Litter Production Research Articles

English

A study was conducted in the Guinea and Sudan Savannah zones in the Upper East Region of Ghana to investigate the effects of Faidherbia albida on some important soil fertility indicators. Soil sampling and analysis, litter trap, and litter bag techniques were employed to determine the soil’s content of major nutrients, the rate of litterfall production and litter decomposition, respectively. Analysis of variance (ANOVA) was performed to determine differences among treatment means, while Tukey’s highest significant difference (HSD) was used to perform post hoc tests among means within the same sample set. Soils under F. albida tree canopies were found to contain significantly higher organic carbon and total nitrogen than those outside the canopies. Peak leaf litter production occurred during the first three months of the onset of the rainy season. Annual leaf litterfall was 340 g m-2 year-1 in the Guinea Savannah zone and 264 g m-2 year-1 in the Sudan Savannah zone. The high leaf litterfall, followed by high decomposition and mineralization at the beginning of the cropping season, the high nutrient content of its leaves, coupled with its nitrogen fixing ability, make F. albida a potential candidate for soil improvement and improved productivity of major crops in smallholder farming systems. About 37 and 59 adult F. albida trees will be required to supply significant amounts of nitrogen in the Guinea and Sudan Savannah zones, respectively. Key words: Litter bag technique, litter decomposition, litter fall, litter trap technique, soil organic carbon, soil

Leaf litter inputs reinforce islands of nitrogen fertility in a lowland tropical forest

The role of lowland tropical forest tree communities in shaping soil nutrient cycling has been challenging to elucidate in the face of high species diversity. Previously, we showed that differences in tree species composition and canopy foliar nitrogen (N) concentrations correlated with differences in soil N availability in a mature Costa Rican rainforest. Here, we investigate potential mechanisms explaining this correlation. We used imaging spectroscopy to identify study plots containing 10–20 canopy trees with either high or low mean canopy N relative to the landscape mean. Plots were restricted to an uplifted terrace with relatively uniform parent material and climate. In order to assess whether canopy and soil N could be linked by litterfall inputs, we tracked litter production in the plots and measured rates of litter decay and the carbon and N content of leaf litter and leaf litter leachate. We also compared the abundance of putative N fixing trees and rates of free-living N fixation as well as soil pH, texture, cation exchange capacity, and topographic curvature to assess whether biological N fixation and/or soil properties could account for differences in soil N that were, in turn, imprinted on the canopy. We found no evidence of differences in legume communities, free-living N fixation, or abiotic properties. However, soils beneath high canopy N assemblages received ~ 60% more N via leaf litterfall due to variability in litter N content between plot types. The correlation of N in canopy leaves, leaf litter, and soil suggests that, under similar abiotic conditions, litterfall-mediated feedbacks can help maintain soil N differences among tropical tree assemblages in this diverse tropical forest.

Litterfall Pattern and Nutrient Dynamics of <i>Swietenia macrophylla</i> (King) Plantation In Terai Region, West Bengal, India

The present study focuses the litter fall production, pattern and nutrient dynamics under Swietenia macrophylla plantation in Terai region of West Bengal, India. The total litter production was 6920.2 kg ha -1 yr -1 and 8387 kg ha -1 yr -1 in 2016-17 and 2017-18 respectively. The increase in annual total litter production in 2017-18 was 17% higher than the year 2016-17. It was observed that leaf litter showed higher nutrients than that of rachis litter. The leaf fraction had the highest amount of nutrient in the decreasing order of N > K > S > P whereas the same trend was followed in rachis litter. The nitrogen return of 92.98 kg ha -1 and 12.14 kg ha -1 was recorded in leaf and rachis, respectively whereas the return of phosphorous was 7.95 kg ha -1 and 1.08 kg ha -1 . Similarly, the potassium nutrient return was 58.73 kg ha -1 and 8.30 kg ha -1 and the return of sulphur nutrient was 19.58 kg ha -1 and 1.38 kg ha -1 in leaf and rachis, respectively.

Low and High Nitrogen Deposition Rates in Northern Coniferous Forests Have Different Impacts on Aboveground Litter Production, Soil Respiration, and Soil Carbon Stocks

Nitrogen (N) deposition can change the carbon (C) sink of northern coniferous forests by changing the balance between net primary production and soil respiration. We used a field experiment in an N poor Pinus sylvestris forest where five levels of N (0, 3, 6, 12, and 50 kg N ha−1 yr−1, n = 6) had been added annually for 12–13 years to investigate how litter C inputs and soil respiration, divided into its autotrophic and heterotrophic sources, respond to different rates of N input, and its subsequent effect on soil C storage. The highest N addition rate (50 kg N ha−1 yr−1) stimulated soil C accumulation in the organic layer by 22.3 kg C kg−1 N added, increased litter inputs by 46%, and decreased soil respiration per mass unit of soil C by 31.2%, mainly by decreasing autotrophic respiration. Lower N addition rates (≤ 12 kg N ha−1 yr−1) had no effect on litter inputs or soil respiration. These results support previous studies reporting on increased litter inputs coupled to impeded soil C mineralization, contributing to enhancing the soil C sink when N is supplied at high rates, but add observations for lower N addition rates more realistic for N deposition. In doing so, we show that litter production in N poor northern coniferous forests can be relatively unresponsive to low N deposition levels, that stimulation of microbial activity at low N additions is unlikely to reduce the soil C sink, and that high levels of N deposition enhance the soil C sink by increasing litter inputs and decreasing soil respiration.

Litter dynamics, leaf area index and forest floor respiration as indicators for understanding the role of Nepalese alder in white oak forests in central Himalaya, India

Abstract The present study is an attempt to understand the role of Nepalese alder (Alnus nepalensis D. Don) in litter production, leaf litter decomposition, leaf area index (LAI) and rate of forest floor respiration as indicators of carbon flux in white oak (Quercus leucotrichophora A. Camus) forests. Five forest stands of oak mixed alder (OMA) and five oak without alder (OWA) were selected along a basal area gradient under similar ecological conditions in Indian central Himalaya. We estimated monthly variations in litterfall, leaf litter decomposition and leaf area index (LAI) in Q. leucotrichophora and A. nepalensis in OMA and OWA stands. Soil and litter CO2 effluxes were estimated seasonally using the soda-lime absorption method. The seasonal pattern of litterfall showed a bimodal trend in OMA and unimodal trend in OWA forest stands. Forest floor biomass (leaf, twig, reproductive parts, herbaceous and miscellaneous litter) was highest in summer (707–1080 g/m2) followed by winter (414–678 g/m2) and rainy (281–541 g/m2) seasons in OMA stands. In OWA stands, forest floor biomass was highest in summer (463–646 g/m2) followed by rainy (321–411 g/m2) and winter (149–279 g/m2) seasons. Total litter production, leaf litter decomposition rates, change in LAI and soil respiration were significantly higher (p

Species identity improves soil respiration predictions in a semiarid scrubland

Soil respiration accounts for ca. three quarters of total ecosystem respiration and is sensitive to temperature and moisture. Plants can influence soil CO2 emissions through specific effects on soil humidity, soil temperature and soil microbial communities. These plant-soil effects mostly come via litter production and root exudates, enhancing soil autotrophic and heterotrophic respiration. We explored how plant species affected soil CO2 emissions in an arid environment. We altered soil temperature in bare soil and under the canopy of four plant species differing in functional type, and measured monthly fluxes to establish seasonal patterns of CO2 release along a 20-month period. We found that soil temperature explained 69% of the annual soil respiration (SR) variance, while soil water content explained 71% of SR variance. When we included plant species identity in the model, soil temperature and soil water content explained 76% and 81% of SR variance, respectively, exemplifying how plant species modulate SR responses as a function of temperature and water availability. Our results demonstrate that plant species influence soil carbon balance and emphasize that species identity matters in dry ecosystems. SR dynamics in dry ecosystems can be accurately modelled with soil water and temperature as predictors, but models are more efficient if plant species identity is considered.

Annual litter production in a Brazilian Cerrado woodland savanna

The Brazilian Cerrado is a heterogeneous ecosystem where annual woody-layer litter production shows strong spatiotemporal variation. Although Cerrado litter dynamics have been well-documented in forest physiognomies, knowledge from savanna habitats remains limited despite their predominance across the landscape. In this study, the fine-woody litter production and their fractions were quantified throughout the year in an area covered by the cerrado denso physiognomy (a woodland savanna) at Panga Ecological Reserve, Minas Gerais, Brazil. Using ten litter traps distributed along a 250 m transect, it was estimated that 4.44 Mg ha–1 of litter was produced annually in the cerrado denso, with leaves representing the greatest fraction (75.9%), followed by small woods (11.9%), reproductive parts (8.8%) and miscellaneous items (3.4%). Litterfall varied strongly throughout the year (monthly range: 0.17 to 1.01 Mg ha–1), and although the contribution of different fractions also varied monthly, leaves were dominant through most of the year (range: 34–94%). In fact, there was a strong positive relationship between leaf-litter biomass and the total amount of litter produced. The estimate falls within the previously recorded litter production range for the Cerrado and corresponds numerically to the position occupied by the cerrado denso physiognomy in the structural vegetation gradient in this biome. Furthermore, results indicated that litterfall in this physiognomy is strongly seasonal. Leaves represented the major part of accumulated biomass and were responsible for the increased dry season production when most woody species concentrated their leaf shedding. These results aid the understanding of the functioning of Cerrado ecosystems, and determining litterfall patterns for the entire vegetation mosaic of physiognomies is essential for the implementation of quantifiable environmental quality diagnoses and evaluations of anthropic impacts.

Productivity and decomposition rate of Rhizophora mucronata and Avicennia alba litter based on environment characteristics in Muara Gembong

Mangrove forests damage may decrease their function and ecological role in relation to litter production which support the sustenance of aquatic resources. This research aimed to determine and estimate productivity and decomposition rate of mangrove Rhizophora mucronata and Avicennia alba litter, and their effect on water nutrients. The research was conducted at three stations in Pantai Mekar Village, Muara Gembong District for 60 days observation during period of April–September 2018. Litter productivity was measured using litter traps and litter decomposition rate was estimated using litter bags. The concentration of water nutrient (nitrate, ammonium and phosphate) was obtained through a laboratory analysis. Litter productivity of R. mucronata and A. alba stands reached 4.68 and 7.11 g m−2 day−1 respectively with the biggest contributed from leaves litter. Observed different rates of mangrove decomposition was due to the lignin content. The decomposition rate of R. mucronata and A. alba were Y=12.841e−0.382X (R2=0.97) and Y=11.958e−0.478X (R2=0.91) respectively. The productivity and decomposition rate of A. alba litter was greater and faster than R. mucronata. Increased nitrates was indicated of nitrification process, while phosphate and ammonium showed decreased concentration during experiments. Aside from that, water nutrient concentration was affected by dissolved oxygen availability.

What Role Does Elevational Variation Play in Determining the Stock and Composition of Litter?

Abstract This study analyzed the role of Caatinga vegetation structure in the accumulation, composition and distribution of litter along an elevation gradient in the Brazilian semi-arid region. Fifty sampling units were established for shrub-tree vegetation analysis, and 50 1-m2 plots for sampling litter. Sampled litter was screened in fractions of leaves, stems, reproductive structures, miscellaneous and animal remains and then weighed. Total accumulated litter weighed 72.3 kg and was composed mainly of stems (45.2%). A positive correlation was found between total litter and elevation, as well as between leaf fraction and richness and basal area, while the stem fraction was negatively associated with richness, abundance and basal area. The results reflect a joint effect of abiotic factors and community structure, which produces heterogeneous environments that favor variation in litter production and quality along the elevation gradient.

Litterfall Dynamics and Nutrient Cycling in an Experimental Plantation of Peach Palm (Bactris gasipaes Kunth)

Abstract This study aimed to evaluate litterfall and nutrient dynamics in an experimental plantation of peach palm (Bactris gasipaes Kunth) in Taubate, Sao Paulo, Brazil. Litterfall was collected monthly between March 2010 and May 2011, and the plant material was separated into leaflets and rachises. During the 15-month study period, the plantation produced 9.2 Mg ha−1 of litter (4.8 Mg ha−1 of leaflets and 4.4 Mg ha−1 of rachises). Seasonal variations were observed in litter production and nutrient concentration. Litter deposition was the highest at the end of the dry season and at the beginning of the rainy season, that is, in months with low rainfall and lower minimum temperatures. Macronutrient return to the soil was estimated at 141.5 kg N ha−1, 24.8 kg P ha−1, 78.2 kg K ha−1, 55.1 kg Ca ha−1, and 37.8 kg Mg ha−1.

Characterizing plant biomass and soil parameters under exotic trees within rainforest environment in southern Nigeria

This research characterized biomass and soil parameters under exotic species of Terminalia cattapa, Mangifera indica and Persea gratissima in Southern Nigerian rainforest environment. The study area was stratified into 5 zones. In each zone, control plot measuring 30 m × 30 m and divided into 3 quadrants of 10 m × 30 m, was established from mature adjoining rainforest above 100 years, while 3 stands of each exotic species were selected. Collection of plant biomass parameters and soil samples was from 15 stands of each exotic species and control plots. Litterfall was collected daily from February 2019 to January 2020 using litter traps, heights and diameters of trees were determined using appropriate methods, while samples of soil were taken from the 0–15 cm and 15–30 cm depth using core sampler. Soil properties were analyzed by adopting standard laboratory techniques. Data analysis involved the descriptive, correlation and one-way analysis of variance (ANOVA) statistics using the SPSS 15.0 version software. Findings revealed that plant biomass and soil parameters varied significantly at 5% level of significance among the exotic and rainforest trees. Litter productions varied seasonally. Plant biomass characteristics correlated positively with soil properties. Litter production correlated with water holding capacity, total porosity, organic matter, nitrogen, phosphorus and potassium at 0.559, 0.652, 0.818, 0.805, 0.902 and 0.743 respectively for topsoil and 0.549, 0.631, 0.807, 0.801, 0.900 and 0.732 respectively for subsoil. Since the biomass parameters of the exotic trees correlated positively with soil properties, they are therefore recommended as farm trees to encourage agro-forestry practices within the rainforest environment. These agro-forestry practices prevent inorganic fertilizers' usage which is not environment friendly.

¿Es sustentable el aprovechamiento de tierra de hoja en bosques de encino?

Se investigó si el esquema actual con el que se realiza el aprovechamiento de tierra de hoja es sustentable. Con este fin se evaluó la producción de hojarasca en un bosque de encino con aprovechamiento de tierra de hoja bajo tres condiciones: sin aprovechamiento (C1), aprovechamiento en los últimos dos años (C2) y aprovechamiento de más de dos años (C3). Se estimó la cantidad anual de nutrientes (N, P, K, Ca, Mg y S) que regresa al piso forestal mediante la caída de hojarasca. Se emplearon trampas de hojarasca de 0.5 m2 de área. La producción de hojarasca fue mayor en C2 y C3 [(9.36 ± 0.64; 10.04 ± 1.92) Mg ha-1 año-1, respectivamente], en comparación con C1 [(6.74 ± 0.45) Mg ha-1 año-1]. La cantidad de nutrientes que regresa al piso forestal es 40% mayor en los sitios bajo aprovechamiento que en los sitios sin aprovechamiento. Los resultados sugieren que el aprovechamiento de tierra de hoja estimula la producción de hojarasca. Sin embargo, aun cuando pueda haber un proceso de estimulación en la producción, se debe tener cuidado con el tiempo que se deja descansar un área bajo aprovechamiento, ya que, de acuerdo con los resultados de este estudio, se requieren 14 años de descanso para aprovechar en forma sustentable un mismo sitio; es decir, un tiempo al menos dos veces y media mayor al que se da actualmente. Un esquema sustentable implica que el tiempo entre dos fechas de aprovechamiento es igual al tiempo requerido para formar la capa orgánica retirada.

Temporal and stoichiometric patterns of algal stimulation of litter‐associated heterotrophic microbial activity

Abstract Periphyton communities associated with submerged plant detritus contain interacting autotrophic and heterotrophic microbes, and are sites of extracellular enzymatic activity. The strength and nature of these interactions might be expected to change over time as microbial communities develop on plant litter. Microbial interactions and enzymatic activity can be altered by nutrient availability, suggesting that litter stoichiometry could also affect these phenomena. We grew wetland plants under ambient and nutrient‐enriched conditions to generate plant litter of differing nutrient content. In two experiments, we investigated: (1) the influence of algal photosynthesis on fungal and bacterial production and the activities of four extracellular enzymes throughout a 54‐day period of microbial colonisation and growth; and (2) the influence of litter stoichiometry on these relationships. Ambient and nutrient‐enriched standing‐dead plant litter was collected and then submerged in wetland pools to allow for natural microbial colonisation and growth. Litter samples were periodically retrieved and transported to the laboratory for experiments manipulating photosynthesis using the photosystem II inhibitor DCMU (which effectively prevents algal photosynthetic activity). Algal (14C‐bicarbonate), bacterial (3H‐leucine), and fungal (14C‐acetate) production, and β‐glucosidase, β‐xylosidase, leucine aminopeptidase, and phosphatase activities (MUF‐ or AMC‐labelled fluorogenic substrates) were measured under conditions of active and inhibited algal photosynthesis. Photosynthesis stimulated overall fungal and bacterial production in both experiments, although the strength of stimulation varied amongst sampling dates. Phosphatase activity was stimulated by photosynthesis during the first, but not the second, experiment. No other enzymatic responses to short‐term photosynthesis manipulations were observed. Microbial communities on high‐nutrient litter occasionally showed increased extracellular enzyme activity, fungal growth rates, and bacterial production compared to communities on non‐enriched litter, but algal and fungal production were not affected. Litter stoichiometry had no effects on fungal, bacterial, or enzymatic responses to photosynthesis, but the mean enzyme vector analysis angle (a measure of P‐ versus N‐acquiring enzyme activity) was positively correlated to litter N:P, suggesting that elevated litter N:P led to an increase in the relative activity of P‐acquiring enzymes. These results supported the hypothesis that algal photosynthesis strongly influences heterotrophic microbial activity on macrophyte leaf litter, especially that of fungi, throughout microbial community development. However, the strength of this photosynthetic stimulation does not generally depend on small differences in litter nutrient content. Stimulation of microbial heterotrophs by algal photosynthesis could drive diurnal shifts in periphyton community and aquatic ecosystem function, as well as linking green (photoautotroph‐based) and brown (detrital‐based) food webs.

Male reproductive input, breeding tenure, and turnover in high-density brown bear (Ursus arctos yesoensis) populations on the Shiretoko Peninsula, Hokkaido, Japan

Male reproductive behavior has not been thoroughly investigated in large, non-social mammals. We studied male reproductive input using field observations and microsatellite DNA data for the brown bear (Ursus arctos yesoensis Lydekker, 1897) population in a special wildlife protection area on the Shiretoko Peninsula in Hokkaido, Japan. We identified the father of 82 offspring born between 2006 and 2018 from 54 litters produced by 20 females and revealed that they were sired by a total of 19 males. Overall, paternity was distributed relatively evenly among different males, although litter production tended to be skewed to a few bears in some years. Male breeding tenure varied among individuals, but most tenures were within the range of 1 to 6 years. Human-caused mortality, mostly occurring near human residential areas, induced male turnover, indicating that the special wildlife protection area located in the inner part of the Shiretoko Peninsula is not free from human impact. The frequency of successful reproduction was highest in 10- to 14-year-old bears, which is consistent with the period when males reach physical maturity. These results contribute to an understanding of breeding systems in large solitary mammals and to appropriate conservation and management strategies for brown bear populations.

Fate of leaf litter in restored Kandelia obovata (S. L.) mangrove forests with different ages in Jiulong River Estuary, China

Ecological processing of leaf litter plays important roles in carbon dynamics of mangrove forests. Fate of leaf litter, that is, removal by crabs, microbial decomposition, and tidal export was quantified in two restored Kandelia obovata forests with ages of 24 years and 48 years, respectively, from December 2009 to November 2010. Crab abundance was also investigated to test the role of crabs in leaf litter processing. Daily leaf litter production was 1.064 ± 0.108 g C m−2 day−1 at the 24‐year forest and was 0.689 ± 0.040 g C m−2 day−1 at the 48‐year forest. Annual mean removal of leaf litter by crabs was lower at the 24‐year forest than at the 48‐year forest (0.177 ± 0.046 g C m−2 day−1 vs. 0.220 ± 0.050 g C m−2 day−1), due to a higher crab abundance at the older forest. Microbial decomposition and change in standing stock of leaf litter on the forest floor made a negligible contribution to the annual leaf litter production. Tidal exports of leaf litter were estimated as 0.875 ± 0.090 g C m−2 day−1 and 0.458 ± 0.086 g C m−2 day−1 at the 24‐year and 48‐year forests, respectively, accounting for 82.2% and 66.5% of their daily leaf litter production. Turnover rate of leaf litter was higher at the younger forest (1.7 ± 0.4 day−1) than the older forest (1.2 ± 0.3 day−1). Removal of leaf litter by crabs was higher in warm months while tidal export of leaf litter showed a much less apparent seasonal pattern. Spatial variations of crab removal and tidal export of leaf litter with forest zones were observed within each forest, while microbial decomposition of leaf litter was comparable among the different zones. These indicated that the ecosystem functions of restored mangrove forest could not reach a level equivalent to those of a mature forest even 24 years after restoration.

Organic carbon distribution and budget of dominant woody plant community in the subalpine zone at volcanic Jeju Island, Korea

BackgroundThe Northern Hemisphere forest ecosystem is a major sink for atmospheric carbon dioxide, and the subalpine zone stores large amounts of carbon; however, their magnitude and distribution of stored carbon are still unclear.ResultsTo clarify the carbon distribution and carbon budget in the subalpine zone at volcanic Jeju Island, Korea, we report the C stock and changes therein owing to vegetation form, litter production, forest floor, and soil, and soil respiration between 2014 and 2016, for three subalpine forest ecosystems, namely, Abies koreana forest, Taxus cuspidata forest, and Juniperus chinensis var. sargentii forest. Organic carbon distribution of vegetation and NPP were bigger in the A. koreana forest than in the other two forests. However, the amount of soil organic carbon distribution was the highest in the J. chinensis var. sargentii forest.Compared to the amount of organic carbon distribution (AOCD) of aboveground vegetation (57.15 t C ha−1) on the subalpine-alpine forest in India, AOCD of vegetation in the subalpine forest in Mt. Halla was below 50%, but AOCD of soil in Mt. Halla was higher. We also compared our results of organic carbon budget in subalpine forest at volcanic island with data synthesized from subalpine forests in various countries.ConclusionsThe subalpine forest is a carbon reservoir that stores a large amount of organic carbon in the forest soils and is expected to provide a high level of ecosystem services.

Leaf litter contributes more to soil organic carbon than fine roots in two 10-year-old subtropical plantations

Although many reports assume a strong relationship between plant litter inputs and soil organic carbon (SOC) accumulation, there is limited experimental evidence in support of this relationship. The Detritus Input and Removal Transfer (DIRT) experiment was conducted in two subtropical plantations, an Acacia crassicarpa monoculture (AC) and a Eucalyptus urophylla monoculture (EU), to assess the importance of leaf litter and fine roots for SOC content over a 6-year period. The SOC content in 0–10 cm soil layer was significantly reduced by litter removal (NL) or by removal of both litter and roots (NI), but the influence of root removal (NR) was only marginal. The AC forest had a much higher annual rate of litter production and a lower decomposition rate than the EU forest, but carbon release from plant litter did not significantly differ between the two forests. These results help explain why the SOC content did not differ between the two forests. Our findings suggest that plant leaf litter is more important than roots in maintaining the balance of the SOC pool in subtropical forest plantations.

Valuation of ecosystem services in the organic carbon of the Pinus densiflora forest at Mt. Namsan, Seoul Metropolitan City

BackgroundStanding biomass, litter production, rate of litter decomposition, amount of litter on forest floor, and amount of soil organic carbon distribution were investigated from March 2016 to November 2018 in order to evaluate the ecosystem value through organic carbon distribution in the Pinus densiflora forest at Namsan, Seoul Metropolitan City.ResultsThe amount of organic carbon in the Pinus densiflora forest was 261.09 ton C ha−1 during the research period, and fixed organic carbon in plant through net photosynthesis was 3.2 ton C ha−1 year−1. The organic carbon in plant was 62.77 ton C ha−1 (24.04%), in litter on the forest floor was 3.65 ton C ha−1 (1.40%), and in soil was 194.67 ton C ha−1 (74.56%). The value of plant, litter on forest floor, and soil organic carbon distribution were each 6,277,000 won ha−1, 365,000 won ha−1, and 19,467,000 won ha−1. The value per ton of fixed organic carbon in plant through net photosynthesis was 320,000 won ha−1 year−1 and the value of ecosystem services stored in carbon in the Namsan forest ecosystem was about 26.1 million won ha−1 for 3 years.ConclusionsThe results of this study suggest that the pine forests of Namsan rapidly decompose leaves due to the high atmospheric temperature and accumulate a large amount of organic carbon in the soil to provide climate control regulatory service function.

Litter fall and standing crop litter of<i> Bambusa vulgaris</i> Schrad. ex J.C. Wendl. stands in secondary rainforest in Ile-Ife, Nigeria

The litter fall production and standing crop litter of Bambusa vulgaris Schrad. ex J.C. Wendl. stands in four 25 m x 25 m plots were evaluated in a secondary rainforest, Nigeria. This was done with a view to providing information on litter fall production, seasonal pattern and monthly variation in bamboo stands. The litter fall was collected using litter traps of 1m x 1m x 30 cm from June 2014-May 2015 and the standing crop litter was quantified at the peak of rainy and dry seasons. The collected litters were sorted into leaf and twigs, oven-dried at 70 °C to a constant weight and weighed. The annual litter production was 13.35±1.18 t ha-1 and leaf litter contributed, 73.90% while twig litter 26.10%; the standing crop litter (t ha-1) at the peak of dry season was 2.38±0.12 (total), 1.59±0.05 (leaf), 79±0.07 (twig); and rainy season, 2.01±0.24 (total), 1.17±0.15 (leaf), 0.84±0.09 (twig). The values of litter production, leaf and twig components obtained in this study were higher than the results of previous litter fall studies obtained in this secondary rainforest though the seasonal trend (variation) was the same.© 2019 International Formulae Group. All rights reserved.Keywords: Leaf, month, seasons, twig, variation

Solar radiation exposure accelerates decomposition and biotic activity in surface litter but not soil in a semiarid woodland ecosystem in Patagonia, Argentina

Photodegradation of senescent plant material has been identified as an important vector of aboveground carbon (C) loss in aridland ecosystems, but the consequences for biotic activity and soil C in the field are not well understood. We established an experiment in a semiarid woodland in Patagonia, Argentina with attenuation of solar radiation and additions of leaf litter to evaluate impacts of photodegradation on changes in labile C and biotic activity in aboveground litter and surface soils. Litter decomposition was significantly accelerated by exposure to solar radiation. Moreover, labile sugars (hexoses and pentoses), microbial enzymatic activity (β-glucosidase activity) and available carbohydrates for cellulase degradation (saccharification) all significantly increased in sunlight-exposed litter. None of these stimulatory effects were observed in the surface soils exposed to sunlight. On the contrary, soil microbial biomass and β-glucosidase activity in surface soils were significantly greater only with litter addition and attenuated sunlight. Our results suggest that photodegradation of plant litter (production of volatile compounds through photochemical mineralization) and photofacilitation (stimulation of biotic activity due to change in litter chemistry with exposure to sunlight) generate rapid turnover of C in aboveground litter. The consequences of this accelerated C turnover may be that a fraction of leaf litter decomposes and is directly released back to the atmosphere as CO2 and never enters soil organic matter pool. Taken together, these results highlight the functional importance of solar radiation in determining the C balance in semiarid ecosystems.