Leaf Litter Accumulation Research Articles

Effects of different loads of Pinus pinaster Ait. litter and ash on the germination and growth of Cistus ladanifer L

Key messageCistus ladanifer L. shows an extraordinary plasticity of germination and growth. Fire promotes the regeneration of C. ladanifer by triggering its germination through thermal shock as well as by enhancing its seedling growth through the addition of ashes. On the contrary, stacking of Pinus pinaster Ait. leaf litter may hinder seedling establishment, at least in the first months after germination.ContextPinus pinaster Ait. is affected by forest fires in the Mediterranean basin. Its extreme flammability is due to the high spatial continuity together with the massive accumulation of leaf litter. Cistus ladanifer L. is a species which is widely distributed in the west Mediterranean region where it can form vast shrublands and flourish under these pinewoods. Although high temperatures associated with the occurrence of fire trigger germination of C. ladanifer, knowledge on how other factors, such as the presence of litter on the forest floor or the ash left after the fire, influence germination and seedling growth is essential to improve land management plans.AimsThe main objective of this study was to determine the effects of different loads of litter from P. pinaster and ash from their combustion on the germination and growth of seedlings of C. ladanifer.MethodsTwo experiments were carried out to assess the effect of heat shock (100 °C for 10 min) and two loads of litter and ash from P. pinaster (control, high and low loads of litter, high and low loads of ash) on the germination and growth after 2 and 4 months of C. ladanifer.ResultsHeat shock significantly increased the germination of C. ladanifer. In contrast, the addition of litter and ash had no effect on total germination but affected the growth of the seedlings coming from seeds exposed to heat shock. Litter treatments reduced biomass of 2 months seedlings and ash increased biomass of 4 months seedlings.ConclusionC. ladanifer is a species favoured by fire in different ways depending on the stage of regeneration. Germination is promoted by heat shock while seedling growth is favoured by ash nutrients. In contrast, pine leaf litter hinders seedling growth, although this effect disappears 4 months after germination. Alternative forest management practices to prescribed fires are recommended if preventing the spread of Cistus is a priority.

Fire effects on plant communities in Ozark woodlands and glades

BackgroundDecades of fire suppression caused drastic changes to community structure and composition across ecosystems, including in Ozark woodlands in Missouri, USA. Reintroducing fire can restore ground flora by reducing midstory tree density, increasing ground layer light, and reducing leaf litter accumulation, but we lack a clear understanding of how these effects vary across time and space. We investigated the effects of repeated prescribed fire on ground flora species richness, floristic quality, abundance, community composition, and stand structure over 20 years in a landscape matrix of dry-mesic woodlands, dry woodlands, and glades using data collected from the Ozark National Scenic Riverways Fire Effects Monitoring program in the Current River Watershed in the Missouri Ozarks.ResultsWe found that fire plays a key role in driving community structure and dynamics across community types, although with varying levels of intensity. Herbaceous species richness, abundance, and floristic quality index increased across all community types, while mean coefficient of conservatism decreased. Abundance and floristic quality effects were stronger in drier sites. Community composition changed with successive burns, resulting in several indicator species for post burn treatments. The density of midstory trees declined across community types with repeated fire. The number of burns significantly affected overstory tree density overall, but overstory tree density only declined in dry woodlands and glades and not in dry-mesic woodlands.ConclusionsOur results suggest that landscape fire shapes plant community structure and dynamics. Specifically, these findings show that fire effects vary among community types and suggest that land managers should consider landscape heterogeneity in fire application for restoration. Separate community types imbedded in the same landscape may respond to fire differently. Understanding repeated fire effects over several decades across multiple community types is critical to informing fire-driven woodland restoration across landscape scales.

Predicting the Occurrence of Forest Fire in the Central-South Region of China

Understanding the spatial and temporal patterns of forest fires, along with the key factors influencing their occurrence, and accurately forecasting these events are crucial for effective forest management. In the Central-South region of China, forest fires pose a significant threat to the ecological system, public safety, and economic stability. This study employs Geographic Information Systems (GISs) and the LightGBM (Light Gradient Boosting Machine) model to identify the determinants of forest fire incidents and develop a predictive model for the likelihood of forest fire occurrences, in addition to proposing a zoning strategy. The purpose of the study is to enhance our understanding of forest fire dynamics in the Central-South region of China and to provide actionable insights for mitigating the risks associated with such disasters. The findings reveal the following: (i) Spatially, fire incidents exhibit significant clustering and autocorrelation, highlighting areas with heightened likelihood. (ii) The Central-South Forest Fire Likelihood Prediction Model demonstrates high accuracy, reliability, and predictive capability, with performance metrics such as accuracy, precision, recall, and F1 scores exceeding 85% and AUC values above 89%, proving its effectiveness in forecasting the likelihood of forest fires and differentiating between fire scenarios. (iii) The likelihood of forest fires in the Central-South region of China varies across regions and seasons, with increased likelihood observed from March to May in specific provinces due to various factors, including weather conditions and leaf litter accumulation. Risks of localized fires are noted from June to August and from September to November in different areas, while certain regions continue to face heightened likelihood from December to February.

Habitat selection and refuge-use by a color polymorphic salamander reveal behavioral niche differences.

Color polymorphic species provide an excellent opportunity to investigate the ecology and evolution of intraspecific niche differences. The red-backed salamander, Plethodon cinereus, is a fully terrestrial lungless salamander with two common color forms, striped and unstriped. Previous research suggests the morphs may be differentially adapted to surface and subsurface microhabitats, with the unstriped morph being more fossorial. This hypothesis predicts that the unstriped morph should be more sensitive to the risks of surface activity (e.g., thermal stress, dehydration, predation), and therefore be more selective than striped morphs when choosing soil surface microhabitats. To test this hypothesis, we experimentally manipulated leaf litter mass in small forest patches (~0.45 m2). Leaf litter addition reduced soil temperatures, buffered against changes in air temperature, and likely provided physical protection from predators. Over 3 years, we found that unstriped adults responded positively to leaf litter addition, but striped adults did not. In addition, unstriped morphs spent significantly more time in protective refuges (opaque, moistened tubes) than striped morphs in laboratory assays. Taken together, the field and laboratory results support the hypothesis that the unstriped morph is more sensitive to the risks of surface activity, and therefore is more likely to be fossorial. This difference in microhabitat use, combined with spatiotemporal variation in leaf litter accumulation on the forest floor, may play an important role in the maintenance of the polymorphism.

Pengelolaan Daun Kering untuk Pupuk Kompos

A material given to plants to increase nutrient availability is called fertilizer. This research project aims to find a solution to the environmental pollution problem caused by the accumulation of dry leaf litter. Compost is made using dry leaf litter waste as the main component and EM4 as an aid. EM4 is responsible for breaking down the organic material in the leaves. The finished dry leaf compost is odorless, in the form of loose granules, has a brittle and somewhat rough texture, and is dark brown in color. The research method used is literature research, or research derived from books and print journals accessible on Google Scholar. This type of research uses descriptive studies and several works of researchers with relevant fields of study. Data collected through inductive methods are then analyzed using one or more initial data sets. The obtained data is examined using a descriptive analytical approach. By transforming dry leaves into more useful and economically valuable compost, this research also aims to develop and enhance the creative abilities of the community and the local economy. Bright colors indicate composting that is too dry or moisture levels below 30%. One determining factor of compost maturity is its aroma. The compost fermentation process will produce various strong aromas.

DUET - Distribution of Understory using Elliptical Transport: A mechanistic model of leaf litter and herbaceous spatial distribution based on tree canopy structure

Heterogeneity in surface fuels produced by overstory trees and understory vegetation is a major driver of fire behavior and ecosystem dynamics. Previous attempts at predicting tree leaf and needle litter accumulation over time have been constrained in scope to probabilistic models that consider a limited number of key factors influencing tree litter dispersal patterns and decomposition processes. We present a mechanistic model for estimating variation in surface fuels called the Distribution of Understory using Elliptical Transport (DUET). DUET uses a pre-generated voxelated canopy array and distributes the leaf litter from the trees in an elliptical shape based on tree species characteristics, wind data, and location-specific features. DUET then calculates grass growth between trees and around the litter patterns and sets moisture levels based on relative humidity. In this study, we use DUET to simulate spatial distributions of leaf litter and illustrate model sensitivity to several parameters, providing inputs for testing fuel spatial heterogeneity impacts on fire behavior using process-based models.

A spatially explicit model of tree leaf litter accumulation in fire maintained longleaf pine forests of the southeastern US

The continuity and depth of litter fuelbeds are major drivers of fire spread and fuel consumption. However, no established approach is available for the spatially explicit prediction of litter loads over large areas. Local fuel heterogeneity introduces large uncertainties on estimates derived from field-based models based on the extrapolation of sparse data samples. In fire-maintained pine forests of the southeastern US, litter accumulation and its distribution over the forest floor are mainly driven by vegetation productivity and by the number of years since the last fire (YSF). Some ecological models that simulate fire effects allow for a time-dependent estimation of litter by accounting for the opposing rates of litter deposition and decomposition as a function of YSF at the landscape level, but they do not account for spatial heterogeneity. We developed a conceptually simple approach for wall-to-wall estimation of tree leaf litter loads at high spatial resolution (5 m). The approach involved, first, estimating spatial patterns of tree annual litterfall. We mapped individual tree crowns through segmentation of airborne laser scanning (ALS) data, and we estimated crown foliage biomass using tree inventory data and ALS derived tree crown attributes. Tree annual litterfall was calculated as a fraction of the crown foliage biomass based on leaf turnover rates. We then quantified tree leaf litter accumulation through a spatially explicit implementation of the established Olson (1963) accumulation and negative decay model. We tested and validated our model in several management and research units at Eglin Air Force Base (Florida), Pebble Hill Plantation (Georgia), and Osceola National Forest (Florida), where managers maintain predominantly longleaf pine forests using frequent fire. Pixel-level RMSD and BIAS between tree leaf litter biomass estimated by the proposed model and reference field measurements were 0.21 and 0.01 kg m−2, and area-level RMSD and BIAS were 0.09 and 0.01 kg m−2. We concluded that linking patterns of litterfall and tree leaf litter accumulation to tree crown objects provides a means to characterizing the discontinuity of the litter layer, accounting for spatial heterogeneity largely traceable to tree crown foliage inputs.

Pinus contorta Alters Microenvironmental Conditions and Reduces Plant Diversity in Patagonian Ecosystems

Pinus contorta is considered one of the most invasive tree species worldwide, generating significant impacts on biodiversity and ecosystems. In several Patagonian ecosystems in southern Chile, it has escaped from plantations established mainly in the 1970s, and is now invading both forests and treeless environments. In this study, we evaluated the impact of the invasion of P. contorta on microenvironmental conditions in Araucaria araucana forest and Patagonian steppe ecosystems, and assessed how these changes related to the richness and abundance of native and non-native plant species. In each ecosystem, 24 plots of 100 m2 were established along a gradient of P. contorta biomass, where 18 environmental variables and the composition of native and non-native vegetation were measured at a local scale. Our results indicated that increased pine biomass was associated with differences in microclimatic conditions (soil and air temperature, photosynthetically active radiation (PAR), and soil moisture) and soil properties (potassium, nitrate, pH, and litter accumulation). These changes were ecosystem dependent, however, as well as associated with the level of invasion. Finally, the reduction in the richness and abundance of native plants was associated with the changes in soil properties (accumulation of leaf litter, pH, and organic matter) as well as in the microclimate (minimum air temperature, PAR) generated by the invasion of P. contorta. Overall, our results confirm that the invasion of P. contorta impacts microenvironmental conditions (i.e., canopy cover, litter accumulation, minimum air temperature, and maximum soil temperature) and reduces native plant diversity. For future restoration plans, more emphasis should be given to how environmental changes can influence the recovery of invaded ecosystems even after the removal of the living pine biomass (i.e., legacy of the invasion).

ECOLOGICAL REHABILITATION INDICATORS FOR ONE EUCALYPTUS REFORESTATION WITH AN OAK FOREST AS REFERENCE

The evaluation of reforestation for ecological restoration purposes in an area requires the comparison of similarity indicators with nearby reference forests. The objective of this study was to compare the vegetal composition, structure, falling debris, and their decomposition in the soil of a reforestation site of Eucalyptus camaldulensis Dehnh, planted more than 50 years ago, and a neighbouring forest dominated by Quercus deserticola Trel. and Q. laeta Liebm (used as reference), in an area of the State of Mexico; and obtain quantitative indicators of the trajectory of rehabilitation through the use of non-native species of Mexico. In reforestation and oak forest, we established 12 sampling sites where the composition, structure and two ecological processes (falling debris and decomposition) were determined. In addition, solar radiation was estimated by taking zenith photos of the canopy, using a hemispherical lens. When data was within normal distribution, we used the Student test, and when it was not, the Wilcoxon test was used to compare the variables studied. The reference forest outperformed reforestation (p ≤ 0.05) in: richness (68 and 50 species); diversity (Simpson index, 1.6-2.6 and 0.7-2.3); normal diameter (21.3 and 13.7 cm), accumulated leaf litter (18.2 and 9.2 Mg ha-1), detritus fall (0.606 and 0.321 Mg ha-1 per month), and litter decomposition (0.443 and 0.251 Mg ha-1 per month). Reforestation had a higher total radiation (5384 vs. 4376 MJ m-2 year-1) and tree height (8.1 vs. 7.4 m). The percentage values of importance were 32.8 and 26.9 % for Quercus deserticola and Q. laeta in the oak forest, and 70 % for E. camaldulensis in the reforestation. After 50 years, reforestation still showed statistical differences from forest in composition, structure, and soil processes.

The forest effect: Biosphere 87Sr/86Sr shifts due to changing land use and the implications for migration studies

This study documents a transect of 87Sr/86Sr values from a variety of plant, soil and rock samples across the ancient woodland of the Sherwood Forest National Nature Reserve (SFNNR) and into adjoining farmland in Britain. All samples were collected from the Triassic Sherwood Sandstone Group. A shift of +0.0037 in 87Sr/86Sr values is observed between the average plant from the biosphere of the ancient forest and that of the farmland. This shift is caused by the leaf litter accumulation in the forest, through time, leading to soil acidity that leaches out the carbonate component of the soil. This results in the forest floor soil reflecting only the silicate minerals from the original Sandstone rock formation. We have named this process “the forest effect”. Rock samples from boreholes of the Sherwood Sandstone Group, as well as water samples from aquifers and mineral waters from previous studies, further indicate that the change in biosphere 87Sr/86Sr is a result of the wooded environment rather than the anthropological addition of lime to farmland.The extent of the forest effect will vary with differing lithologies with the most susceptible terrains being those with mixed carbonate-silicate composition, and it may be sufficient to impact the interpretation of animal and human 87Sr/86Sr in studies of mobility and migration. The model provides an opportunity to understand and assess food procurement strategies and animal management practices in the past, as well as the interaction of humans with their natural environment.

The Effect of Accumulation of Leaf Litters and Allelochemicals in the Soil to the Sustainability of the Newly Introduced Crop Plants

Indonesia is the second-largest vanilla production and the third-largest cocoa production in the world, but it sustained for a short period. The unsustainability of these crops is speculated to occur because of the change in leaf litter accumulation which affected the sustainability of soil organic carbon that plays an important role in maintaining soil health and fertility. To find out methods that could improve the sustainability of the production, a literature review was conducted. The articles, related to the sustainability of vanilla and cacao production, were collected using Google Scholar, Wiley Online Library, ResearchGate, and Google Chrome browser. Keywords were employed to find the articles includingsoil organic carbon, cocoa plantation, vanilla, leaf litter, and allelochemical. This current article review foundthat introducing crop by clearing of previously existing vegetation could severely reduce the rate of leaf litter accumulation. Consequently, in a prolonged period, the soil organic carbon and soil fertility are very low and are unable to support the healthy growth and production of the crops. To restore production, the plantation then is returned to more traditional agroforestry such as replanting shading trees and addition of mulch. However, in the higher density of canopy, the crop production is low attributed partly to the decreasing soil pH which increases the impact of allelochemical. This review concluded that the sustainability of leaf litter accumulation is crucial to maintain soil health, but mitigation is required to reduce the impact of allelochemical accumulation.

Habitat heterogeneity increases leaf litter retention and fragmentation in a Cerrado savanna stream

Leaf litter fragmentation is one of the main determinants of the availability of food resources for aquatic biota, and this process is strongly influenced by the retention capacity of streams. Retention capacity depends on habitat heterogeneity, as well as on other factors such as leaf litter characteristics and microhabitat diversity. However, the effects of these factors have not yet been clearly understood. In this study, our hypotheses were as follows: (i) habitat heterogeneity increases leaf litter retention, particularly of larger leaves, and (ii) water flow enhances leaf litter fragmentation by promoting physical abrasion of leaf litter, particularly of softer leaves. We tested these hypotheses using (i) the proportion of leaves in transport and the variation of retentive structures such as rock, pebbles, trunks, and roots for habitat heterogeneity in three reaches and (ii) litterbags of two mesh sizes (fine and coarse) incubated in riffle and pool habitats in three reaches of a headwater stream of the Cerrado biome. Our results demonstrated that habitat heterogeneity and leaf litter size increased leaf litter retention rates, and that water flow is an important factor for leaf litter fragmentation in tropical streams. Large leaves interacted with local conditions of streambed heterogeneity (trunks and roots) to reduce transport distances, and hydrology (water flow) accelerated the fragmentation of soft leaves. Our findings suggest that management strategies promoting the accumulation of woody leaf litter ​in the streambed (trunks and roots) can be valuable to increase the retention capacity of streams, on the other hand the water flow increases the processing of allochthonous organic matter.

Urbanization affects oak–pathogen interactions across spatial scales

The world is rapidly urbanizing, thereby transforming natural landscapes and changing the abundance and distribution of organisms. However, insights into the effects of urbanization on species interactions, and plant–pathogen interactions in particular, are lacking. We investigated the effects of urbanization on powdery mildew infection on Quercus robur at continental and within‐city scales. At the continental scale, we compared infection levels between urban and rural areas of different‐sized cities in Europe, and investigated whether plant traits, climatic variables and CO2 emissions mediated the effect of urbanization on infection levels. Within one large city (Stockholm, Sweden), we further explored whether local habitat features and spatial connectivity influenced infection levels during multiple years. At the continental scale, infection severity was consistently higher on trees in urban than rural areas, with some indication that temperature mediated this effect. Within Stockholm city, temperature had no effect, while local accumulation of leaf litter negatively affected powdery mildew incidence in one out of three years, and more connected trees had lower infection levels. This study is the first to describe the effects of urbanization on plant–pathogen interactions both within and among cities, and to uncover the potential mechanisms behind the observed patterns at each scale.

Habitat characteristics and climatic factors influence microhabitat selection and arthropod community structure in a globally rare central Appalachian shale barren.

The central Appalachian shale barrens, a globally unique habitat type restricted to the eastern United States, presents an insular and physiologically stressful environment with sparse vegetation and extreme ground surface and air temperatures. Despite the high levels of plant species endemism within these systems, information on invertebrate communities and habitat preferences is extremely limited.Through this study, we aimed to better understand a shale barren arthropod community, microhabitat selection, and the influence of habitat characteristics and climatic factors. We employed pitfall traps to sample epigeic arthropods during the 2016 growing season in a shale barren habitat.Arthropod community composition was driven by overstory trees, mediated through accumulated leaf litter and availability of shaded microhabitats. Ambient air temperature also influenced the surface activity of various taxa with spiders decreasing at higher temperatures and ants, crickets, flies, and harvestmen all increasing in relative abundance.Habitat integrity of the central Appalachian shale barrens is threatened by forest succession and mesophication, encroaching invasive plant species, and rising ambient air temperatures, all of which can alter the extent of overstory vegetation and availability of shaded microhabitats. These biotic and physical pressures will subsequently affect epigeic arthropod community composition, depending on adaptive capacity of individual taxa.To the authors’ knowledge, these findings constitute only the second published work on arthropod communities and the first to focus on epigeic taxa in this globally rare habitat type. Continued conservation of these unique, insular habitats and their adapted inhabitants requires a multifaceted approach that considers current and future conditions.

Flow intermittence alters carbon processing in rivers through chemical diversification of leaf litter

AbstractThe dry phase of intermittent rivers promotes the accumulation of leaf litter on various terrestrial and aquatic habitats. This environmental heterogeneity causes a chemical diversification of leaf litter by a range of physical and biological degradation processes acting across the various habitats. After flow resumption, the chemically diversified leaves are mixed and subject to continued decomposition downstream. We hypothesized that the chemical diversification of leaf litter during the dry phase would affect leaf litter decomposition under re‐established lotic conditions. Our laboratory treatments mimicking dry‐phase habitats caused a strong chemical diversification of leaf litter, which—upon combination in mixed litter bags—accelerated its decomposition in a perennial river reach. We suggest that intermittent rivers may act as hotspots of organic matter diversification, with potential implications for organic matter processing at the river‐network scale.

Investigation of biological activity of recultivated iron ore processing wastes of Abagur agglomeration and processing plant, Novokuznetsk

The problem of biotransformation of man-caused disturbed lands is of great importance for the restoration of soil fertility. The leading role in this process is played by soil microorganisms. Toxic industrial waste can make negative adjustments to the species composition of soil microflora (can cause mutation of many microorganisms, as well as the death of some of them). Under certain conditions, in the presence of harmful substances, new microorganisms can arise that decompose precisely those substances that cause soil pollution. Consequently, a new microflora appears, capable of carrying out its trophic functions on an inductive basis on industrially contaminated substrates. As a man-caused control, a mineral substrate of the tailing dump of Abagurskaya agglomeration and processing plant JSC, unfavorable for the vital activity of soil microflora, where, due to the absence of plant residues and other carbon-containing components, an extremely low level of intensity of enzymatic hydrolytic processes was used. The introduction of organic matter containing sewage sludge (WWS) into the substrate as a recultivator creates favorable conditions for the formation of a stable vegetation cover. The presence of an organic component in the mineral substrate of the iron-containing tailings waste creates favorable conditions for the vital activity of microflora. Carbon-containing compounds of technozems create a certain pool of microorganisms. The products of their vital activity create the basis for the formation of an organic-mineral substrate, favorable conditions for the growth of higher plants and the creation of a stable phytocenosis. For the induced manifestation of enzymatic activity under these extreme conditions, a considerable time is required for the bacterial forms introduced from the outside to be able to fix their presence. The maximum activity, comparable both after 1 month and after 3 months with the natural control, was noted on the experimental site with the placement of WWS as a soil conditioner. The presence of WWS and intensive accumulation of leaf litter and other plant residues contribute to the favorable development of cellulose-degrading bacteria, among which rod-shaped forms of the genus Clostridium predominate. The quantitative indicators of the enzymatic activity of technozems are close to the natural level and significantly exceed those of technogenic control.

Some like it hot: Drought-induced forest die-off influences reptile assemblages

Vegetation changes as a direct result of climatic shifts changes are likely to influence reptile communities reliant on forest habitat structure and health. Extreme heat and drought over the summer of 2010/11 caused canopy collapse and decline in a Mediterranean-type forest, southwest Western Australia. The loss of canopy and altered abiotic and biotic conditions changed habitat availability for fauna. A survey of reptile assemblages and vegetation was carried out over the summer of 2013/14, three years after the drought event. Reptiles were captured using camera traps and pitfall traps. Surveys were carried out at four independent locations, where trap stations were set up across drought-affected and adjacent healthy (not visibly affected) sites (total 32 trap stations). Habitat variables likely to influence reptile assemblages (leaf litter, coarse woody debris) were measured, and iButtons were used to capture temperatures within microhabitats likely to be used by reptiles. Reptile assemblages observed at drought-affected sites differed to assemblages observed at healthy sites. These differences could be related to warmer and colder temperature extremes in drought-affected sites compared with healthy sites. Coarse woody debris was readily available in drought-affected sites but leaf litter accumulation was significantly less in drought-affected sites compared to healthy sites. Drought events are becoming more commonplace and it is important to understand the repercussions of forest decline on reptile assemblages. More proactive approaches for maintaining native habitat, such as shelter structures, may be required to protect species in affected sites to ensure that ecosystem processes are not lost.

Influence of Environmental Variables on the Natural Regeneration of a Forest under Restoration after Bauxite Mining and in a Reference Ecosystem in Southeastern Brazil

The shrub-tree floristic composition of the natural regeneration stratum of a bauxite mine in the process of restoration and in a reference ecosystem (remnant of a preserved secondary Seasonal Semi-Deciduous Forest) were analysed to evaluate forest restoration conditions after five years of planting. The influence of canopy openness, accumulated leaf litter and soil attributes in the regeneration stratum were also investigated in both the forests. The floristic composition of the regeneration stratum in the forest under restoration (16 species and 5,083 individuals ha-1) and in the reference ecosystem (58 species and 26,250 individuals ha-1) are distinct due to the difference in the environmental variables. Results showed that the reference ecosystem favours the presence of species that tolerate environments with greater shading and higher aluminium and organic matter content in the soil like Psychotria carthagenensis Jacq., while the forest under restoration favours the presence of species adapted to fertile soils and those that tolerate greater luminosity like Vernonanthura phosphorica (Vell.) H.Rob.

Effects of Phylloicus case removal on consumption of leaf litter from two Neotropical biomes (Amazon rainforest and Cerrado savanna)

Phylloicus (Trichoptera, Calamoceratidae) is a stream invertebrate widely distributed across Neotropical biomes, which larvae use allochthonous leaf litter as food resource and to build a case that offers protection against predation. Seasonal changes in leaf litter accumulation on the streambed may affect Phylloicus larvae due to variations in availability of food and case-building material; however, it is unclear how these two processes influence each other. We assessed how case removal affected leaf litter consumption by Phylloicus larvae from two Neotropical biomes (Amazon rainforest and Cerrado savanna), which were experimentally offered leaf litter of Goupia glabra and Maprounea guianensis (common riparian species from the rainforest and savanna biomes, respectively). Our treatments included (i) direct effect of case removal, where larvae had their case removed during the experiment; (ii) time-lag effect, where the case was removed and larvae were allowed to rebuild the case before starting the experiment; and (iii) control, where cases were not removed. Leaf litter consumption by Phylloicus was 9.16 ± 7.47 mg/mg on average, being higher in the savanna than in the rainforest experiment (possibly in relation to a higher difference between the rainforest stream temperature and the experimental temperature, which may have inhibited larval activity), and higher on M. guianensis than on G. glabra (most likely due to the higher leaf litter quality of the former species). Consumption was higher in the time-lag effect treatment than in the direct effect and control treatments, which could be explained by an increase in the larval energetic demand for case building.

Composition of the soil fauna community and leaf litter stock in agro-forestry systems and secondary forestry

Agro-Forestry Systems (AFS), in addition to being a means of providing income, can be considered an alternative way of helping conserve biodiversity, both above and below ground. The aim of this study was to evaluate the accumulation of tree leaf litter and its nutrient content as well as the composition of fauna in the soil-litter layer in two Agro-Forestry Systems (AFS-1 and AFS-2), using as reference an area of secondary Forest (SF), in the Quilombola do Campinho da Independência community, Paraty, in the state of Rio de Janeiro (RJ), Brazil. The collection of accumulated leaf litter and soil-litter fauna was carried out from four sample points in each area and at two different seasons of the year, the rainy and the dry season. The leaf litter stock and its nutrient content (Ca, Mg, P, K and N) were measured. The extraction of fauna was carried out according to Tüllgren’s method, modifying the Berlese funnel. The stock of accumulated leaf litter differed between the two areas only in the rainy season; the amounts were smaller in AFS-2. In general, the Agro-Forestry Systems were very similar to the secondary forest in terms of levels and/or stock of nutrients in the majority of cases, at least in one of the seasons studied. The composition of the soil fauna groups in the Agro-Forestry System (AFS-1 and AFS-2) had a high degree of similarity to that found in the forest, and these systems mainly favour the populations of groups like Collembola and Formicidae.