Litter

Structural information on soil organic matter (SOM) at the molecular level can be obtained on diverse structural units that are amenable to degradation techniques. Chemolytic techniques in combination with colorimetric analyses or GC MS are used to determine amino acids (proteins), sugars (polysaccharides), lipids, or aromatic oxidation products from lignin or charred organic matter. Microbial markers (amino sugars, muramic acid) are analyzed after hydrolysis and gas chromatographic separation. Macromolecular structures can also be subjected to thermochemolytic degradation or pyrolysis and subsequent analysis of the fragments by GC MS. Alternative techniques for the examination of organic matter in heterogeneous macromolecular mixtures are non-destructive spectroscopic methods, such as nuclear magnetic resonance (NMR) spectroscopy. Although this technique can give good results concerning the gross chemical composition, speci®c compounds are hardly identi®ed. The combination of spectroscopic techniques with thermolytic and chemolytic methods will add substantially to the understanding of the nature of refractory soil organic matter. Physical fractionation prior to analysis provides a means to dierentiate between distinct SOM pools that can be further characterized by the methods described above. Studies on SOM structural characteristics have focused mainly on the A horizons of soils under agriculture and litter biodegradation in forest soils and need to be extended to a wider variety of soil types and the subsoil. #

Purely observational studies have documented differences in the abundance and diversity of several litterdwelling arthropods between sites adjacent to, and far from, CWD, which suggests that reduction of fallen coarse woody debris (CWD) in temperate forests by traditional forestry practices may affect the litter arthropod community. As few field experiments have directly tested the impact of CWD on arthropods inhabiting the litter at different distances from CWD, we removed CWD from replicated open plots on the floor of a second-growth deciduous forest in order to reveal the causal connection between CWD and litter-dwelling spiders, often the most diverse and abundant predators among the litter macrofauna of temperate forests. We also documented the impact of the CWD manipulation on spider prey and several other major macroarthropod groups. Before removing CWD (∅ = 14.3 ± 0.7 cm), we measured response variables as a function of distance (0.5-1.5 m) from CWD in both removal and control plots. In agreement with results of previous research that solely utilized this observational approach in temperate forests, volume and dry mass of litter, spider diversity, overall spider density, and densities of 8 of 16 major spider genera were higher adjacent to CWD before experimental manipulations. Removing CWD reduced the amount of litter and the density of spiders in litter close to where the CWD had been. Removing CWD also altered spider community structure, which had differed between litter sites adjacent to, and far from, CWD prior to the experimental removal of CWD. The patterns, though, were not completely congruent, as some of the taxa affected by the manipulation had not differed between sites prior to the removal of CWD, and vice-versa. Our findings suggest that complex interactions among structural, biotic and microclimatic factors underlie the observed responses to CWD removal by spiders and other arthropods in the litter layer. We also conclude that drawing inferences solely from observational studies is not a reliable approach for predicting the impact of changes in the amount of CWD on arthropods of forestfloor leaf litter. Further field experiments manipulating different volumes of CWD are needed in order to determine the minimum amount of CWD that should be kept on the forest floor of managed forests in order to maintain densities and diversities of major leaf-litter arthropods.

Perennial grasslands that dominated the southwest United States during the past 10,000 years have been desertified to varying extents. Desertification is a temporal phenomenon, defined in this paper as a change in the scale of the spatial distribution of resources. We report here on several indicators of desertification, using bare patch indices as surrogates for direct measures. A bare patch index based on canopy cover, which is relevant for precipitation and wind-driven erosion, is not equivalent to another bare patch index based on soil surface measurements, which is relevant for overland water flowdriven erosion. Per cent grass cover, per cent long-lived grass cover, per cent cover of vegetative reproducers, and a relative preference index all yielded sensitive indicators of desertification. The usefulness of some indicators, such as organic litter, depends upon recent environmental history. Other indicators, such as per cent cover due to grazing-resistant species, appear not to be sensitive to desertification and need further development. Range site type may also be important in determining indicator responses, where some indicators were sensitive to a range site while others were not. Overall, we have identified several sensitive indicators of desertification based on vegetational characteristics in varied range sites in the northern Chihuahuan Desert.

refers to molecular-level characteristics such as elemental composition, functional groups, and molecular con-Formation of chemically resistant humic substances might be an formation that influence the inherent biodegradability important process controlling recycling of soil C to the atmosphere. of the molecule. Interactions refers to the intermolecular Humic substances are believed to be resistant to microbial decomposition because they accumulate in soil, but there is little direct experi-interactions with other inorganic or organic molecules mental evidence for their inherent recalcitrance. My objective was to that influence biodegradability-for example, complexcompare the microbial mineralization rates of the humic and fulvic ation with Al. Physical accessibility refers to the location acid fraction to other fractions of decayed plant matter in soil. Uniof the molecule with respect to enzymes or cells. For formly 14 C labeled Populus fremontii leaf litter that had decomposed example, substrates may be located in submicrometer for 180 d was fractionated into the NaOH-insoluble residue, phenolic, pores too small for microbial cells to enter (Sollins et humic acid, fulvic acid, hydrophilic acid, and hydrophilic neutral fracal., 1996). These conditions do not necessarily occur extions. Humic acid comprised 22.7% of the C in the decomposed litter.

The effect of litter on the abundance and community structure of soft-bottom epibenthic megafauna was investigated in three coves of the Saronikos Gulf (Aegean Sea). At each site, two surfaces were defined on the sea-bottom. One of the surfaces was uniformly littered with debris (16 items per 100 m 2 ), while the other remained 'clean' and acted as control. Benthic megafauna was censused with SCUBA diving, once before the littering episode and then monthly for one year. Both total abundance and the number of species showed an increasing trend in the impacted surfaces, either because the litter provided refuge or reproduction sites for mobile species or because hard-substratum sessile species had the opportunity to settle on provided surfaces. A marked gradual deviation in the community structure of the impacted surface from the control and a clear successional pattern of change in the community composition of the impacted surfaces were demonstrated.

1. We investigated the effect of moderate eutrophication on leaf litter decomposition and associated invertebrates in five reference and five eutrophied streams in central Portugal. Fungal parameters and litter N and P dynamics were followed in one pair of streams. Benthic invertebrate parameters that are considered useful in bioassessment were estimated in all streams. Finally, we evaluated the utility of decomposition as a tool to assess stream ecosystem functional integrity.2. Decomposition of alder and oak leaves in coarse mesh bags was on average 2.3–2.7× faster in eutrophied than in reference streams. This was attributed to stimulation of fungal activity (fungal biomass accrual and sporulation of aquatic hyphomycetes) by dissolved nutrients. These effects were more pronounced for oak litter (lower quality substrate) than alder. N content of leaf litter did not differ between stream types, while P accrual was higher in the eutrophied than in the reference stream. Total invertebrate abundances and richness associated with oak litter, but not with alder, were higher in eutrophied streams.3. We found only positive correlations between stream nutrients (DIN and SRP) and leaf litter decomposition rates in both fine and coarse mesh bags, associated sporulation rates of aquatic hyphomycetes and, in some cases, total invertebrate abundances and richness.4. Some metrics based on benthic invertebrate community data (e.g. % shredders, % shredder taxa) were significantly lower in eutrophied than in reference streams, whereas the IBMWP index that is specifically designed for the Iberian peninsula classified all 10 streams in the highest possible class as having ‘very good’ ecological conditions.5. Leaf litter decomposition was sufficiently sensitive to respond to low levels of eutrophication and could be a useful functional measure to complement assessment programmes based on structural parameters.

The study creates awareness among farmers and common man towards clean environment in their 9 surroundings through decomposition of organic waste in to valuable manure using Eisenia fetida. The investigation was destined to produce vermicompost from neem leaves litter and cow dung in plastic tubs kept in screen house. The nutrient status of vermicompost was evaluated on initial, 45th and 90th day. Total organic carbon (3.76%), carbon/nitrogen ratio (2.73%) decreased whereas nitrogen (1.38%), phosphorus (0.27%) and potassium (0.21%) content increased on 90th days. The organic waste like neem leaves litter can be used for sustainable agriculture by converting them in to vermicompost.

Disturbance may be an important determinant of plant community composition and diversity owing to its effects on competitive interactions, resources, dominance and vigour. The effect of type, timing and frequency of disturbance on grass and forb species richness was examined using data from a long-term (> 50 yr) grassland burning and mowing experiment in KwaZulu-Natal, South Africa.

For two decades, solid waste components in Bank projects have focused on collection of solid wastes, with equipment provided to upgrade operations at existing open dumps. Since early 1990, the private sector has become increasingly involved in the collection, disposal, and treatment of solid waste, and Bank projects have placed greater priority on implementation of new sanitary landfills. The following guidance provides an examination of some of the issues which need to be addressed in landfill siting and design.

Several leaf litter decay studies have indicated that decomposition occurs more rapidly when litter is placed beneath the plant species from which it had been derived than beneath a different plant species (i.e. home-field advantage, HFA), although support for this notion has not been universal. We provide the first quantification of HFA in relation to leaf litter decomposition using published litter mass loss data from forest ecosystems in North America, South America, and Europe. Our findings indicate that HFA is widespread in forest ecosystems; on average litter mass loss was 8% faster at home than away. We hypothesize that HFA results from specialization of the soil biotic community in decomposing litter derived from the plant above it. Climate and initial litter quality data can be used to explain about 70% of the variability in litter decomposition at a global scale, leaving about 30% unexplained. We suggest that HFA be recognized as a factor that explains some of this remaining variability.

Amazonian forest fragments and secondgrowth forests often differ substantially from undisturbed forests in their microclimate, plant-species composition, and soil fauna. To determine if these changes could affect litter decomposition, we quantified the mass loss of two contrasting leaf-litter mixtures, in the presence or absence of soil macroinvertebrates, and in three forest habitats. Leaf-litter decomposition rates in second-growth forests (>10 years old) and in fragment edges (<100 m from the edge) did not differ from that in the forest interior (>250 m from the edges of primary forests). In all three habitats, experimental exclusion of soil invertebrates resulted in slower decomposition rates. Faunal-exclosure effects were stronger for litter of the primary forest, composed mostly of leaves of old-growth trees, than for litter of second-growth forests, which was dominated by leaves of successional species. The latter had a significantly lower initial concentration of N, higher C:N and lignin:N ratios, and decomposed at a slower rate than did litter from forest interiors. Our results indicate that land-cover changes in Amazonia affect decomposition mainly through changes in plant species composition, which in turn affect litter quality. Similar effects may occur on fragment edges, particularly on very disturbed edges, where successional trees become dominant. The drier microclimatic conditions in fragment edges and second-growth forests (>10 years old) did not appear to inhibit decomposition. Finally, although soil invertebrates play a key role in leaf-litter decomposition, we found no evidence that differences in the abundance, species richness, or species composition of invertebrates between disturbed and undisturbed forests significantly altered decomposition rates.

Surface (0-15 cm) and subsurface (30-45 cm) soil samples from under canopy, edge of canopy and away from canopy of isolated Cordia africana Lam. and Croton macrostachyus Del. trees and their leaves were examined to investigate leaf nutrient content, root biomass and the contribution of trees on farms to soil fertility parameters in Badessa area, eastern Ethiopia. Leaves of C. macrostachyus had 20% higher P and 25% lower K contents than those of C. africana. The studied species had comparable leaf N content. Both species produced shallow lateral roots that extended beyond the canopy zone. Typically, higher fine root biomass was observed in the surface soils than the subsurface soils. Both species did not affect soil organic C, pH and cation exchange capacity. Surface and subsurface soils under tree canopies had 22-26 and 12-17% higher N, respectively, than the corresponding soils away from tree canopies. Surface soil available P under tree canopies was 34-50% higher than the corresponding soil away from canopies. Available P content of subsurface soil was im-proved only under C. africana canopy. The available P of surface soil under C. macrostachyus canopy was more than double that for C. africana. Trees of both species increased underneath surface and subsurface exchangeable K by 18-46% compared with the corresponding controls. In conclusion, C. macrostachyus and C. africana trees on farms keep soil nutrient high via protection against leaching, translocation of nutrients from deeper to the surface layer and accumulation of litter, which create a temporary nutrient pool in the surface soils under their canopies.

The feeding preferences and consumption rates of the exotic woodlouse Armadillidium vulgare were measured on litters from the autochthonous Rio Grande cottonwood and the exotic Russian olive. When offered a choice between five litter types (green and shed leaves of Russian olive and cottonwood, and fruits of Russian olive), the isopods consumed more of the exotic plant litter (green leaves and the fruits of Russian olive) than of the autochthonous cottonwood. When offered only one diet, consumption rates of green leaves and fruits of Russian olive were again the highest. Feeding was related with N and C:N ratios of the litter, with highest consumption of diets with low and high C:N ratios and lowest consumption of diets with intermediate C:N ratios. The N content was highest (and C:N ratios lowest) on isopods feeding shed leaves of Russian olive. Growth was not related to the amount or the C:N ratio of the food consumed, being highest for animals feeding on shed leaves of cottonwood. Our results show that the consumption patterns and the C and N body composition of the exotic woodlouse A. vulgare are altered when fed with Russian olive litter, suggesting that the replacement of the autochthonous cottonwood by the exotic Russian olive may negatively affect the maintenance of the population of these exotic detritivores in the area.

For two decades, solid waste components in World Bank projects have focused on collection of solid wastes, with equipment provided to upgrade operations at existing open dumps. Since early 1990, the private sector has become increasingly being involved in the collection, disposal, and treatment of solid waste and World Bank projects have placed greater priority on implementation of new sanitary landfills. The following guidance provides an examination of some of the issues which need to be addressed in landfill siting and design.

Uso de cal virgem para o controle de Salmonella spp. e Clostridium spp. em camas de aviário Quicklime for controlling Salmonella spp. and Clostridium spp in litter from floor pens of broilers RESUMO O objetivo deste trabalho foi avaliar a eficácia do uso de cal virgem (CaO) para a redução de Salmonella spp. e Clostridium spp. em cama de aviário. Foram aplicados quatro tratamentos: T1-sem adição de cal virgem (controle), T2aplicação de cal virgem na dose de 300g m -2 , T3-aplicação de cal virgem na dose de 600g m -2 e T4-aplicação de cal virgem na dose de 900g m -2 . Os valores médios observados para o pH da cama após o 12 o dia de aplicação de cal virgem foram 8,95 e 9,91, 10,75 e 11,11 para os tratamentos 1, 2, 3 e 4, respectivamente. O número mais provável Log 10 (UFC) de Salmonella spp. e Clostridium spp foi reduzido em 82 e 97% com a aplicação de cal na dosagem de 300g m -2 e 100% na dosagem de 600 e 900g m -2 , ambos diferindo significativamente em relação ao controle (antes da aplicação da cal). A atividade de água da cama reduziu progressivamente (de 0,2 a 3,82%) com a utilização de níveis crescentes de cal. Conclui-se que o uso da cal na cama de aviário, mesmo nas doses mais baixas, reduz o número mais provável de Salmonella e Clostridium ssp. Palavras-chave: bactérias, eficácia, redução, atividade de água. ABSTRACT This study aimed to evaluate the efficacy of quicklime (CaO) for reducing Salmonella and Clostridium spp. population in used litter from floor pens of broilers. Four treatments were tested: (T1) control (without quicklime); (T2) 300g quicklime m -2 ; (T3) 600g quicklime m -2 ; and (T4) 900g quicklime m -2 . The following average pH values were observed 12 days after adding quicklime: 8.95, 9.91, 10.75 and 11.11 for treatments 1, 2, 3 and 4, respectively. An 82 and 97% reduction in the most probable number Log 10 (CFU) of Salmonella and Clostridium spp, respectively, was observed when 300g m -2 of quicklime was added to the used litter from floor pens of broilers. Additionally, a 100% reduction was obtained when both 600 and 900g m -2 of quicklime were added, differing significantly from control (before adding quicklime). A progressive reduction in water activity (from 0.2 to 3.82%) was observed when growing levels of quicklime were used. In conclusion, even the lowest level of quicklime added to litter from floor pens of broilers reduces the most probable number of Salmonella and Clostridium spp

A new culture method for lesser mealworm, Alphitobius diaperinus (Panzer), was developed to provide large numbers of adult lesser mealworms of approximately the same age for insecticide resistance testing. Culturing entailed allowing 100 adults to reproduce for 4 days in a wheat-based culture medium contained inside a plastic culture box, removing the adults from the medium, and then rearing their progeny to adulthood therein, in approximately 56 days at 32°C and 55% RH. During their development, progeny were supplied water via apple slices at 0, 21 and 35 days, and a foam substrate in which to pupate, also at 35 days. During 2004-2005, adult lesser mealworms were collected from six broiler-house populations and then cultured with this method. Each population produced 4500 adults required to complete resistance testing with one insecticide within ten culture boxes, at an average of 798 adults per culture box.

Litterbag experiments with 10 different kinds of leaf litter showed that detritivore (Lumbricus species) and geophagous (Aporrectodea species) earthworms prefer certain litter types over others, since different numbers of worms were found below the litter after 50–52 days of ...

In laboratory microcosms, we investigated the influence of diversity of both leaf litter and detritivores on decomposition processes. Either woodlice or earthworms, or a combination of woodlice and earthworms, fed on leaf litter of either oak or alder, or oak and alder for 8 weeks. Mass loss of leaf litter, soil microbial respiration and soil nutrient concentrations were determined every 2 weeks. 2 . For four out of seven decomposition parameters, the joint effects of woodlice and earthworms were stronger than the sum of single-species effects when they had fed on alder litter. When feeding on oak litter, however, woodlice and earthworms together revealed lower decomposition rates than predicted from their single effects. Joint effects of detritivores on decomposition of mixed litter were always lower than predicted from the sum of their effects. 3. In mixed-litter assays, we obtained intermediate values of decomposition parameters, indicating that doubling the species richness of leaf litter from one to two species did not promote decomposition processes. Effects of mixing litter were, thus, mostly additive; essentially only when earthworms fed on mixed litter we observed, mostly positive, non-additive effects of diverse litter. 4 . Our findings provide evidence for a potential effect on ecosystem functioning through joint action of detritivores even at low species diversity, while litter diversity seems to be less significant. On high-quality litter, isopods and earthworms are not functionally redundant but act synergistically on litter decomposition. The effects of detritivore diversity on ecosystem processes, however, are context-specific and depend on the quality and diversity of the available food sources, and on species-specific characteristics of the detritivores.

The moment the soil enters into contact with an earthworm, both superficially and intemally, physicochemical and biological changes take place. The drilosphere represents the whole soil volume under earthworm influence. Thus it includes the body surfaces, the gut and all the internal features of the worm that are in contact with the ingested soil, as well as the external structures (casts, burrows, middens) created by earthworm activities. The extent of the drilosphere and its particular characteristics depend on the species and ecological categories of the earthworm community present as well as the spatial and temporal scale of interest. Spatially, the drilosphere can interact with other soil functional domains and lead to significant changes in the litter system or detritusphere (generally decreasing litter stocks) and the rhizosphere (affecting both root biomass and density), the two main sources of organic matter (OM) additions to the soil, as well as in the aggregatusphere and the porosphere. Drilosphere effects on microbial activity and OM decomposition can be completely different (and opposite) depending on the spatio-temporal scale of observation. At the level of the gut, microbial activity is dramatically stimulated in a matter of a few hours via a mutualistic digestion system. In this process, water and soluble-C in the form of intestinal mucus (the Kiss) produced by the earthworm (Prince Charming) awakens the dormant microflora (Sleeping Beauties), thereby increasing decomposition of the stable forms of soil OM ingested. During gut passage populations of other organisms (e.g. protozoa, nematodes, fungi) may decline with digestion, although these organisms probably form a minor component of the earthworm's energy needs. In the casts and on the burrow walls, the abundant nutrient resources for soil microflora continue the priming effect of the gut, increasing over a short time period mineralization rates and plant nutrient bio-availability. However as castings, particularly of the 'compacting group', and burrow walls begin to dry and stabilize with age (days to weeks), OM decomposition, nutrient mineralization and microbial activity decrease, often reaching levels lower than uningested soil due to 'protection'. Finally at the scale of years to decades and soil profile, it,appears that the drilosphere can exert an important regulation on OM incorporation and tumover rates, and soil C stocks. O 2000 Editions scientifiques et médicales Elsevier SAS I ~~~~~~~~~~

Inadequate boron (B) nutrition can affect the structural integrity and chemical composition of plant tissues. The changes in mass and element concentrations were studied using silver birch (Betula pendula Roth) leaf litter from seedlings grown with or without added B (B litter + or B litter −). The litter was produced in a growth room, and it was incubated in either B fertilised or control forest plots (B soil + or B soil −) between the moss and humus layers in two Norway spruce stands for 13 months. Additionally, the field decomposition experiment included longterm N and P application treatments (N soil and P soil ). B litter + somewhat reduced the remaining litter mass. In contrast, B soil + increased it, possibly because of lower soil pH. The +N soil treatment reduced the remaining mass. B litter + increased the remaining P, S, Cu, Cd, Ni and Zn but reduced Pb. Remaining B was high in the B litterwhich also accumulated B from soil. B soil increased remaining Ca, Cd, Mg, Na, Pb, and slightly reduced N (in N fertilised plots). These changes in decomposition and element release have a potential to affect nutrient, carbon, and heavymetal cycles in areas where B deficiencies are common, and where B fertilisation is practised.

The abundance, nature and possible sources of litter on 32 beaches on the Balearic Islands (Mediterranean Sea) were investigated in 2005. Mean summer abundances in the Balearics reached approximately 36 items m -1 , with a corresponding weight of 32±25 g m -1 , which is comparable to the results of other studies in the Mediterranean. Multivariate analyses (principal component analysis and redundancy analysis) confirmed strong similarities between islands and a statistically significant seasonal evolution of litter composition and abundance. In summer (the high tourist season), debris contamination expressed as item abundance was double that in the low season and showed a heterogeneous nature associated with beach use. Cigarette butts were the most abundant item, accounting for up to 46% of the objects observed in the high tourist season. In contrast, plastics related to personal hygiene/medical items were predominant in wintertime (67%) and natural wood was the most important debris by weight (75%). In both seasons, litter characteristics suggested a strong relationship with local land-based origins. While beach users were the main source of summer debris, low tourist season litter was primarily attributed to drainage and outfall systems.

This paper investigates the use of charges and standards in dealing with a common externality, plastic litter from shopping bags in Botswana. The country passed a plastic bag legislation (effective 2007) to curb the plastic bag demand. Uniquely, the act does not stipulate the amount that the retailers had to charge for plastic bags, they, independently from one another, set different prices. We assessed the environmental effectiveness and efficiency of the plastic bag legislation by analysing consumers' sensitivity to the improvement of the plastic bag and related price charges.

s Abstract Plant species differ in how they influence many aspects of ecosystem structure and function, including soil characteristics, geomorphology, biogeochemistry, regional climate, and the activity and distribution of other organisms. Attempts to generalize plant species effects on ecosystems have focused on single traits or suites of traits that strongly covary (functional groups). However, plant effects on any ecosystem process are mediated by multiple traits, and many of these traits vary independently from one another. Thus, most species have unique combinations of traits that influence ecosystems, and there is no single trait or functional-group classification that can capture the effects of these multiple traits, or can predict the multiple functions performed by different plant species.

Tropical forest regeneration is hindered by human-induced fires. After deforestation by fires, Pteridium spp. (bracken fern) often colonizes and dominates the vegetation for long time periods, presumably inhibiting the succession. Tree species from mature forests are rare in the degraded areas, potentially due to the lack of seed dispersal and unfavourable abiotic conditions. Here, we experimentally assess the effect of bracken presence, in terms of litter and shade, on seedling recruitment of three native, shade-tolerant tree species in the tropical mountains of Bolivia. In a spatially blocked design at eight sites, we compared seedling recruitment, survival and growth three months and one year after sowing between experimental litter and vegetation treatments and among habitat types (forest interior, degraded habitats close and far from the edge) and species (Clusia sphaerocarpa, Clusia lechleri and Clusia trochiformis). We found that species differed in their recruitment success and habitat preferences, but responded similarly to experimental treatments. Litter removal increased temperature and reduced humidity on the ground and vegetation removal increased canopy openness. Seedling recruitment was consistently reduced by litter and vegetation removal, and their interaction had a deleterious negative effect. Seedling survival and growth were also reduced by litter removal. Our results highlight the overlooked facilitative effects of bracken by ameliorating harsh abiotic conditions and increasing the probability of Clusia seedling recruitment and potentially other shade-tolerant tree species in degraded habitats. To enhance forest regeneration in fire-degraded areas, we recommend spreading seeds of shade-tolerant tree species into the bracken vegetation. This method is less costly and might be more efficient than previous methods that involved repeated bracken removal. Recruitment of late-successional species in the bracken vegetation is likely to promote the restoration of tropical forest; however, longterm studies are needed to test the success of such efforts.

1. The aim of this study was to estimate the amount of leaf litter ingested by the shredder caddis-fly Sericostoma vittatum in a small stream in central Portugal. The study combined field data on population dynamics and laboratory experiments to determine the effect of temperature (9, 12, 15 and 18°C), leaf species (Alnus glutinosa, Castanea sativa, Populus · canadensis and Quercus andegavensis) and animal mass on growth and consumption rates of the larvae. 2. Sericostoma vittatum had two overlapping cohorts, each of which needed about 1 year to complete development. Mean annual density and biomass were 115 individuals m )2 and 83 mg m )2 , respectively. Secondary production was 0.44 g m )2 year )1 and production/ biomass ratio was 4.9-5 year )1 . 3. Consumption rates of larvae increased with temperature up to the optimal temperature for growth which varied between 13.7 and 16.7°C depending on the diet. 4. Consumption rate was positively related to larval mass but growth rate was negatively related with larval mass. Larvae fed on A. glutinosa and P. · canadensis had higher consumption and growth rates than those fed on C. sativa or Q. andegavensis. 5. Annual leaf litter consumption by S. vittatum was estimated as 14-22 g m )2 depending on the diet. No relationship was observed between the amount of detritus consumed by the population of this caddis-fly in the field and either water temperature, the stock of detritus on the stream bottom, or larval abundance. Instead, the temporal dynamics of leaf litter consumption by S. vittatum were controlled by its life history. 6. This study highlights the influence of factors such as animal size and water temperature on the invertebrate energetics. Models explaining how these variables affect invertebrate production efficiency may be very important for obtaining accurate estimates of the role of shredders in the energy flow across stream ecosystems.

Uso de cal virgem para o controle de Salmonella spp. e Clostridium spp. em camas de aviário Quicklime for controlling Salmonella spp. and Clostridium spp in litter from floor pens of broilers RESUMO O objetivo deste trabalho foi avaliar a eficácia do uso de cal virgem (CaO) para a redução de Salmonella spp. e Clostridium spp. em cama de aviário. Foram aplicados quatro tratamentos: T1-sem adição de cal virgem (controle), T2aplicação de cal virgem na dose de 300g m -2 , T3-aplicação de cal virgem na dose de 600g m -2 e T4-aplicação de cal virgem na dose de 900g m -2 . Os valores médios observados para o pH da cama após o 12 o dia de aplicação de cal virgem foram 8,95 e 9,91, 10,75 e 11,11 para os tratamentos 1, 2, 3 e 4, respectivamente. O número mais provável Log 10 (UFC) de Salmonella spp. e Clostridium spp foi reduzido em 82 e 97% com a aplicação de cal na dosagem de 300g m -2 e 100% na dosagem de 600 e 900g m -2 , ambos diferindo significativamente em relação ao controle (antes da aplicação da cal). A atividade de água da cama reduziu progressivamente (de 0,2 a 3,82%) com a utilização de níveis crescentes de cal. Conclui-se que o uso da cal na cama de aviário, mesmo nas doses mais baixas, reduz o número mais provável de Salmonella e Clostridium ssp. Palavras-chave: bactérias, eficácia, redução, atividade de água. ABSTRACT This study aimed to evaluate the efficacy of quicklime (CaO) for reducing Salmonella and Clostridium spp. population in used litter from floor pens of broilers. Four treatments were tested: (T1) control (without quicklime); (T2) 300g quicklime m -2 ; (T3) 600g quicklime m -2 ; and (T4) 900g quicklime m -2 . The following average pH values were observed 12 days after adding quicklime: 8.95, 9.91, 10.75 and 11.11 for treatments 1, 2, 3 and 4, respectively. An 82 and 97% reduction in the most probable number Log 10 (CFU) of Salmonella and Clostridium spp, respectively, was observed when 300g m -2 of quicklime was added to the used litter from floor pens of broilers. Additionally, a 100% reduction was obtained when both 600 and 900g m -2 of quicklime were added, differing significantly from control (before adding quicklime). A progressive reduction in water activity (from 0.2 to 3.82%) was observed when growing levels of quicklime were used. In conclusion, even the lowest level of quicklime added to litter from floor pens of broilers reduces the most probable number of Salmonella and Clostridium spp

The Primary productivity of a grassland commune
located at Kota of Bilaspur district, Chhattisgarh lies between
21 47’ to 23 _8’ North latitude and 81 _14’ to 83 _15’ East
longitude. A circular quadrate of 0.35 was used for
sampling the above ground plant parts. The size of quadrate was
determined by Species Area Curve Method. The grassland
community comprised of 17 species (8 were grasses and 9 were
non-grasses). Bothriochloa Pertusa,Cynodon dactylon, Digitaria
longiflora,  among the grasses and  Desmodium Triflorum,
Parthenium  and  Sida cordifolia  among the non-grasses were
found dominant during the study period. The annual grass
production was found to be 3502.67  /year. The non-grass
production showed maximum in the month of January
(128.20 ) and minimum in the month of June (1.95 ).
The annual non-grass production was found to be 782.87
/year. The study of primary productivity helps to recovery of the
natural ecosystems to the earlier balanced state and continuation
the biodiversity of grassland community in world.

Penelitian ini bertujuan untuk mengetahui pengaruh pemberian pakan differmentasi Acremonium charticola dan/atau antibiotik terhadap kualitas litter dan footpad dermatitis (FPD). Materi yang digunakan pada penelitian ini adalah 160 ekor day old chick (DOC) broiler jantan dengan bobot awal rata – rata 41,30 ± 2,68 g yang dipelihara selama 28 hari.  Kandang yang digunakan adalah kandang koloni berukuran 1 × 1 × 1,5 m dengan 20 unit petak percobaan. Pakan yang diberikan adalah pakan komersial BR dengan penambahan onggok yang diferementasi dengan A. charticola dan antibiotik neomycin, dengan perlakuan sebagai berikut : T0 (kontrol), T1 (kontrol + antibiotik), T2 (kontrol + onggok yang terfementasi dengan A. charticola + antibiotik) dan T3 (kontrol + onggok yang terfementasi dengan A. charticola).  Rancangan yang digunakan adalah rancangan acak lengkap (RAL) dengan 4 perlakuan dan 5 ulangan. Parameter yang diukur meliputi kualitas litter dan footpad dermatitis, selanjutnya data dianalisis keragamannya pada taraf ketelitian 5% dan 1%. Hasil penelitian menunjukkan bahwa tidak ada pengaruh nyata (P>0,05) pada kualitas litter tetapi berpengaruh nyata (P<0,01) pada footpad. Kesimpulan yang diperoleh yaitu penambahan onggok differmentasi A. charticola dan/atau antibiotik tidak merubah kualitas litter tapi berpengaruh terhadap footpad dermatitis.

Microorganisms Nematodes Setaria pasture a b s t r a c t Camponotus punctulatus builds big nests, up to 1.20 m high and 2 m in diameter, containing more organic matter and nutrients than the surrounding soil. The aim of this study was to relate litter decomposition in C. punctulatus nests with soil organisms. We expected a greater level of decomposition and more soil organisms within than outside the nests. The study site was a field of Setaria sphacelata, a common sown pasture in Northeastern Argentina, with 180 nests of C. punctulatus per hectare. To estimate decomposition rates we buried litterbags within and outside the nest (microsite type) at the beginning of each season and recovered those from the previous season. We used litterbags of different mesh size (7 mm, 2 mm, 100 mm and 1 mm) filled with 8 g of S. sphacelata litter. At the same time, we sampled the soil surrounding litterbags to estimate microbial dehydrogenase activity and the abundance of nematodes and mesofauna. Soil microbial activity was greater outside the nests, mesofauna were significantly more abundant inside the nests, and nematodes had similar abundance inside and outside the nests. Throughout all seasons, there was a greater proportion of Prostigmata and Mesostigmata in the nests, whereas Oribatida and Collembola were more abundant outside. Oribatid species composition differed between microsites. In the nests, there were two periods of higher decomposition (spring and summer) while outside the maximum occurred in spring, but only in litterbags of 7 and 2 mm mesh. The lack of macro and mesofauna (litterbags with 100-mm mesh) decreased organic matter decomposition in the nests in summer and induced phosphorus immobilization in winter. Ant activity and feeding preference, nest architecture and the plant community on C. punctulatus nests are suggested as plausible factors that modify soil organism abundance and decomposition.

The mass ratio hypothesis provides the key link between plant functional traits (PFTs) and ecosystem processes. Despite its centrality to the field it has had few direct tests. A litter decomposition study using grassland species, singly and in mixtures, was set up to see whether simple leaf traits could be used to predict the decomposition of leaf mixtures. Leaf Dry Matter Content (LDMC) was the trait that performed best. Mass loss in single species bags was best predicted using an exponential model. LDMC explained 48% of the variance in mixture mass loss. There was no significant impact of mixture species richness on mass loss. This study generally confirmed the predictions of the mass ratio hypothesis, but adds some support to other studies that indicate it needs broadening to take into account non-linear and threshold relationships between PFTs and ecosystem processes.

A field study was conducted to investigate the nutrient content of green and abscised leaves of Croton macrostachyus Del. and Millettia ferruginea (Hochst.) Baker and their decomposition to return these nutrients to the soil in the short-term. Green and abscised leaves were collected from trees of comparable size in Wondo Genet, Ethiopia, and were incorporated into litterbags to decompose for a period of 12 weeks. Green leaves of C. macrostachyus had significantly higher nutrient concentrations than those of M. ferruginea. In both species, green leaves had significantly higher (P<0.05) C, N and P and significantly lower (P<0.05) lignin and polyphenol concentrations than abscised leaves. Fifty percent of the biomass applied was lost during the first 7 weeks in C. macrostachyus, which was about 3 times faster than that of M. ferruginea. The half-lives of N and P were 5-8 weeks and 4-6 weeks, respectively, in C. macrostachyus; the corresponding values for M. ferruginea were 6-8 and about 22 weeks, respectively. Only 15.7% and 26.8% of green and abscised leaves of C. macrostachyus, respectively, were recovered after the 12 weeks of decomposition. The corresponding values were about 3.5-fold and 2.5-fold higher for M. ferruginea. Generally, leaves with higher initial lignin, polyphenol, lignin:N and C:N ratios had lower decomposition and mineralization rates. In both species, removal of leaf biomass before abscission (e.g. by pruning) could enhance both the quantity and rate of nutrient return to the soil.

The litterfall in a subtropical broadleaf forest within the Fushan Experimental Forest in northeastern Taiwan was monitored for 9 years. Mean annual litterfall was very sensitive to typhoon frequency and intensity, ranging from 3 to 11 Mg·ha -1 ·year -1 . Litterfall was significantly higher in years with strong typhoons than in years without typhoons, and the number of strong typhoons explained 82% of interannual variation in litterfall. Nutrient-use efficiency (dry mass/nutrients in litterfall) was high for N, but low for P compared with other tropical forests. This result supports the idea that the study forest is P limited but not N limited. Nutrient loss via litterfall represents a large percentage of aboveground biomass, especially during years with strong typhoons (e.g., 19%-41%, 15%-40%, 5%-12%, for N, P, and K, respectively). Forests that experience infrequent wind disturbance (e.g., temperate or boreal forests) can gradually regain any lost nutrients prior to the next disturbance; this is different from the situation observed in the Fushan Experimental Forest. At Fu-shan the pattern of not responding to typhoons with a flush of new growth appears to be an adaptation to the frequency with which there are multiple typhoons affecting the forest in a single year. Nutrient loss in litterfall caused by frequent typhoon disturbances appears to limit tree growth and contributes to the very low canopy height of the Fushan Experimental Forest.