Total Litterfall Research Articles

Relationship of litterfall anomalies with climatic anomalies in a mangrove swamp of the Yucatan Peninsula, Mexico.

Among the set of phenological traits featuring mangrove ecosystems, litterfall production stands out with marked intra-annual and longer-term variation. Furthermore, mangrove forests resilience is one of the most important ecological attribute, reconciling the juxtaposed terrestrial and marine environment such transitional systems occupy. However, world's mangroves are nowadays facing recurrent climatic events, reflected in anomalies depicted by major drivers, including temperature and precipitation. This physical-environmental setting may either constrain or favor overall forest productivity. A combination of time series analysis (spectral density and cross-correlation techniques) and statistical model fitting (General additive model) was implemented to explore trends in total litterfall of a well-developed mangrove forest in southeastern Gulf of Mexico (Celestun Lagoon, SE Mexico) and potential association with the varying behavior of temperature (°C) and precipitation (mm month-1), highlighting their anomalies. The results are consistent with a synchronous response between litterfall production and climatic variables (mean monthly temperature and total monthly precipitation). Concurrent peak litterfall production in Celestun lagoon with high temperatures and precipitation occurred during June and October, featuring a two-month time lag for the response time. More than half of the litterfall anomalies (53.5%) could be reflecting either multiple sources of climatic anomalies (maximum, minimum, and monthly average temperature and monthly total precipitation) or single point events (cyclone landfall). This relationship dynamics showed an interannual persistence (1999-2010). The structure portrayed by the litterfall time-series was not unequivocally related to climatic anomalies. Arguably, climatic anomalies behave with different intensities and even may exhibit complex interactions among them. The study of anomalies provides a baseline for a better grasp of: i) mangrove anomalies responses and ii) their vulnerability to these extremes.

Effects of rubber intercropping with native trees on litterfall and litter main nutrient return in Hainan Island, China

Understanding the process of litterfall production is crucial for sustainable development of plantations. However, the underlying dynamics of litterfall and its nutrient return in plantation agroforestry systems remain unclear. In this study, we investigated litterfall, including leaves, branches, flowers, and fruits, in three patterns: Hevea monoculture system (RM), Hevea–Michelia intercropping system (RAS1), and Hevea–Mytilaria intercropping system (RAS2) in Hainan Island, China. Our findings indicate that total litterfall was significantly higher in RAS1 (27,309 kg ha−1) and RAS2 (34,477 kg ha−1) than in RM (22,364 kg ha−1) and was predominantly composed of leaf litterfall in all three patterns, followed by branches, flowers, and fruits. The seasonal dynamics litterfall production of RM, RAS1, and RAS2 showed characteristic patterns. Litterfall nutrients exhibited peak and sub-peak monthly dynamics, peaking from February to March, during the dry season. Total nitrogen (TN), total phosphorus (TP), and total potassium (TK) content of annual litterfall in RAS1 significantly increased by 120 kg ha−1, 30 kg ha−1, and 139 kg ha−1, respectively, compared to those in RM, with percentage increases of 67.88%, 122.79% and 96.27%, respectively. Similarly, TN, TP, and TK content of annual litterfall in RAS2 significantly increased by 185 kg ha−1, 35 kg ha−1, and 170 kg ha−1, respectively, with percentage increases of 103.70%, 159.15% and 139.46%, respectively, for the abovementioned in RM. Litterfall showed a strong correlation with monthly average temperature, monthly minimum temperature, and monthly average wind speed, contributing 80.5%, 75.5%, 69.8%, and 69.6% to the total litterfall and its components, respectively. Further analysis indicated that monthly average temperature, monthly minimum temperature, and monthly average wind speed contributed 73.9%, 43.0%, and 66.6%, respectively, to TN, TP, and TK content of the annual litterfall, highlighting the significant influence of temperature and wind speed. These findings enhance our understanding of carbon and nutrient cycling and contribute to the sustainable management of tropical plantation ecosystems.

Climate drivers of litterfall biomass dynamics in three types of forest stands on the Loess Plateau

Litterfall is a link in the energy flow and material cycling of ecosystems, which maintain the primary productivity of forests. However, there is no consensus regarding the factors driving for the litterfall biomass dynamics because of the high spatial–temporal heterogeneity. Herein, we investigated and compared the stand litter biomass, litterfall biomass, including its components in the pure Robinia pseudoacacia forest (RL), pure Platycladus orientalis forest (PL), and mixed forest of Robinia pseudoacacia and Platycladus orientalis (ML) from 2020 to 2022 in the gully erosion area of the Loess Plateau. Correlation and multiple regression analyses were used to study the relationships among the amount of stand litter, litterfall biomass, and seasonal temperature and precipitation. Significant variation was found in the seasonal and annual litterfall biomass of the three types of forest stands. Annual stand litter biomass was in the order PL > RL > ML, whereas the annual litterfall biomass was in the order RL > ML > PL. The seasonal dynamics of litterfall biomass of twigs, leaf and fruits exhibited a ‘unimodal pattern’ with a peak in October. Annual leaf litterfall biomass formed, the main body of litter in all the components, accounting for 57.14–67.05 % of the total litterfall biomass. The correlation and regression analysis results showed that the stand litter biomass was primarily affected by the average temperature. Total litterfall biomass and twigs, leaf, and fruits were significantly affected by the precipitation and the maximum temperature, however, flower litterfall biomass was mainly affected by the average temperature. Overall, our results indicated that temperature plays a key role in the climatic factors affecting forest litterfall processes, while different climatic conditions and biological characteristics probably caused the differences in litterfall biomass. In the long term, temperature will potentially play a leading role in altering carbon storage and nutrient cycling as the climate warms.

Quarter century of mercury litterfall at a coniferous forest responding to climate change, Central Europe.

This work evaluated the 25-year-long trends (1994-2018) in mercury (Hg) concentrations and fluxes in spruce litterfall at a forest research plot Načetín (NAC) recovering from acidic deposition in the Ore Mountains, Czech Republic. The mean litterfall Hg deposition averaged 51 ± 18µgm-2year-1, which has been the highest litterfall Hg deposition reported up to date on the European continent. In contrast, the wet deposition (2017-2019) was an order of magnitude lower averaging at 2.5 ± 1.5µgm-2year-1. All the spruce litterfall components bark, twigs, needles, cones, and a mixture of unidentified fragments had elevated mean Hg concentrations relative to background sites averaging 256 ± 77, 234 ± 62, 119 ± 23, 95 ± 14, and 44 ± 15µg kg-1, respectively. Elevated litterfall Hg deposition and concentrations were attributed to the nearby local Hg emission source-coal-fired power plants. Temporally, the decrease of Czech Hg emissions since the 1990s was reflected by the decreasing trend of Hg concentrations in litterfall bark, cones, and twigs, while in needles and other material, Hg increased but insignificantly. Total litterfall ratios of Hg/C, Hg/N, and Hg/S were lower than those in soil O horizons averaging at 0.23 ± 0.04, 9.5 ± 2.0, and 170 ± 37μgg-1, respectively. Since the beginning of monitoring, total litterfall Hg/C exhibited no trend, Hg/N decreased, and Hg/S increased. The litterfall biomass deposition averaging at 469 ± 176gm-2year-1 increased through time resulting in an increased Hg litterfall deposition at NAC by 1.1µgm-2year-1 despite the decreases in Czech Hg emissions. Peaks of annual litterfall Hg deposition up to 96µgm-2year-1 at NAC during the 25years of monitoring resulted from weather extremes such as rime-snow accumulation, wind gusts, droughts, and insect infestation, which all significantly affected the annual biomass deposition. Based on our observations, further increases in biomass and litterfall Hg deposition rates can be expected due to the onset of bark beetle infestation and the increasing number of droughts caused by climate change.

Carbon and nutrient cycling in cocoa agroforests under organic and conventional management

In cocoa agroforestry systems, cycling of leaves, pods, and branches are key for organic matter sustenance. We investigated annual total litterfall, annual nutrient stocks in total litterfall, cocoa pods and beans, as well as cocoa leaf decomposition rates in cocoa agroforestry systems under conventional and organic management in Suhum Municipality, Eastern Region of Ghana. The study was conducted using six cocoa agroforests for each management selected from a total of four villages. Litterfall was collected monthly using litterboxes and a litterbag technique was employed to study the rates of leaf decomposition and nutrient release for 12 months. In June and July, total litterfall in organic farms were 94% and 65%, respectively, higher than in conventional farms, but management had no effect on average annual total litterfall of 8.8 t ha−1 yr−1 litterfall. Due to the trees’ reduced transpiration, 61% of the annual total litterfall occurred during the dry season. Whereas average leaf litter nitrogen (N) concentration was 17% higher in the rainy season than dry season, potassium (K) concentration was 38% higher during the dry season than rainy season. This likely reflected the contribution of N rich green leaves to litterfall in the rainy season and plant coping strategy to drought leading to K accumulation. Cocoa leaf decomposition was not affected by management. Annual potassium (K) and calcium (Ca) stocks in cocoa pod husk were four and nine-fold, respectively, higher than in cocoa beans. We conclude that organic versus conventional management had no effect on litterfall and cocoa leaf decomposition rather season influenced litterfall quantity and chemistry. Irrespective of management the spreading of cocoa pod husk after harvest will improve internal nutrient cycling in cocoa agroforestry systems.

Seasonal and long-term changes in litterfall production and litter decomposition in the dominant forest communities of Western Himalaya

Understanding changes in litter fall is paramount for effective management, as it directly impacts ecosystem health, nutrient cycling, and overall biodiversity. It informs strategies for conservation, land use planning, and mitigating ecological disruptions. Therefore, present study investigates the seasonal and long-term changes in litterfall dynamics within the dominant forest communities of Western Himalaya. A total four distinct forest ecosystems, including Sal, (Shorea. robusta) Chir-pine (Pinus roxburghii), Banj-oak (Quercus leucotrichophora), and Mixed-oak (Q. leucotrichophora, Q. floribunda and Q. lanuginosa) forests were selected for the study. The total annual litter production across the forest stands varied from 741.59 to 841.22 g−2, with the highest recorded in the Banj-oak stand (841.22 g−2) and the lowest in the Sal stand (741.59 g−2). Leaf fall reported for the highest proportion of total litterfall (64.88% to 71%) across the forest stands, and peak litterfall was observed during the summer months in all forest sites. The leaf litter decomposition rate of selected species shows significant variation (F5, 10 = 3.41, p < 0.05) between species. Interestingly, litterfall production increased in all forest sites from 1980 to 82 to 2017–19. However, no significant changes were observed in the decomposition rate. The findings reveal significant variations in litterfall dynamics across different forest ecosystems, with leaf fall contributing substantially to total litter production. The observed increase in litterfall production over the studied period highlights the need for continued monitoring and adaptive management strategies to address potential ecological implications. These insights are invaluable for informing conservation efforts, land use planning, and mitigation strategies aimed at preserving ecosystem health, sustaining biodiversity, and ensuring the long-term resilience of Western Himalayan forests in the face of environmental change.

Climatic drivers of litterfall production and its components in two subtropical forests in South China: A 14-year observation

Understanding the climatic triggers of litterfall production is essential for simulating nutrient cycling in forest ecosystems. However, the mechanisms underlying litterfall dynamics in subtropical forests remain unclear because of the complex canopy phenological strategies. Herein, we explored this by investigating a unique litterfall dataset (including components such as leaves, branches, flowers and fruits, and miscellaneous, etc.) spanning a 14-year observation period (2005–2018) in two typical subtropical evergreen forest ecosystems in South China: a mixed conifer-broadleaf forest (MF) and a monsoon evergreen broadleaved forest (MEBF). We found that the annual total litterfall production, often dominated by leaf litterfall, was significantly higher in MF (10.21 ± 2.09 t∙hm−2) than in MEBF (7.74 ± 2.21 t∙hm−2) (P < 0.01). Generally, forest litterfall production occurred mostly during the wet season and was profoundly correlated with the monthly maximum wind speed (rMF = 0.70, rMEBF = 0.71, P < 0.01), it contributed exceeded 80% to the total litterfall and the leaf and branch components. Whereas during the dry season, the forest litterfall process was dramatically weakened, showing a significant correlation with the mean temperature (rMF = 0.48, rMEBF = 0.68, P < 0.01). Further analysis showed that during the dry season, the cumulative contribution rates of temperature factors to the total litterfall and the leaf and branch components exceeded 60%, indicating a leading role of temperature in triggering forest litterfall processes. Notably, when excluding the typhoon disturbances, it is observed that temperature, alongside wind speed, emerges as a significant determinant of forest litterfall production during the wet season. Those two factors collectively account for almost 60% of the total litterfall and the leaf and branch components. Our findings have potential significance in improving our understanding of carbon and nutrient cycling in subtropical forest ecosystems under climate change conditions.

Litterfall and element fluxes in secondary successional forests of South Korea

Determining litterfall and corresponding element fluxes is valuable in understanding productivity and biogeochemical cycling in floristically distinct secondary successional zones. Secondary-growth forests form a major portion of the cool-temperate forests of South Korea following decades of severe disturbance and intensive rehabilitation efforts. This study monitored the total and fraction-specific litterfall mass, element flux, and nutrient use efficiency patterns of a secondary-growth broadleaf deciduous forest (hereafter, BDFA) and compared these values in forests with contrasting sub-canopy compositions (BDFB) and with coniferous evergreen forests (CEF). Mean annual total litterfall mass was uniform across stands at a range of 871.5 g m−2 yr−1 to 990.2 g m−2 yr−1. Litterfall mass of seed, bark, and miscellaneous fractions varied per stand (p < 0.05 for seed; p < 0.01 for bark and miscellaneous). A pronounced unimodal litterfall peak was detected for all stands, with total litterfall responding positively to relative humidity but negatively to windspeed and solar radiation. Coniferous evergreen litter contained higher C but lower macronutrients relative to broadleaf deciduous litter. Macronutrient fluxes ranged from 156.2 to 183.9 kg ha−1 yr−1, with broadleaf stands having significantly higher K and Ca rates. Macronutrients were returned in all stands in the order of N > Ca > K > Mg > P, whereas NUE followed a reverse sequence. NUE in CEF was higher than BDFA and BDFB for all macronutrients, reflecting the distinct biomass allocation and nutrient utilization strategies between conifers and broadleaves. In temperate secondary-growth forests, nutrient cycling via litterfall is substantiated primarily by litterfall quantity and secondarily by litter element concentration. Our findings have important implications for elucidating forest litter ecology and improving sustainable management practices in secondary successional forests.

Litter dynamics of forest ecosystem in an urban and pristine area of West Bengal, India

Aim: A comparative assessment of forest litterfall dynamics was carried out between the Garadaha forest (GF or urban) and the Pratappur forest (PF or pristine), located in Burdwan districts of West Bengal, and the litterfall components were correlated with the environmental factors that govern the dynamics. Methodology: Nets of dimension 1m × 1m were placed below the tress of both forests and litter was collected at regular intervals per month and brought to the laboratory for separation into the categories like leaf litter, woody litter (bark), miscellaneous (mixed) and twig. Two types of litterfall such as specific litterfall and standing litterfall were calculated. Environmental factors such as maximum and minimum temperature, rainfall, relative humidity, wind speed, solar irradiance, and photosynthetically active radiation (PAR) were studied simultaneously followed by correlation and Principal Component Analysis. Results: Pre-monsoon showed the highest total litterfall (specific litterfall and standing litterfall) in both types of forests. The decomposition quotient was higher in the pristine forest than in the urban forest. The correlation between litterfall components and environmental factors showed that solar irradiance was positively correlated with litterfall dynamics. Interpretation: The work emphasizes the forest management of urban areas impacted by industrialization and urbanization. The anthropogenic causes influence the plant growth and litterfall pattern thereby affecting the decomposition process and soil health. The selection of proper tree species should be given priority for social forestry in industrialized zones of India. Key words: Litter decomposition, Seasonal pattern, Solar irradiance, Standing litter, Temperature

Nutrient cycling aspects as possible ecosystem functional indicators of successional stage in Semideciduous seasonal forest, Rio de Janeiro state, Brazil

Semideciduous Seasonal Forest is a phytophysiognomy of Atlantic Forest with high plant richness but low representativeness in few remnants areas in different successional stages. The assessment of the degree of conservation of those areas helps to indicate whether there is a need for taking strategies to favor forest succession. Thus, the aim of this study was to identify litterfall and its nutrient content, accumulated litter biomass on topsoil, leaf litter decomposition, and topsoil (0–10 cm) chemical attributes as possible indicators of successional stages in areas of Seasonally Semideciduous Forest. We collected available information in literature on CAPES Portal and Google Scholar (May/2021 to February/2022) for Pinheiral municipality, State of Rio de Janeiro, Brazil, which were evaluated by multivariate analysis. Accumulated litter biomass, nutrient content (N, P, K) in total litterfall, pH and P availability in topsoil, leaf litter decomposition constant, and half-life time of leaf litter were the most sensitive attributes to indicate the successional stage in the study area, according to Principal Component Analysis. This multivariate analysis indicated that areas in early successional stage were associated with higher values of leaves contribution, half-life of leaf litterfall, contents of Ca and K in total litterfall, whereas areas in middle successional stage were associated with higher values of pH, total organic carbon, exchangeable Ca2+, K+, and Mg+, sum of bases and cation exchange capacity, and lower values of extractable acidity and exchangeable Al3+ in the topsoil. Areas in advanced stages of succession were associated to higher values of total litterfall and its nutrient content (N, K, Mg), accumulated litter biomass, available P in topsoil, and leaf litter decomposition constant. The Cluster multivariate analysis revealed that the areas in advanced successional stage presented high dissimilarity in relation to the areas in early and middle successional stage.

Litterfall and nutrient transfer dynamics in a successional gradient of tropical dry forest in Colombia

Introduction: The litterfall production, foliar nutrient dynamics and decomposition are essential to maintain nutrient cycling, soil fertility, and carbon regulation in terrestrial ecosystems. With several studies addressing the variation of these processes, their dynamics in tropical dry forests (TDFs) remain unclear, due to its complex interaction of biotic and abiotic factors. Objective: To evaluate litterfall, nutrient potential return and use efficiency, and decomposition variation in a TDF successional gradient in Tolima, Colombia. Methods: We quantified litterfall from November 2017 to October 2019 in 12 plots distributed in four successional stages: initial, early, intermediate, and late forests. We identified key tree species in foliar litter production and characterized the foliar decomposition of these species. At the community level, we quantified the C, N and P potential return, the N and P use efficiency, and the C:N and N:P ratio. Subsequently, we analyze relationships between vegetation characteristics and some soil chemical properties with these ecological processes. Results: We found that total litterfall in late forests (8.46 Mg ha-1 y-1) was double that found in initial forests (4.45 Mg ha-1 y-1). Decomposition was higher in initial (k = 1.28) compared to intermediate (k = 0.97) and late forests (k = 0.87). The nutrient potential return didn’t change along succession, but it did show differences between study sites. The structural development and species richness favored litterfall, while soil chemical conditions influenced nutrient returns and decomposition. Conclusions: TDFs could recover key ecosystem function related to litterfall and nutrient dynamics after disturbances cessation; however, the soil quality is fundamental in return and release of nutrients.

Dynamics of litterfall production in a forest damaged by oak wilt disease: a case study in a warm-temperate secondary forest

ABSTRACT Quantification of litterfall production is crucial for evaluating net primary productivity and nutrient cycling in forest ecosystems. High mortality among trees in the family Fagaceae due to Japanese oak wilt disease (JOW) might affect litterfall production in secondary forests; however, few studies have quantified these effects. We investigated litterfall production and forest structure in warm-temperate secondary forests in the Kaisho Forest over 6 and 12 years, respectively, and compared the dynamics among different phases of a JOW outbreak to assess the impacts of JOW on litterfall production. We found that total annual litterfall and leaf fall showed little change in peak to post-JOW periods and that changes in basal area were unrelated to total litterfall and leaf fall. The observed fluctuation in BA in the Kaisho Forest may not have been large enough to clearly reveal the effect of JOW during these periods. Canopy gaps formed by JOW may enhance the recruitment and growth rates of sub-canopy and understory trees. Our results may only be applicable to warm secondary forests where evergreen trees are replacing deciduous trees. Additional information on litterfall production in JOW-disturbed secondary forests is needed.

Total litterfall and leaf-litter decomposition of Theobroma grandiflorum under different agroforestry systems in the western Colombian Amazon

Total litterfall and leaf-litter decomposition of Theobroma grandiflorum under different agroforestry systems in the western Colombian Amazon

Effects of Thinning on Litterfall Production and Leaf Litter Decomposition Rates of Karacabey Forested Wetlands, Bursa, Turkiye

The contribution of litterfall (dead leaves, twigs, etc., fallen to the ground) and forest floor (organic residues such as leaves, twigs, etc., in various stages of decomposition, on the top of the mineral soil) is fundamental in both forest ecosystem sustainability and soil greenhouse gases (GHG) exchange system with the atmosphere. A focus on forested wetlands is particularly important, as these systems account for a disproportionate amount of global carbon flux relative to their spatial coverage, and the decomposition of leaf litter is a major contributor. In this study, we aimed to investigate the effects of two different thinning treatments (low thinning-canopy closure 41-70% and intense thinning-canopy closure 10-40%) on litterfall, forest floor litter and leaf litter decomposition rates of alder (Alnus glutinosa) stands in Karacabey forested wetlands. The litterfall was monthly collected using open litterfall traps for 2 years from 2021 to 2022. The forest floor litter was also sampled 50 x 50 cm2 quadrates of 5 points in research plots of 20×20 m. The differences in leaf litter decomposition rates between the low and intense thinning stands were investigated using the litterbag method in the field for 18 months. The results indicated that the intense thinning significantly reduced the total litterfall production (7.24 ± 0.384 Mg ha-1) and the forest floor litter (2.78 ± 0.41 Mg ha-1) compared to the low thinning stand (10.8 ± 0.527 Mg ha-1 and (4.38 ± 0.82 Mg ha-1 respectively). Lower leaf litter decomposition rates were also seen in the intense thinning stands than in the lower thinning stands. At the end of the 18 months, the leaf litter mass loss was 83.6% in the intense thinning stands compared to the lower thinning stands (88.3%).

Nutrient fluxes via litterfall in silver birch (Betula pendula Roth) stands growing on post-arable soils

The purpose of this study was to evaluate the importance of litterfall as a link in biogeochemical cycling of certain elements (C, N, P, K, Ca, Mg, Fe, Mn, Cu, and Zn) in silver birch stands growing on post-arable soils under temperate climatic conditions (Poland). The study covered three stands on sandy soils (21, 29, and 40 years old) and three on loamy soils (15, 33, and 41 years old). Litterfall was collected during 2020–2021 and analysed using standard procedures. Elemental contents were determined also in green leaves collected from the tree crowns in early summer to determine intensity of retranslocation. The total litterfall production varied from 2576 to 5293 kg ha−1, depending on the stand and year. These values are typical of temperate forests. Litterfall production was positively correlated with stand age. Leaves made up the major fraction, followed by twigs. Silver birch litterfall was generally rich in nutrients compared to many other tree species typical for temperate climatic zone. Nutrient fluxes to the soil were in the upper limits reported in the literature. It may partially be an effect of the post-arable history of these stands. Large fluxes of nutrients to the soil via litterfall are important in the context of the high nutritional demands of the studied tree species. This study also showed that silver birch strongly retranslocates N, P, and K from senescing leaves, whereas Ca, Mg, Fe, Mn, Cu, and Zn are accumulated in these organs.

Struktur Vegetasi Mangrove dan Produksi Serasah Mangrove Sonneratia alba di Telaga Wasti Kabupaten Manokwari, Papua Barat

The productivity of mangrove litterfall is the most important part of the transfer of organic materials from mangrove vegetation into the waters and soils. This research was conducted in July-August 2021 in three stations on mangrove ecosystem at Wasti Lake, Manokwari Regency. The purpose of this study was to determine the mangrove vegetation, litterfall production of Sonneratia alba, relation of Diameter at Breast High with litterfall production, and physical chemistry of the environment. The quadrant transect was used to sample mangrove vegetation and the litter trap to measure litter production. The results showed 5 types of mangroves, namely Sonneratia alba, Rhizophora stylosa, Rhizophora apiculata, Bruguiera gymnorrhiza, and Bruguiera sexangua. The highest density values ​​at each station was Sonneratia alba, namely 360 ind/ha, 540 ind/ha and 520 ind/ha with important value indexes are 268.08%, 255.59%, and 247.96%. The total litterfall production of Sonneratia alba during a period of 28 days was 79.19 gr/m². The highest litter contribution components came from leaves (87.6%), twigs (8.1%), and flowers (4.3%). Correlation and regression analysis showed a very strong positive relationship between DBH and litter production. The environmental parameter values ​​for DO ranged from 6.2-8.4 mg/L, water temperature 28.7 – 35.6⁰C, pH ranged from 7.06 – 7.47, salinity 25 – 27.5, substrate pH 6.1 – 6.3, the air temperature is 29-32⁰C, and the humidity is 70-80%.

Hail-caused greenfall leaves, litterfall, nutrients, and leaf decomposition in tropical cloud forest and a restoration planting

Abstract Greenfall leaves caused by hailstorms may represent a resource pulse of nutrients. We determined the contribution of greenfall versus senescent leaves to total litterfall production, carbon, nitrogen and phosphorus input to the system, and leaf decomposition rate. Litterfall was collected monthly for three years in two cloud forests (F1, F2) and a restoration planting area (R) in Veracruz, Mexico. Two fortuitous hailstorms occurred in the second year. Leaf decomposition rate was determined in all three sites but did not differ across them. Total annual litterfall, excluding greenfall, was 10.0, 10.1, and 7.7 Mg ha−1 y−1 for F1, F2, and R, respectively. Senescent leaves represented 65% of the litterfall, while greenfall leaves increased the annual leaf biomass component of the litterfall by 12%. Concentrations of carbon, nitrogen, and phosphorus were 2.3, 5.7, and 18.1% higher, respectively, in greenfall than in senescent leaves. Greenfall increased the annual input of C, N, and P by 12, 13, and 14%, respectively. Despite their short duration (approximately 70 minutes), the hailstorm events generated a substantial contribution of greenfall leaves and a source of extra C, N, and P, since these leaves decompose and are incorporated into the cloud forest system.

Differential Impacts of Acacia Invasion on Nutrient Fluxes in Two Distinct Bornean Lowland Tropical Rain Forests

Invasive Acacia species can alter nutrient cycling processes in forest ecosystems, particularly affecting total litterfall production and litter decomposition patterns. This study examined the effects of exotic Acacia mangium Willd. on total litterfall production, nutrient concentrations in leaf litterfall fractions, leaf litter decomposition, and nutrient release in lowland heath (HF) and mixed dipterocarp forests (MDF) in Brunei Darussalam, Borneo. Above-ground litterfall traps were installed in HF and MDF with and without invasive Acacia present, representing four habitat types in total, and monthly collections were conducted for 12 months. Litter decomposition bags were deployed to determine the rates of decomposition and nutrient release. Habitats invaded by Acacia exhibited higher total litterfall production, increased leaf litter concentrations of nitrogen, potassium, and calcium, and increased addition of all nutrients measured in litter (nitrogen, phosphorus, potassium, calcium, and magnesium, especially in the Acacia-invaded mixed dipterocarp forest (AMDF) and nitrogen and potassium in Acacia-invaded heath forest (AHF)), reduced nitrogen and potassium use efficiencies in AHF, and reduced stand-level nitrogen and calcium use efficiencies in AMDF. Litter decomposition rates and nutrient release were lower in AMDF than in the three other habitats. The significantly higher total litterfall production coupled with higher nutrient addition in the two Acacia-invaded habitats is expected to progressively increase the abilities of these habitats to produce large quantities of nutrient-rich litter and will likely eventually lead to an enrichment of nutrients in the soil, thus facilitating further invasion by Acacia, particularly in the MDF.

Effect of Tree Leaf Litterfall on available Nutrients and Organic Carbon Pools of Soil

A study was conducted to investigate the effect of leaf litterfall of shelterbelt, Azadirachta indica, Ailanthus excels and Prosopis cineraria and control (devoid of trees) on available nutrients and organic carbon pools of soil from 3 distances (2, 5 and 10m) The total litterfall during the study period ranged between 1712 and 4126kg/ha and it was found maximum in the month of January and it was minimum in February in different plantations. Annual litterfall showed considerable variation among different plantations. Litter accumulation under the different plantations canopy was highest in the shelterbelt followed by Prosopis cineraria and lowest in the Azadirachta indica. There was improvement in soil organic carbon, dissolved organic carbon, microbial biomass carbon, available macro (N, P and K) and micronutrients (Zn, Fe, Mn and Cu) tree species when compared to field without trees. Significant improvement in soil organic carbon (0.14 to 0.26 %), available N (55.9 to 116.6kg/ha) P (9.6 to 13.6kg/ha) and K (188.9 to 248.3kg/ha) was observed under these tree species compared to field without trees. The content of Zn, Cu, Fe and Mn and was 15, 25, 40 and 51 percent, respectively higher under these tree species than the control field. The amount of nutrients returned to the soils through litter was significantly highest at 2m distance under different plantations. The present study indicated that these available nutrients and organic carbon pools improved significantly across the different land use system. Due to intensive cultivation and monocropping, the fertility of soil is deteriorating day by day. Simultaneously it is creating a pressure on the natural resources like soil because the population is increasing day by day. Therefore, it is wise to use degraded and problematic soil for cultivation. Agroforestry systems have been recognized as an alternative for the rehabilitation of degraded areas and it provides ecosystem services and reduces human impacts on natural forests (Nair et al., 2009). Tree based land use systems have special role in reclamation of wastelands, use of poor-quality waters, organic carbon build up and moderating climate change related risks. In areas of Haryana and Rajasthan trees like Prosopis cineraria, Azadirachta indica and Ailanthus excels are more beneficial under adverse environments due to their drought hardiness, resistance to inhospitable climate and assured economic returns. These tree species can be grown on soils having poor fertility, moisture deficit and high soil temperature.

Effects of Two Management Practices on Monthly Litterfall in a Cypress Plantation

Optimizing stand structure can enhance plantation forest ecosystem service functions by regulating litterfall patterns; however, the effects of close-to-nature management on litterfall production remain unclear. Here, we selected three cypress (Cupressus funebris) plantations, including one using the practice of strip filling (SF), one using the practice of ecological thinning (ET), and one pure cypress plantation without any artificial interference. The production of total litterfall and its components (leaf, twig, reproductive organ and miscellaneous litterfall) were investigated monthly over one year from September 2019 to August 2020. Compared with that of the pure plantation, the total annual litterfall production of the SF and ET plantations decreased significantly by 10.8% and 36.44%, respectively. The annual production of leaf and reproductive organ litter was similar to that of total litterfall, but that of twig and miscellaneous litter was higher in the SF and ET plantations than in the pure plantation. Moreover, total, leaf and reproductive organ litterfall production displayed unimodal dynamics regardless of plantation, although the peaks of reproductive organ litter production occurred in different months. In contrast, the production of twig litter showed bimodal dynamics in the pure plantation, while unimodal and irregular dynamics were observed in the plantations with ET and SF, respectively. Additionally, insignificant differences in the isometric growth index of leaf litter and total litterfall were observed. The allometric indices of twig litterfall versus total litterfall, reproductive organ litterfall versus total litterfall, and leaf litterfall versus twig litterfall were higher in the plantations with SF and ET than in the pure plantation. Redundancy analysis (RDA) revealed that diameter at breast height and air temperature were the most important factors shaping the annual and monthly production of litterfall, respectively. These results provide efficient data to support the rectification of the material circulation of cypress plantations and their future management.