Litter Layer Research Articles

Influence of forest vegetation restoration on carbon increment after mining

We have clarified the study area has a history of 65 years and has been restored for 6 years. This study investigated the carbon storage characteristics of undisturbed natural forests and restored mining vegetation in Yunnan Province, China. The goal was to quantify carbon reserves and increments to inform ecological restoration strategies. Four vegetation components (tree, shrub, herb, litter) and five soil layers (0–10, 10–20, 20–30, 30–40, 40–60 cm) were analyzed. In natural forest, the tree layer stored 60% of carbon (273 Mg ha−1), overwhelmingly dominating vegetation carbon stocks. Shrub, herb, and litter layers each comprised < 1%. Surface soil layers (0–30 cm) stored 64% of soil carbon. In the restored mining area, the tree layer contributed 75% of vegetation carbon increment (16 Mg ha−1), though stocks were lower than natural forest. Soil layers showed the highest carbon increment (69%) despite lower biomass than natural conditions. Unexploited forests thus exhibit robust carbon storage, while restored mining areas have weaker carbon gains, indicating recovery potential. Strategic interventions targeting soil quality, stimulating vegetation growth, and increasing carbon sequestration could significantly augment reserves and ecological functionality. Prioritizing vegetation succession and soil revitalization are paramount to ensuring ecological integrity and sustainable development. Fostering a positive regional ecological feedback loop will be pivotal. This research quantifies carbon storage differences between undisturbed and restored mining areas, highlighting soil and vegetation as critical targets for optimizing carbon sequestration and ecosystem recovery in degraded environments.

La descomposición de la hojarasca de Ochroma pyramidale (Malvaceae)

The tree Ochroma pyramidale is used to recover jungle areas that have been cultivated. This native species generates a thick layer of leaf litter that remains for several years. The objectives of this study were: 1) to know how much leaf litter is produced, 2) to estimate how long it persists in the soil, and 3) to identify the role of soil fauna in its decomposition. Leaf litter production was estimated at 11 Mg/ha/year, while over the course of 13 years the biomass and depth of the leaf litter layer measured in three sites previously planted with Ochroma showed a decrease of over 60%. In a leaf litter decomposition experiment, 37% of biomass was lost in 180 days. Soil mesofauna reduced the concentration of cellulose in leaf litter, while lignin decreased due to the time of permanence of the leaf litter in the soil. The high C:N proportion of the leaves, together with high lignin concentrations, could explain the low levels of loss and accumulation of biomass.

Farmer Options and Risks in Complex Ecological-Social systems: The FORCES game designed for agroforestry management of upper watersheds

CONTEXTSerious games have gained popularity as an innovative participatory approach to explore the complexity of social-ecological systems, managing the trade-offs between economic and ecological targets. Serious games can be abstract and generic, or more complex and specific. They can be used to raise awareness, increase shared understanding of options and risks, and/or commitment to common goals. OBJECTIVEWe here aim to clarify design principles applied in the FORCES game (Farmer Options and its Risk in Complex Ecological-Social systems) as single-player game to be easily adaptable to diverse (upper) watershed contexts. Three steps involved are game design (balance generic and site-specific information), game use in (and possibly adaptation to) specified context(s) and evaluation of contextualized impacts. METHODSThe FORCES game design was based on three contrasting watershed case studies in East Java, Indonesia, rather than on single, specific case study. Game development consisted of preparation (defining the context, generic core issues and game objectives), development process (ideating, setting the actors, resources, elements, and mechanisms), and assessment (prototyping, exploration of solution space, game trial and player feedback). Fifty-five smallholders played the FORCES in three landscapes to test the game's performance and impact on participants' insights. Therefore, we recorded every game session and performed pre- and post-game interviews for each participant. RESULTS AND CONCLUSIONSThe developed FORCES game focuses on decisions of individual farmers involving plot-level plant (annual crops, trees) choices with financial cost-benefits consequences and links to ecological impacts on the litter layer, water balance, and erosion. The FORCES game was successfully applied in three distinct landscapes, demonstrating its adaptability. The game's generic water balance supported the transferability to different contexts, while fine-tuning of plot management options to reflect local variation was simple due to the solid underlying game mechanics. According to players, the game reflects local dynamics in the landscapes and provides a realistic experience, triggering participants to make decisions close to their real-life choices and learn from the consequences. While the game has limited representation of social interactions due to its single-player design, FORCES allowed relational values to be recognized in players' responses. SIGNIFICANCEBalancing the combination of generic setting with easily adaptable site-specific elements in the game design plays an essential role to increase game adaptability and reusability to different locations. FORCES adds to the growing array of games that can be used to support farmers' participation in higher-level decision-making processes to secure environmental services in productive landscapes.

Initial effects of crop tree release and traditional thinning on productivity and carbon storage of Cunninghamia lanceolata plantation

IntroductionThinning has a crucial impact on the carbon dynamics of forest ecosystems. The inconsistencies about the effects of thinning on carbon stocks in previous studies may be attributed to different thinning plans that designed to achieve different management goals.MethodsThis study focuses on Cunninghamia lanceolata as the research object and investigates three treatments: crop tree release (CTR), traditional thinning (TM), and no thinning (CK). The different thinning methods (CTR and TM) had different management objectives and selection of crop trees principle, although with the same thinning density. The short-term effects of CTR and TM treatments on tree growth and carbon storage in Cunninghamia lanceolata plantations were analyzed and compared.ResultsBoth CTR and TM were beneficial to the growth of individual trees when compared to CK, with CTR being more beneficial. The average annual increments in DBH, TH, and volume of a single tree in CTR increased by 62.50%, 61.29%, and 74.07% higher than CK, respectively. So CTR was the best for large-diameter timber yield, which was 77.40% higher than CK, whereas CK had a higher proportion of medium- and small-diameter timber yield. However, CTR had an insignificant short-term boosting effect on stand volume, and its timber volume was considerably higher than that in TM treatment, but not as high as in CK. Therefore, the carbon storage in the tree layer, litter, and different soil layers under different treatments showed that CTR and TM were significantly lower than CK. And the total carbon storage in the three treatments showed that CK &amp;gt; CTR &amp;gt; TM, with CTR showing a 13.07% higher than TM. On the contrary, thinning could effectively improve understory vegetation carbon storage. The carbon storage in the herb and shrub layers under CTR increased by 47.77% and 183.44%, respectively, compared to CK.DiscussionAlthough thinning could significantly promote the growth of individual trees and understory vegetation, their total carbon storage in the short term was lower than that in CK. CTR showed a higher carbon sequestration and sink capacity than TM. It suggests that CTR, as a special type of thinning method, should be encouraged to selected because it has the chance to achieve a faster carbon sequestration rate than traditional thinning and it also can produce higher-quality timber.

Pedogenic controls of soil organic carbon stocks and stability beneath montane Norway spruce forests along a precipitation gradient

Reliable data on SOC stocks in forest soils is required in the context of climate change and soil health assessments but still limited by input data availability (e.g., bulk density) and methods used for stock calculation. Relatively few studies have investigated the stability of SOC in forest soils. We investigated SOC stocks and fractionation in soils beneath Norway spruce forests and grasslands in the montane zone along a gradient of mean annual precipitation (MAP). We sampled soil cores volumetrically to 40 cm depth and measured SOC in the fractions <2 mm (fine earth), >200 μm and 200–20 μm (coarse and fine POM), and <20 μm (MAOM) along with potential pedogenic controls. Total SOC stocks beneath forests in the study region, calculated by the equivalent soil mass (ESM) approach to 40 cm depth, amount to 79.0 ± 29.9 (mean ± standard deviation) Mg ha−1 (n = 20) in the mineral soil, and to 92.9 ± 30.6 Mg ha−1 including the litter layer, with a share of 55 % associated with POM. MAOM makes up ∼41 % of SOC in the uppermost mineral layer (0–5 cm) and increases to 71 % in the subsoil (20–40 cm). Multiple regression models show that MAOM is largely controlled by ammonium oxalate extractable Al (Alo) in the forest subsoils (20–40 cm), and increases with MAP in the topsoil layers (0–20 cm). Soils on carbonate rock stand out with ∼80–100 % larger shares of MAOM in the uppermost soil layers (0–10 cm) which is likely connected to higher soil pH and MAP, supporting microbial transformation and subsequent stabilisation of organic matter, which is reflected in narrower C:N ratios in MAOM and SOC.Including the litter layers, ESM-based total SOC stocks in forest soils tend to exceed those beneath grassland (80.2 ± 21.9 Mg ha−1; n = 31) by 16 %, but only by 6.4 % if calculated by the conventional fixed-depth (FD) approach. In contrast to the forest soils, SOC stocks beneath grasslands are dominated by MAOM (75.6 %).We conclude that (coniferous) forest soils are a poor reference for establishing sequestration potentials for stable SOC. The observed large proportion of POM in forest topsoils and its increase with declining MAP (indicating water availability) suggests a risk of SOC losses in response to increasing droughts due to climate change.

Spider fauna (Arachnida, Araneae) in Mordovia State Nature Reserve and National Park "Smolny" (Russia).

Ecosystems in protected areas are richer in animal and plant species diversity ("biodiversity hotspots") due to more stringent conservation conditions. Of particular importance is scientific research and monitoring of this diversity in such areas. The aim of this study is to describe a set of data on Araneae occurrence in two protected areas: Mordovia State Nature Reserve and National Park "Smolny". About 29,000 individuals are identified to the species level. In total, 342 species were recorded for both PAs. The greatest species diversity was recorded in the families Linyphiidae (109 species; 32%), Lycosidae (38 species; 11%) Gnaphosidae (28 species; 8%), Araneidae (25 species; 7%), Salticidae (24 species; 7%), Thomisidae (23 species; 7%) and Theridiidae (22 species; 6% from total species diversity). The five species most abundant in the lower stratum (litter and moss layer) of biocenoses were Diplocephaluspicinus, Micronetaviaria, Tenuiphantestenebricola, Diplostylaconcolor and Abacoproecessaltuum and the five species most abundant in the vegetative stratum (herb, shrub and tree stems and canopy) were Linyphiatriangularis, Enoplognathaovata, Evarchafalcata, Misumenavatia and Evarchaarcuata. The dataset contains information on the occurrence of seven rare species (Centromerusnurgush, Centromeruspersimilis, Diplocephalusdentatus, Entelecaraflavipes, Metapanamomopskaestneri, Pelecopsisradicicola and Porrhommamicrocavense), three species (Agalenatearedii, Neosconaadianta, Thanatusoblongiusculus) that entered here from the steppe zone and two synanthropic species (Steatodacastanea, Tegenariadomestica).

Identifying the abiotic factors that determine the inland range limits of a mesic-adapted lizard species.

For most species, the factors that determine geographical range limits are unknown. In mesic-adapted species, populations occurring near the edge of the species' distribution provide ideal study systems to investigate what limits distributional ranges. We aimed to identify the abiotic constraints that preclude an east-Australian mesic-adapted lizard (Lampropholis delicata) from occupying arid environments. We performed lizard surveys at sites spanning an elevation/aridity gradient (380-1070 m) and measured the prevalence of habitat features (logs, rocks, leaf litter, bare ground, solar radiation) in addition to hourly temperatures in a variety of microhabitats available to lizards. Species distribution models (SDM) were used to identify the macroclimatic variables limiting the species' distribution. At its inland range limit, L. delicata is associated with mesic high-elevation forests with complex microhabitat structures, which gradually decline in availability toward lower (and more arid) elevations where the species is absent. Moreover, L. delicata is absent from sites with a shallow leaf litter layer, in which daily temperatures exceed the species' thermal preference range, which we determined in a laboratory thermal gradient. In regards to macroclimate, SDM revealed that temperature seasonality is the primary variable predicting the species' distribution, suggesting that L. delicata avoids inland areas owing to their high annual thermal variability. By combining multiple lines of evidence, this research highlights that habitat and microclimate suitability-not solely macroclimate suitability-are important range-limiting factors for mesic ectotherms and should be incorporated in studies addressing range-limiting hypotheses.

Carbon Stocks and Transfers in Coniferous Boreal Forests Along a Latitudinal Gradient

Carbon (C) sequestrated in the boreal forest ecosystems plays an important role in climate regulation. This study’s objectives were to quantify the differences in the components of the forest C cycle along a 1000 km latitudinal gradient within the boreal region and between dominant coniferous species in Fennoscandia. The study included seven xeric–sub-xeric and eight mesic–herb-rich heath forests dominated by Scots pine and Norway spruce, respectively. The total site carbon stock (CS) ranged from 81 to 260 Mg ha−1. The largest ecosystem component CSs were tree stems, mineral soil, and humus layer, representing 30 ± 2%, 28 ± 2%, and 13 ± 1% of total CS, respectively. On average, the spruce sites had 40% more C than the pine sites, and CS stored in most compartments was higher on spruce than on pine sites. As exceptions, understorey vegetation and litter layer had a larger CS on pine than on spruce sites. The northern sites had an average of 58% less C than the southern sites. Humus layer CS was the only compartment showing no latitudinal trends. Northern sites had a significantly larger fine and small root CS and understorey CS than southern sites. Most CS compartments were significantly correlated with litterfall C transfer components. Dissolved organic carbon (DOC) flux in throughfall was positively correlated with the aboveground tree compartment CS. Our study revealed patterns of C distribution in major boreal forest ecosystems along latitudinal and fertility gradients, which may serve as a reference for Earth system models and in the evaluation of their projections.

Diversity, Abundance and Distribution of Gastropoda in a Tropical Agricultural Village in Kadavoor, Kerala, India

Gastropods are an ecologically significant taxon which take part in crucial ecosystem services like nutrient cycling, food web, calcium cycle, pollination and seed dispersal. The gastropod diversity of Kadavoor village was studied for eight months in monoculture plantations of pineapple, rubber, banana, mixed crop agroecosystems, paddy fields and freshwater bodies. Random sampling was employed monthly in five quadrats of 1 * 1 square metre. A total of 14 species belonging to two subclasses, four orders and nine families were recorded. These include land snails, freshwater snails, slugs and semislugs. Six out of 14 species recorded are endemic to the Indian subcontinent. Two invasive species namely Laevicaulis alte and Allopeas gracile were recorded. It is notable that Achatina fulica was not recorded during our study. Ariophantidae was the most abundant family followed by Subulinidae. The mixed crop agroecosystem was found to be more species-rich than monoculture plantations which might be due to an increase in microhabitats and leaf litter layer. The Simpson’s diversity index values are highest for the rubber plantation and lowest for the banana plantation since the species are more evenly distributed in the rubber plantation. Mariaella dussumieri is a constant species in all three monoculture plantations since its constancy value is greater than 50%. Sorenson’s similarity index for species composition between monoculture ecosystems is high but variable. Microhabitats of snails in all these ecosystems were also recorded. The study is a first attempt at the gastropod diversity of agroecosystems in Kerala and would help in the conservation and management of the gastropods.

Soil erosion under forest hampers beech growth: Impacts of understory vegetation degradation by sika deer

The overpopulation of large herbivorous mammals degrades understory vegetation and hence promotes soil erosion in some northern hemisphere forests. Topsoil removal via erosion reduces soil water and nitrogen (N) content as well as exposes tree roots. However, whether topsoil removal inhibits tree growth through water and N uptake limitations has not been examined. This study aimed to measure the vertical length from exposed roots surface to the soil surface (exposed root height; ERH) under degraded forest understory vegetation and to evaluate its influence on tree growth. Specifically, we examined the relationships between ERH and beech growth and identified the timing of growth reduction based on annual tree-ring analysis at the individual scale. Furthermore, we discussed the effects of water and N limitations on beech growth reduction. We studied 12 Japanese beech trees on Mt. Sanpo, southern Kyushu Island, Japan, where understory vegetation was degraded and lost due to herbivory by Japanese sika deer from 1980 to 2003. Lower amounts of leaf production and relative growth rates of stem basal area increment (BAI) were observed in beech trees with higher ERH. Segmented regression analysis, which detects the changing time of a temporal trend (i.e., break-point), revealed that the BAI has resulted in a decreasing trend after 1997.6 ± 9.0 (yr), which coincided with the field observations on understory degradation in the study site. After the break-point of the BAI, the BAI of each study tree was negatively related to intrinsic water use efficiency, an integrated index of water limitation. These results suggest that soil erosion after the degradation of understory vegetation reduced beech growth, possibly because of the water limitations associated with root exposure. Reduced beech growth will reduce the supply of the litter layer that prevents topsoil erosion, which may enhance further soil erosion and tree growth reduction.

Multi-Scale Altitudinal Patterns of Soil and Litter Invertebrate Communities in a Warm Temperate Deciduous Broadleaf Forest

The diversity and spatial patterns of soil invertebrates are the cornerstones for understanding their ecological functions, which are crucial to maintaining nutrient cycling and soil health in forest ecosystems. Based on a continuous altitudinal gradient (1020–1770 m) composed of 119 plots, this study analyzed the spatial patterns of invertebrate communities in temperate mountain forest litter and soil using multi-scale ordination. The results indicate that along the altitudinal gradient, the invertebrate communities in both litter and soil layers exhibit “patches” at a scale of approximately 33 plots that are mainly composed of Mesostigmata and Apterogasterine oribatid mites. In the litter layer, at the 11-plot scale, an aggregation of Onychiuridae is also formed, while in the soil layer, there are “patches” represented by Diadocidiidae at the 33-plot scale. The positive–negative associations among invertebrate taxa also shift between the litter and soil layers, as well as among “patches”. Our study confirms that the richness of invertebrates in temperate-forest litter is higher and forms multi-scale assembly “patches” despite the higher abundance of invertebrates in the soil layer. Future studies should delve deeper into the aggregation mechanisms of these specific taxa and may require higher sampling densities to reveal the multi-scale spatial patterns of soil invertebrates.

The effects of leaf traits on litter rainfall interception with consequences for runoff and soil conservation

Abstract During rainfall, plant litter interception regulates overland flow with an impact on water runoff generation and sediment displacement. Besides the rainfall characteristics, the effects of litter mass, thickness, storage and drainage properties on rainfall interception are reasonably well understood. In contrast, less is known about the influence of leaf traits, which we hypothesized to affect interception, soil hydrology and conservation via litter structure assembly. We measured the runoff and soil loss generation as determined by litter layer structural and hydraulic properties of 16 coexisting tropical woody species with wide‐range morphological leaf traits in a rainfall simulator experiment. Our results show that litter produced by coexisting species can differ in precipitation interception, thereby influencing runoff and soil loss. This is because there is important interspecific variation in litter water storage and drainage, which are negatively affected by leaf area (LA). Leaf water repellency positively affected litter water storage. Moreover, LA also negatively affected litter layer density. Litter density, in turn, increased runoff, but decreased soil loss, possibly due to protection against splash erosion. These results can be used to predict the effects of plant traits on the soil water balance and soil integrity protection through ecohydrological interception by the litter layer. The next research steps will be to extend our model to multiple‐species litter layers, and to validate and calibrate our model in different field situations in different ecosystems. Synthesis: We revealed the direct and indirect effects of species leaf size and hydraulic traits on litter rainfall interception, runoff and soil loss. We propose a new litter‐soil ecohydrological model, by using structural equation models, which can be used as a tool to predict ecosystem functioning, and guide management and restoration actions with water and soil conservation targets.

Evaluating Close-Range Photogrammetry for 3D Understory Fuel Characterization and Biomass Prediction in Pine Forests

Understory biomass plays an important role in forests, and explicit characterizations of live and dead understory vegetation are critical for wildland fuel characterization and to link understory vegetation to ecosystem processes. Current methods to accurately model understory fuel complexity in 3D rely on expensive and often inaccessible technologies. Structure-from-motion close-range photogrammetry, in which ordinary photographs or video stills are overlaid to generate point clouds, is promising as an alternative method to generate 3D models of fuels at a fraction of the cost of more traditional field surveys. In this study, we compared the performance of close-range photogrammetry with field sampling surveys to assess the utility of this alternative technique for quantifying understory fuel structure. Using a commercially available GoPro camera, we generated 3D point cloud models from video-derived image stills of 138 sampling plots across two western ponderosa pine and two southeastern slash pine sites. We directly compared structural metrics derived from the photogrammetry to those derived from field sampling, then evaluated predictive models of biomass calibrated by means of destructive sampling. Photogrammetry-derived measures of occupied volume and fuel height showed strong agreements with field sampling (Pearson’s R = 0.81 and 0.86, respectively). While we found weak relationships between photogrammetry metrics and biomass 0 to 10 cm in height, occupied volume and a novel metric to characterize the vertical profile of vegetation produced the strongest relationships with biomass above the litter layer (i.e., &gt;10 cm) across different fuel types (R2 = 0.55–0.76). The application of this technique has the potential to provide managers with an accessible option for inexpensive data collection and can lay the groundwork for the rapid collection of input datasets to train landscape-scale fuel models.

Succession of Fungal Communities and Their Functional Profiles in a Decaying Foundation Species.

Dead plant biomass from foundation plant species is fundamental for the survival of coastal salt marshes because dead biomass aids in the vertical accretion of the ecosystem. Fungi regulate the decomposition of dead biomass, and thus play an essential role for marsh survival. Despite their importance, little is known about the compositional and functional changes of fungal communities in plant matter throughout senescence and litter decomposition. Here, we analyzed how fungal communities and their functionality change in the foundation plant species Spartina patens, which builds vast amounts of dead plant biomass (thatch) on the soil surface. We analyzed the chemical and fungal properties of live biomass, standing dead biomass (dead biomass shortly after senescence), upper thatch (top layer of litter on the soil surface), and lower thatch (bottom layer of litter on the soil surface) during September and November of 2021. We found that the chemical and fungal properties of different S. patens biomass types followed a predictable litter decomposition pattern. Notably, live biomass, standing dead biomass, upper thatch, and lower thatch all hosted unique fungal communities and litter chemistry. Functional groups present in live biomass (pathogens, epiphytes, and mycoparasites) were lost during senescence and later replaced by diverse saprotrophs. The abundance of lignocellulose saprotrophs increased throughout decomposition, with the highest abundance occurring in lower thatch. These results suggest a predictable succession of fungal communities through the senescence and decomposition of the foundation species S. patens. Our study highlights the diversity of fungal communities in a disappearing foundation species.

Community structure of soil fauna under different tree species in subtropical forests

Soil fauna play an important role in key functions of ecosystem such as material cycling. Litter quality and microenvironment of different tree species may regulate soil fauna community structure. In this study, we investigated soil fauna community structure, the differences of taxonomic and functional groups, and the regulatory factors under eight dominant tree species in August 2022. We captured 567 soil fauna (except for termites and ants), belonging to 3 phyla, 10 classes, 26 orders, and 99 families, with Achipteriidae, Trygoniidae, Poduridae, and Isotomidae as the dominant species. Tree species significantly affected soil fauna abundance, following an order: Michelia macclurei > Elaeocarpus decipiens > Castanopsis carlesii > Cunninghamia lanceolata > Lindera communis > Schima superba > Pinus massoniana > Liquidambar formosana. However, the richness, evenness, and diversity of soil fauna under different tree species were significantly different. Richness and diversity of M. macclurei, C. lanceolatas soil fauna were relatively high, while L. formosana, C. carlesii were relatively low. The evenness of meso-microfauna of L. formosana was the highest, which was significantly higher than that of M. macclureis and E. decipiens. The evenness of macrofauna and total soil fauna was not significantly different among the eight tree species. In addition, the abundance of omnivores and herbivores soil fauna was relatively high under M. macclurei, but relatively low under E. decipiens. The abundance of saprophages and predators soil fauna of E. decipiens, M. macclurei was higher than L. formosana, while saprophages was mainly meso-microfauna. Results of redundancy analysis showed that litter N, C:N, and K were the main factors affecting soil fauna community structure. The results indicated that the tree species with thicker litter layer and higher N and K contents may be conducive to enhancing the diversity of soil fauna community and affecting the distribution of different functional groups, thus contributing to the maintenance of forest biodiversity.

Analisis Produksi Serasah Mangrove pada Hutan Mangrove Desa Kurau Timur, Kabupaten Bangka Tengah, Bangka Belitung

Mangrove forests have many ecological functions such as retaining and trapping sediments, dampening waves, providing protection for fish and other biota, and assimilating nutrients. Most of the nutrients returned to the forest floor are in the form of litter. Litter has an important role for the soil and the microorganisms in it. This study aims to measure the productivity of mangrove litter in the mangrove forest of Kurau Timur Village, Central Bangka Regency, Bangka Belitung. The method used to measure litter production is litter storage using a 1m x 1m litter trap with litter collection every 7 days for 3 months. Environmental parameter data analysis was performed by PCA (Principal Component Analysis). The rate of litter production in the mangrove forest of East Kurau Village is with a dry weight of 2.72 gr/m2/day. The components that make up litter are grouped into 3 components, namely leaves (66%), stems (18%), and flowers/fruits (16%). The litter layer on the mangrove forest floor of Kurau Timur Village is with an average dry weight of 69.02 grams, a water content of 40.73%, and an estimated average biomass of 3.08 tons/ha.

Seasonal Assessment of Biomass and Carbon Sequestration of Herbaceous Vegetation and Litter Layer in Homegarden Agroforestry System of Sam Higginbottom University of Agriculture, Technology and Sciences Campus, Prayagraj, India

An increase in greenhouse gases (GHGs) in the atmosphere, such as CO2, is what drives global warming. Strong carbon management is the first step in helping to stop climate change, safeguard human health, and create profitable businesses. A key strategy for lowering greenhouse gases emissions is carbon capture and storage. The study aimed to investigate the carbon sequestration potential of the herbaceous vegetation and litter layer in home garden agroforestry systems during the rainy season, winter season, and summer seasons in the SHUATS (Sam Higginbottom University of Agriculture, Technology and Sciences) Campus, Prayagraj. The total dry weight of the herbaceous layer and litter layer was measured, and the corresponding carbon sequestration values were calculated. During the rainy season, the herbaceous layer exhibited a total dry weight ranging from 0.31 kg m-2 to 0.36 kg m-2, resulting in carbon sequestration values ranging from 1.83 Mg C ha-1 to 2.13 Mg C ha-1. The litter layer had a total dry weight ranging from 0.13 kg m-2 to 0.16 kg m-2, contributing to carbon sequestration values ranging from 0.76 Mg C ha-1 to 0.92 Mg C ha-1.In the winter season, the herbaceous layer demonstrated a total dry weight ranging from 0.22 kg m-2 to 0.28 kg m-2, resulting in carbon sequestration values ranging from 1.29 Mg C ha-1 to 1.65 Mg C ha-1. Similarly, the litter layer exhibited a total dry weight ranging from 0.18 kg m-2 to 0.216 kg m-2, contributing to carbon sequestration values ranging from 1.05 Mg C ha-1 to 1.25 Mg C ha-1.During the summer season, the herbaceous layer displayed a total dry weight ranging from 0.303 kg m-2 to 0.361 kg m-2, resulting in carbon sequestration values ranging from 1.76 Mg C ha-1 to 2.10 Mg C ha-1. The litter layer had a total dry weight ranging from 0.16 kg m-2 to 0.24 kg m-2, contributing to carbon sequestration values ranging from 1.00 Mg C ha-1 to 1.32 Mg C ha-1. The results indicate that the herbaceous layer and litter layer of home garden agroforestry systems in the SHUATS Campus, Prayagraj, have the potential to sequester significant amounts of carbon during different seasons. This highlights the importance of home gardens in mitigating climate change and promoting sustainable land management practices.

Impacts of seasonality, drought, nitrogen fertilization, and litter on soil fluxes of biogenic volatile organic compounds in a Mediterranean forest

Biogenic volatile organic compounds (BVOCs) play critical roles in ecosystems at various scales, influencing above- and below-ground interactions and contributing to the atmospheric environment. Nonetheless, there is a lack of research on soil BVOC fluxes and their response to environmental changes. This study aimed to investigate the impact of drought, nitrogen (N) fertilization, and litter manipulation on soil BVOC fluxes in a Mediterranean forest. We assessed the effects of drought and N fertilization on soil BVOC exchanges and soil CO2 fluxes over two consecutive years using a dynamic chamber method, and solid-phase microextraction was utilized to quantify soil BVOCs in one year. Our findings revealed that the soil acted as an annual net sink for isoprenoids (1.30–10.33 μg m−2 h−1), with the highest uptake rates observed during summers (25.90 ± 9.36 μg m−2 h−1). The increased summer uptake can be attributed to the significant concentration gradient of BVOCs between atmosphere and soil. However, strong seasonal dynamics were observed, as the soil acted as a source of BVOCs in spring and autumn. The uptake rate of isoprenoids exhibited a significant positive correlation with soil temperature and atmospheric isoprenoid concentrations, while displaying a negative correlation with soil moisture and soil CO2 flux. The effects of drought and N fertilization on soil BVOCs were influenced by the type of VOCs, litter layer, and season. Specifically, drought significantly affected the exchange rate and quantities of sesquiterpenes. N fertilization led to increased emissions of specific BVOCs (α-pinene and camphene) due to the stimulation of litter emissions. These findings underscore the importance of the soil as a sink for atmospheric BVOCs in this dry Mediterranean ecosystem. Future drought conditions may significantly impact soil water content, resulting in drier soils throughout the year, which will profoundly affect the exchange of soil BVOCs between the soil and atmosphere.

Cadmium contamination in cacao farms of Piura, North Peru: A comprehensive assessment of geogenic and anthropogenic sources and implications for future production

Cadmium (Cd) is a heavy metal that poses a threat to food safety via the ingestion of food products with Cd. The uptake of Cd by the cacao tree (Theobroma cacao) has gained attention after the European Union set limits for Cd in chocolate products, the main commodity produced from cacao beans. In this study, we analyzed levels of Cd in soils and plant tissues across five cacao farms in the Piura region of Peru to identify the origins of Cd accumulation, and the natural and human factors controlling its concentration. Our results show that Cd levels varied in the order: leaves (1.25 mg kg−1) > beans (0.78 mg kg−1) > soils at 5 cm (0.68 mg kg−1) > soils at 20 cm (0.6 mg kg−1). Our findings suggest that the higher concentration of Cd in plant tissues and surface soils can be explained by readily available Cd from fertilizers and a litter layer being absorbed, cycled, and accumulated by the plant. Moreover, even when fertilizers are within regulatory limits, their continuous application, combined with the biocycling of Cd, may lead to high Cd concentrations in beans and leaves. Conversely, farms on alluvial soils and more stable topographic positions display higher soil and plant Cd concentrations. Likewise, farms located at lower altitudes, with higher contributing areas are more likely to receive Cd transported through sediments and water in the river network. Our results also suggest that variations in the underlying geology and soil mineralogy may be a source of potentially Cd bearing sediments. Overall, this study indicates that the high levels of Cd in plants in the study area are the result of a combined mechanism involving plant bioaccumulation and high Cd in fertilizers for the most part, with a minor contribution from potential Cd bearing minerals in sediments of alluvial soils.

Disparities in soil and water conservation functions among different forest types and implications for afforestation on the Loess Plateau

Afforestation is widely acknowledged as an effective approach for enhancing ecological conditions. Considering the challenging ecological environment on the Loess Plateau, prioritizing soil and water conservation functions in stands is crucial. The study aimed to ascertain the future development direction of forestry on the Loess Plateau by examining two representative forest types: planted forest (Robinia pseudoacacia pure forest and Pinus tabulaeformis pure forest), and natural secondary forest (a mixed forest of Quercus liaotungensis and Populus davidiana). The assessment centered on the soil and water conservation functions of the two forest types, encompassing the water conservation function (rainfall distribution and changes in multi-year soil moisture storage (0–200 cm)), soil conservation function (soil physicochemical properties), and understory plant diversity and stability. The results indicated that natural secondary forests outperformed planted forests in terms of water conservation function by effectively converting more precipitation into soil moisture, reducing runoff, and maintaining higher soil moisture storage. Additionally, natural secondary forests exhibited superior soil conservation functions compared to planted forests, characterized by higher soil porosity and nutrient properties. The variation in community structure between the shrub and herbaceous layers was more significant among different forests than within each forest (P < 0.05). Natural secondary forests exhibited higher understory shrub and herb biodiversity and interspecific repeatability compared to planted forests. Therefore, natural secondary forests are a more suitable forest type considering the natural conditions and silvicultural objectives of the Loess Plateau. To enhance the quality of afforestation, it is recommended to adopt near-natural planting patterns that replicate the environmental conditions of natural forests. For instance, actively creating mixed forests that emulate the tree species composition of natural forests and gradually reducing dependence on a single dominant tree species. Furthermore, the arborous and litter layers had a more direct and substantial influence on soil and water conservation functions compared to the shrub and herb layers. Foresters should prioritize regulating stand structure, such as increasing canopy variability, to enhance the water conservation function of stands. Additionally, they should actively protect the understory litter to fulfill its role in enhancing soil quality. This study provides a theoretical foundation and practical guidance for the implementation of vegetation restoration in ecologically vulnerable areas, such as the Loess Plateau.