timely precipitation could be critical for herbicide efficacy; however, when burning was used to remove litter and was followed by herbicides with residual soil activity, downy brome control was extended. Due to downy brome’s relatively short seed viability in the soil, extending herbicide efficacy to several years could help to reduce the soil seed bank.

Larger phylogenetic distances in litter mixtures: lower microbial biomass and higher C/N ratios but equal mass loss.

Phylogenetic distances of coexisting species differ greatly within plant communities, but their consequences for decomposers and decomposition remain unknown. We hypothesized that large phylogenetic distance of leaf litter mixtures increases differences of their litter traits, which may, in turn, result in increased resource complementarity or decreased resource concentration for decomposers and hence increased or decreased chemical transformation and reduction of litter. We conducted a litter mixture experiment including 12 common temperate tree species (evolutionarily separated by up to 106 Myr), and sampled after seven months, at which average mass loss was more than 50%. We found no effect of increased phylogenetic distance on litter mass loss or on abundance and diversity of invertebrate decomposers. However, phylogenetic distance decreased microbial biomass and increased carbon/nitrogen (C/N) ratios of litter mixtures. Consistently, four litter traits showed (marginally) significant phylogenetic signal and in three of these traits increasing trait difference decreased microbial biomass and increased C/N. We suggest that phylogenetic proximity of litter favours microbial decomposers and chemical transformation of litter owing to a resource concentration effect. This leads to a new hypothesis: closely related plant species occurring in the same niche should promote and profit from increased nutrient availability.

Low‐to‐moderate nitrogen and phosphorus concentrations accelerate microbially driven litter breakdown rates

Particulate organic matter (POM) processing is an important driver of aquatic ecosystem productivity that is sensitive to nutrient enrichment and.drives ecosystem carbon (C) loss. Although studies of single concentrations of nitrogen (N) or phosphorus (P) have shown effects at relatively low concentrations, responses of litter breakdown rates along gradients of low-to-moderate N and P concentrations are needed to establish likely interdependent effects of dual N and P enrichment on baseline activity in stream ecosystems. We established 25 combinations of dissolved inorganic N (DIN; 55-545 µg/L) and soluble reactive P (SRP; 4-86 µg/L) concentrations with corresponding N:P molar ratios of 2-127 in experimental stream channels. We excluded macroinvertebrates, focusing on microbially driven breakdown of maple (Acer rubrum L.) and rhododendron (Rhododendron maximum L.) leaf litter. Breakdown rates, k, per day (d-1) and per degree-day (dd-l), increased by up to 6X for maple and 12× for rhododendron over our N and P enrichment gradient compared to rates at low ambient N and P concentrations. The best models of k (d- and dd-1) included litter species identity and N and P concentrations; there was evidence for both additive and interactive effects of N and P. Models explaining variation in k dd-1 were supported by N and P for both maple and rhododendron (R =0.67 and 0.33, respectively). Residuals in the relationship between k dd-1 and N concentration were largely explained by P, but residuals for k dd-1 and P. concentration were less adequately explained by N. Breakdown rates were more closely related to nutrient concentrations than variables associated with measurements of two mechanistic parameters associated with C loss (fungal biomass and microbial respiration rate). We also determined the effects of nutrient addition on litter C: nutrient stoichiometry and found reductions in litter C:N and C:P along our experimental nutrient gradient. Our results indicate that microbially driven litter processing rates increase across low-to-moderate nutrient gradients that are now common throughout human-modified landscapes.

Direct identification of diverse alicyclic terpenoids in Suwannee River Fulvic Acid.

The chemical complexity of dissolved organic matter (DOM) obstructs our ability to definitively recover source compounds from within DOM, an objective which has the capacity to alter our understanding of carbon sequestration on a global scale. To advance compositional studies of DOM we have applied a previously published reduction method to an environmental standard, Suwannee River Fulvic Acid (SRFA). The reduction products, comprising 12% of the prereduced carbon, were then separated by comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOF-MS). Results indicate that the majority of observed reduced compounds corresponded to alicyclic hydrocarbons in the size range C10 to C17. Cyclic terpenoids are the only biomolecule class with contiguous, alicyclic carbon backbones of this size. These terpenoid reduction products contain series offset by CH2 and exhibit great isomeric diversity, features previously inferred from ultrahigh resolution mass spectrometry and NMR studies of unreduced SRFA. Reduction of Taxodium leaf litter as a source material to SRFA confirmed the prevalence of terpenoids in SRFA and provided insight into the parent compounds that must be diagenetically modified on relatively short time scales. These data corroborate several recent studies that suggest alicyclic hydrocarbons to be important components of longer-lived DOM.

Deep-sea litter: a comparison of seamounts, banks and a ridge in the Atlantic and Indian Oceans reveals both environmental and anthropogenic factors impact accumulation and composition

Marine litter is a global challenge that has recently received policymakers’ attention, with new environmental targets in addition to changes to old legislation. There are no global estimates of benthic litter because of the scarcity of data and only patchy survey coverage. However, estimates of baseline abundance and composition of litter are vital in order to implement litter reduction policies and adequate monitoring schemes. Two large-scale surveys of submarine geomorphological features in the Indian and Atlantic Oceans reveal that litter was found at all locations, despite their remoteness. Litter abundance was patchy, but both surveyed oceans had sites of high litter density. There was a significant difference in the type of litter found in the two oceans, with the Indian Ocean sites being dominated by fishing gear, whereas the Atlantic Ocean sites displayed a greater mix of general refuse. This study suggests that seabed litter is ubiquitous on raised benthic features, such as seamounts. It also concludes that the pattern of accumulation and composition of the litter is determined by a complex range of factors both environmental and anthropogenic. We suggest that the tracing of fishing effort and gear type would be an important step to elucidate hotspots of litter abundance on seamounts, ridges and banks.

Effects of roads on collembolan community structure in subtropical evergreen forests on Okinawa Island, southwestern Japan

Because roads through forested sites may affect the soil invertebrate community within the forest, we investigated collembolan community structure at various distances from roads running through subtropical evergreen forests on Okinawa, Japan. We hypothesized that collembolan communities near roads would be deleteriously affected due to the reduction of litter and changes in water conditions, and tree community composition as compared to those in the inner forest. Collembolan densities tended to be lower near roads (up to 1 m inside the forest) than in inner-forest regions (≥20 m from roads). Collembolan species richness in the soil was also affected by distance from the roadside. A decrease in collembolan density was associated with lower soil water content and changes in tree community composition (principally a decrease in Castanopsis sieboldii cover), but the accumulated litter weight had no significant effect, probably because accumulated litter levels were low. The extent of Bray–Curtis dissimilarity between collembolan communities located along roads decreased with distance from the roadside as compared to that of reference sites (>80 m from the roads). Separation of Bray–Curtis dissimilarities into two components revealed that differences between roadside communities and those of reference sites were largely explained by taxonomic turnover (i.e., individuals of certain species at one site were substituted with the same numbers of individuals of different species at another site). The dissimilarities between collembolan community compositions at 1 or 5 m from roadsides as compared to those of reference sites 20 m from roadsides appeared to be attributable to higher density losses of all species found at 1 or 5 m. Distance-based linear modeling showed that the collembolan community composition was associated both with distance from the forest edge and with the index values of tree community structure. Folsomia octoculata served as an inner-forest (≥20 m from the roadside) indicator species. The prevalences of certain dominant species were correlated with the first tree nonmetric multidimensional scaling (NMDS) axis. Overall, changes in collembolan communities at forest edges seemed to be caused by diminished soil water content and the presence of tree communities that differed from those in deeper forest.

Sustainability of forest bioenergy in Europe: land‐use‐related carbon dioxide emissions of forest harvest residues

AbstractIncreasing bioenergy production from forest harvest residues decreases litter input to the soil and can thus reduce the carbon stock and sink of forests. This effect may negate greenhouse gas savings obtained by using bioenergy. We used a spatially explicit modelling framework to assess the reduction in the forest litter and soil carbon stocks across Europe, assuming that a sustainable potential of bioenergy from forest harvest residues is taken into use. The forest harvest residue removal reduced the carbon stocks of litter and soil on average by 3% over the period from 2016 to 2100. The reduction was small compared to the size of the carbon stocks but significant in comparison to the amount of energy produced from the residues. As a result of these land‐use‐related emissions, bioenergy production from forest harvest residues would need to be continued for 60–80 years to achieve a 60% carbon dioxide (CO2) emission reduction in heat and power generation compared to the fossil fuels it replaces in most European countries. The emission reductions achieved and their timings varied among countries because of differences in the litter and soil carbon loss. Our results show that extending the current sustainability requirements for bioliquids and biofuels to solid bioenergy does not guarantee efficient reductions in greenhouse gas emissions in the short‐term. In the longer‐term, bioenergy from forest harvest residues may pave the way to low‐emission energy systems.

Effects of simulated increased grazing on carbon allocation patterns in a high arctic mire

Herbivory is an important part of most ecosystems, and grazing alone can have a considerable impact on the ecosystems carbon balance with both direct and indirect effects. Removal of above-ground biomass by consumption of herbivores will change the below-ground carbon stock; the reduction of litter that goes into the ground will influence the total ecosystem carbon content. Little is however known about how plant-herbivory interactions effect the carbon balance, in particular methane emissions, of high arctic mires. We hypothesized that increased grazing pressure will change carbon allocation patterns resulting in decreased net ecosystem uptake of carbon and subsequently in lower methane emissions. An in-situ field experiment was conducted over 3 years in a high arctic mire at Zackenberg in NE Greenland. The experiment consisted of three treatments, with five replicates of each (1) control, (2) vascular plants were removed (NV), (3) clipped twice each growing season in order to simulate increased muskox grazing. Immediately after the initiation of the experiment net ecosystem uptake of CO2 decreased in clipped plots (mean total decrease for the three following years was 35 %). One year into the experiment a significantly lower CH4 emission was observed in these plots, the total mean reduction for the following 2 years was 26 %. Three years into the experiment significantly lower substrate (acetic acid) availability for CH4 production was observed (27 % reduction). NV plots had a mean decrease in CO2 uptake of 113 %, a 62 % decrease in ecosystem respiration and an 84 % decrease in CH4 emission (mean of all 3 years). Our study shows that increased grazing pressure in a high arctic mire can lead to significant changes in the carbon balance, with lower CO2 uptake leading to lower production of substrate for CH4 formation and in lower CH4 emission.

STREET LITTER REDUCTION PROGRAMS IN THE NETHERLANDS: REFLECTIONS ON THE IMPLEMENTATION OF THE DUTCH LITTER REDUCTION PROGRAM FOR 2007 - 2009. LESSONS FROM A PUBLIC PRIVATE PARTNERSHIP IN ENVIRONMENTAL POLICY

On a daily basis one is confronted with litter. Most forms of litter are, however, of no concern to people. Nonetheless, litter accounts for serious economic costs, and causes negative effects to health, safety and biodiversity. Most countries implement litter reduction policy programs, often in the form of litter collection and penalties for littering. Litter reduction does not necessarily have to be a government initiative as grassroots and business initiatives have shown; for instance, citizens may adopt a road to collect litter, or to prevent others from littering. In this paper we focus on a comprehensive three year €48 Million litter reduction program which was set up in the Netherlands, by a consortium that involved actors from both the public and private sectors. The aim of this paper is to reflect on the design and implementation of this program. The key results are that although the program was not directly effective in meeting predetermined policy goals in terms of observed litter reductions, the program did succeed in laying the foundations on which future programs can prosper. Tensions between public and private actors in the program consortium led to delays and setbacks, but in the end most struggles were overcome, in large part to a mutual learning process. Our case is useful for policymakers and academic scholars seeking to learn from policy practices in waste management, and public-private partnerships for environmental programs.

Carbon stocks in fynbos, pastures and vineyards on the Agulhas Plain, South Africa: a preliminary assessment

Large tracts of fynbos on the Agulhas Plain are being converted to agriculture. Carbon (C) stocks in fynbos, pastures and vineyards were measured in this preliminary study to determine whether conservation of fynbos results in greater C storage relative to agricultural land uses. Fynbos had greater aboveground C than pastures (12.7 ± 1.7 vs 0.8 ± 0.3 t C ha−1), greater root C than pastures and vineyards (13.0 ± 11.7, 4.9 ± 1.4 and 0.2 ± 0.2 t C ha−1, respectively), less soil organic C than pastures (1.26 ± 0.14 vs 2.06 ± 0.22%) and less total soil C than pastures (66.7 ± 7.2 vs 99.2 ± 10.9 t C ha−1). The results indicate that conversion of fynbos into pastures is unlikely to result in a net loss of C stocks because reductions in aboveground biomass, litter and root C are recovered through gains in soil C. Conversion of fynbos into vineyards is likely to result in a net loss of approximately 23 t C ha−1 in aboveground and root biomass.

Herbaceous Plants and Grasses in a Mountain Longleaf Pine Forest Undergoing Restoration: A Survey and Comparative Study

The Berry College Longleaf Pine Management Area consists of old-growth fire-suppressed mountain Pinus palustris (Longleaf Pine) stands embedded within an encroaching matrix of mixed pines and hardwoods. Since 2001, portions of this area have been subjected to restoration efforts involving logging followed by burning, foliar herbicide application, and planting, as well as burning and hardwood control using herbicides in unlogged old-growth stands. To document the herbaceous plants and grasses of this site and to begin to address questions concerning the short-term impacts of management practices on these species, flowering specimens were systematically collected in managed and unmanaged stands in 2008 and 2009. We recorded 201 species in 35 families, including 70 species of Asteraceae, 35 species of Poaceae, 17 species of Fabaceae, and 10 grass-like species other than Poaceae (Cyperaceae, Iridaceae, and Juncaceae). Native herbaceous plants most commonly found included: Houstonia caerulea, Hypoxis hirsuta, Solidago odora, Oxalis stricta, Coreopsis major, Hypericum hypericoides, Lespedeza procumbens, Hieracium venosum, and Packera paupercula. While only 14 species were found in unmanaged old growth, 127 were found in managed old growth, and 167 in logged areas. Fire suppressed old-growth mountain Longleaf Pine forests are generally virtually devoid of understory plant diversity; these results suggest that reduction in canopy density and leaf litter can substantially recover herbaceous and grass species diversity. However, the extent to which understory diversity can be fully recovered in any specific site remains in question, particularly if local propagule sources have vanished during the period of fire suppression. A comparison with historical species lists at our site, and with other mountain Longleaf Pine forests in various stages of fire maintenance, is presented to help define characteristic understory species for mountain Longleaf Pine forests.

Amelioration of the periparturient relaxation of immunity to parasites through a reduction in mammalian reproductive effort

The degree of periparturient relaxation of immunity to gastrointestinal parasites has a nutritional basis, as overcoming protein scarcity through increased protein supply improves lactational performance, enhances local immune responses and reduces worm burdens. Herein lactating rats, re-infected with Nippostrongylus brasiliensis, are used to test the hypothesis that a similar and rapid improvement of immunity can be achieved through reducing nutrient demand at times of dietary protein scarcity. Reducing litter size from 12 to three pups during lactation resulted, as expected, in cessation of maternal body weight loss and increased pup body weight gain compared with dams which continued to nurse 12 pups. This increase in performance concurred with a rapid decrease in parasitism; within 3days post nutrient reduction, a 87% reduction in the number of worm eggs found in the colon and 83% reduction in worm burdens was observed, which concurred with increased local immune responses, i.e. 70% more mast cells and 44% more eosinophils in the small intestinal mucosa, to levels similar to those in dams nursing three pups throughout. However, there were no concurrent changes in goblet cell hyperplasia, serum anti-N. brasiliensis-specific antibody levels or mRNA expression of IL-4, IL-10 or IL-13 in the mesenteric lymph nodes. To our knowledge the current study is the first to employ a litter reduction strategy to assess the rate of immune improvement upon overcoming nutrient scarcity in a non-ruminant host. These data support the hypothesis that periparturient relaxation of immunity to gastrointestinal nematodes can be reduced by restoring nutrient adequacy and, importantly, that this improvement can occur very rapidly.

Safety evaluation of commonly used Chinese herbal medicines during pregnancy in mice

It is unclear how safe the use of Chinese herbal medicine is during pregnancy and if the herbal medicines do any harm to pregnancy, embryo-fetal development and prenatal and post-natal growth. A large-scale preclinical study was conducted to detect the adverse effects of Chinese herbal medicines during pregnancy. Twenty of the most commonly used Chinese herbal medicines prescribed for pregnancy were selected and the crude extract was administered to pregnant mice at clinical doses during five different gestational stages, namely post-implantation, gastrulation, organogenesis, maturation and whole gestation periods. Maternal effects on side effects, weight loss, litter reduction, implantation failure and fetal resorption and perinatal effects on growth restriction, developmental delay, congenital malformations and post-natal mortality were determined. Adverse pregnancy outcomes were commonly observed after maternal exposure to the herbal medicines, particularly during early pregnancy. Major events included maternal and perinatal mortality were recorded. Maternal weight gain, embryo growth and post-natal weight gain were significantly decreased. Fetal resorption and skeletal malformations were significantly increased. Reproductive toxicity of Chinese herbal medicines commonly used during pregnancy was identified in mice. Caution should be taken in the clinical use of herbal medicines during pregnancy.

Seed and microsite limitation in a late-successional old field: the effects of water, adults, litter, and small mammals on seeds and seedlings

Many plant communities are recruitment limited, which may occur because there are either too few seeds to fill available microsites, too few available microsites, or both. In a recruitment-limited, Minnesota, USA old field, we tested among these alternatives in a three-phase study. In phase 1, we estimated the production of late-successional forb and C4 grass seeds. In phase 2, we experimentally modified field establishment conditions with rainfall amendment, adult plant thinning, litter reduction, and small mammal exclusion. We then measured recruitment. On average, of the nearly 2,600 seeds produced m−2, only 164 seeds m−2 were present and living after overwintering, as measured by field and greenhouse germination. Furthermore, on average, only 9 of those 164 seeds m−2 germinated in the field, even under the relaxed establishment conditions of our four experimental treatments. Although adults of C4 grasses dominate the field, surprisingly few C4 grass seedlings germinated. To understand why, in phase 3, we added seed of the three dominant C4 grasses into the same plots the following year. Their ability to recruit into control plots compared with treated plots was relatively lower than for the ambiently recruited forbs from phase 2, suggesting that the competitively dominant C4 grasses have greater difficulty establishing in the extant community. Of the seeds that did germinate in the field in phases 2 and 3, all four experimental treatments significantly improved at least one stage of establishment, with the rainfall amendment having the greatest overall effect across species. In total, our results suggest that seed limitation was exacerbated by microsite limitation via multiple mechanisms.

Litter reductions reveal a trade-off between offspring size and number in brown bears

Experimental manipulations have revealed positive effects of litter reduction on offspring mass in small mammals, but little is known about this trade-off in large mammals. We examined the determinants of natural litter size variation and quantified the effects of litter size, maternal characteristics, and litter composition on yearling mass using 24 years of data on marked brown bears (Ursus arctos) in Sweden. Infanticide by adult males is a major cause of cub-of-the-year mortality, leading to litter size reductions. Litter size (n = 265) at den emergence ranged from one to four cubs (average, 2.7) and increased with maternal age. Litter size, however, appeared independent of maternal size, population density, interlitter interval, study area, or previous litter sex ratio. Yearling body mass increased with maternal body size but was independent of litter sex ratio. Litter size and yearling mass were negatively correlated, mostly because singletons were about 30 % heavier than yearlings from litters of two to four cubs. In reduced litters, survivors were on average 8 % heavier as yearlings than individuals from intact litters, suggesting that sibling competition reduces growth. Trade-offs between litter size and yearling mass in bears appear similar in magnitude to those found in small mammals.

Commentary on the Role of Maternal Toxicity on Developmental Toxicity

Maternal mammalian toxicity impacts prenatal development, with general systemic maternal toxicity, from reduced weight gain to morbidity, causative for reduced fetal weights/litter and increased fetal variations (especially skeletal)/litter, but not, in the author's opinion, for increased fetal malformations, reduced litter sizes or full litter losses. Increased fetal malformations are likely due to exposure to specific chemicals which alter specific maternal functions at critical point(s) in pregnancy, typically exaggerated effects from higher doses by drugs under development with known, desired pharmacological effects. Malformations can also be from genetic/epigenetic alterations, specific altered proteins, molecular pathways, etc. Full litter losses are triggered by the mother and are rare in rats. Information to inform maternal (and developmental) toxicity includes ovarian corpora lutea counts, uterine implantation profile, degree of litter reduction (if present), timing and extent of maternal toxicity relative to those of adverse embryofetal effects, etc. The view of maternal toxicity as confounding results in in vivo developmental toxicity studies, worldwide concerns about increased research animal usage, increasing time, labor, costs, and new software and hardware sophistication all drive the interest in development, validation, and performance of in vitro/in silico assays. These assays are fast, inexpensive, responsive to animal use concerns and amenable to mechanistic questions. The strength of these in vitro/in silico assays is considered by many to be the absence of the maternal organism/placenta. These assays inform mechanism and hazard, but NOT risk. The Environmental Protection Agency currently estimates that these new assays are approximately 70% accurate versus the whole animal tests.

Achieving Smoke-free Apartment Outdoor Area Policies in Asian/Pacific Islander Neighborhoods of Central Los Angeles

Attempting to achieve non-smoking outdoor area policies in apartment complexes of Central Los Angeles Asian/Pacific Islander neighborhoods, People's CORE, a community based organization, partnered with a professional evaluator for a three year campaign. Focus group discussion results with residents showed readiness as well as hesitation towards non-smoking policies. Through community organizing, focus group discussions with tenants and one-on-one education outreach activities to apartment managers, the organization managed to have 20 apartment complexes adopt and implement policies for smoking restrictions in their common outdoor areas. Pre- and post observations at 52 apartment complexes showed statistically significant reduction of tobacco litter in parking areas/garages, entrance ways, courtyards, and balcony/walkway/community rooms. The authors attribute the success of the project in part to the long-standing good reputation of People's CORE as a community mobilizer and organizer.

High nitrogen deposition alters the decomposition of bog plant litter and reduces carbon accumulation

AbstractBogs are globally important sinks of atmospheric carbon (C) due to the accumulation of partially decomposed litter that forms peat. Because bogs receive their nutrients from the atmosphere, the world‐wide increase of nitrogen (N) deposition is expected to affect litter decomposition and, ultimately, the rate of C accumulation. However, the mechanism of such biogeochemical alteration remains unclear and quantification of the effect of N addition on litter accumulation has yet to be done. Here, we show that 7 years of N addition to a bog decreased the C : N ratio, increased the bacterial biomass and stimulated the activity of hydrolytic and oxidative enzymes in surface peat. Furthermore, N addition modified nutrient limitation of microbes during litter decomposition so that phosphorus became a primary limiting nutrient. Alteration of N release from decomposing litter affected bog water chemistry and the competitive balance between peat‐forming mosses and vascular plants. We estimate that deposition of about 4 g N m−2 yr−1 will cause a mean annual reduction of fresh litter C accumulation of about 40 g m−2 primarily as a consequence of decreased litter production from peat‐forming mosses. Our findings show that N deposition interacts with both above and below ground components of biodiversity to threaten the ability of bogs to act as N‐sinks, which may offset the positive effects of N on C accumulation seen in other ecosystems.