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Tropical Ecology 55(2): 207-220, 2014 Decomposition and changes in chemical composition of leaf litter of five dominant tree species in a West African tropical forest

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Abstract

The objective of the research was to study the rate of decomposition and changes in the chemical characteristics in the leaf litter of selected tree species using a litterbag experiment. The decomposition of leaf litter from five dominant tree species, Afzelia africana, Anogeissus leiocarpa, Ceiba pentandra, Dialium guineense, and Diospyros mespiliformis was studied in the Lama forest reserve, a tropical vertisol forest in Benin. Changes in litter mass and organic compounds, including acid-hydrolysable (AH), water-soluble (WS) and ethanolsoluble (ES) compounds and Klason lignin, were determined every 4 weeks over 6-months period. The carbon (C), nitrogen (N), organic matter (OM) and ash contents of fresh litter were also determined. The high differences in the initial litter quality across the species resulted in a large variation of the absolute decay rate (ka values), ranging from 1.69 to 4.67 year-1. The key chemical controls of leaf decomposition were the initial concentrations of AH, lignin and N. The specific decay rates (ks values) of AH, WS, ES and Klason lignin varied significantly within and across species and described leaf litter as composed of labile and recalcitrant C pools having different decay patterns. WS and ES had the highest ks values of 4.65 to 11.96 year-1 and 4.06 to 21.27 year-1, respectively, whereas AH had ks values of 1.14 to 4.74 year-1 and seemed to impose its decay pattern on the whole litter. The results supported the hypothesis that litter chemistry was the main factor controlling the decomposition process at a local scale.

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... Forest soils are large carbon pool subject to fast dynamics in the tropics due to favorable climate (temperature, precipitation) conditions for organic matter decomposition (Mäkipää et al. 2012). However, this pool is less studied in tropical Africa owing to lack of resources and technical capacities (Guendehou et al. 2014). As a result, when estimating carbon balance in forest ecosystems in Benin or elsewhere in tropical countries, the assumption that there are no changes in carbon stock in soil is usually used. ...
... When selecting litter types for soil carbon estimation, priority should be given to leaf litter from dominant tree species. The material we used in our experiment conducted in the Lama forest, in Benin, consists of leaf litter of five dominant tree species: Afzelia africana, Anogeissus leiocarpa, Ceiba pentandra, Dialium guineense, and Diospyros mespiliformis (Guendehou et al. 2014). The following activities are required to implement the experiment: -Collect senescent leaves ready to fall from the trees by hand; stick can also be used; -Collect leaves separately by species and mix leaves of the same species; -Do not collect the leaves on the forest floor as they are considered partly decomposed; -Dry the leaves at open-air followed by oven-drying at 75 ºC to constant weight; to minimize the loss of material and changes in decomposability likely to occur at high temperature one may dry samples at 40 ºC for which the constant weight is reached after a longer period; -Use a litterbag made of polyester net fine mesh (we used 0.33 mm); a square 20 x 20 cm bag; -Place in the bags, between 20 and 30 g of oven-dried leaves. ...
... The following activities are required to implement the experiment: -Collect senescent leaves ready to fall from the trees by hand; stick can also be used; -Collect leaves separately by species and mix leaves of the same species; -Do not collect the leaves on the forest floor as they are considered partly decomposed; -Dry the leaves at open-air followed by oven-drying at 75 ºC to constant weight; to minimize the loss of material and changes in decomposability likely to occur at high temperature one may dry samples at 40 ºC for which the constant weight is reached after a longer period; -Use a litterbag made of polyester net fine mesh (we used 0.33 mm); a square 20 x 20 cm bag; -Place in the bags, between 20 and 30 g of oven-dried leaves. Sew the bag with a polyester string (cotton must not be used since it decomposes); -Place the bags on the forest floor in 4 or more plots; the distance between plots should be large enough to minimize the spatial autocorrelation between plots (Guendehou et al. 2014) (Figure 1); -Collect litterbags every 4 weeks (Figure 2) from each replicate (each plot), collect the first row at 4 weeks, the second row at 8 weeks and so on. Our experiment lasted 24 weeks; -Brush out carefully and clear of foreign material (soil, roots, fauna) the outside of the collected bags; -Open up the bags carefully to retrieve the remaining litter material; -Clean the litter carefully of all possible ingrown material (roots or shoots of plants, soil animals); -Dry the cleaned litter immediately after collection in order to stop decomposition process (dry first in open-air if oven is not available close enough to the study site); -Dry then the remaining litter in oven at 75 ºC to constant weight; -Weigh the remaining litter to determine the mass loss, which is reported either as the proportion of mass lost relative to the initial mass: í µí±€í µí±Ží µí± í µí± !"## (%) = 100 * (í µí±€ ! ...
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... Water relations (Anderson et al., 2001), availability of light (Thomsen et al., 2005), litter inputs (Sayer, 2006) and soil properties (Reich et al., 2005) may be altered by trees; even individual trees can control surrounding vegetation and soil chemistry (Brooker et al., 2008). In forest ecosystems, tree species have great impacts on physical, chemical and biological properties of soil (Guendehou et al., 2014;Gartzia-Bengoetxea et al., 2016) through their physical structure, especially their litter inputs (Schwarz et al., 2015). Litter quality characters, as the main driving force for soil processes, especially relative proportions of carbon (C) and nitrogen (N) contents vary between different tree species (Guendehou et al., 2014). ...
... In forest ecosystems, tree species have great impacts on physical, chemical and biological properties of soil (Guendehou et al., 2014;Gartzia-Bengoetxea et al., 2016) through their physical structure, especially their litter inputs (Schwarz et al., 2015). Litter quality characters, as the main driving force for soil processes, especially relative proportions of carbon (C) and nitrogen (N) contents vary between different tree species (Guendehou et al., 2014). Neirynck et al. (2000) found that C/N ratio in topsoil was variable under different tree species (i.e. ...
Article
The role of tree species on litter quality and soil characters is less known in mixed forest stand. For this reason, the effect of Carpinus betulus (CB), Acer velutinum (AV), Pterocarya fraxinifolia (PF), Quercus castaneifolia (QC) species on litter and topsoil physical, chemical and biological features was considered in northern Iran. Litter quality differs among species, with the highest total nitrogen (N) concentration (1.88%) and lowest organic carbon (C) (41.18%) under CB trees. Clay and water content did not differ among species, but soil bulk density and sand content were highest under CB (1.66 g cm− 3 and 44.70%, respectively) with the least silt content (28%). Soil pH (7.10), EC (0.29 ds/m), total N (0.35%), available P (21.85 mg kg− 1), K (316.66 mg kg− 1), Ca (254.50 mg kg− 1), Mg (58.50 mg kg− 1), earthworm density/biomass (2.50 n m− 2 and 29.59 mg m− 2, respectively) with more share of epigeic, total nematode (443.90 in 100 g soil) and microbial respiration (0.47 mg CO2-C gsoil− 1 day− 1) were significantly higher beneath CB trees whereas a higher content of organic C (3.15%) and C/N ratio (34.20) were found under QC. A greater quantity of fine root biomass was found under PF (92.80 g m− 2) trees. In all the studied tree species, earthworms (epigeic, anecic and endogeic) and nematodes had the highest activities in autumn while the maximum of microbial respiration was recorded in summer season. The findings obtained in this study can be prioritized in the selection of appropriate species for the restoration of degraded areas.
... In the case of materials from pruning, the total extractives content ranged from 10.3% (orange branches) to 35% (lime leaves). Relatively high contents of extractives have been observed in branches and leaves of different tree species (Räisänen and Athanassiadis 2013;Guendehou et al. 2014;Cárdenas-Gutiérrez et al. 2018). ...
... In the case of branches, the results obtained here are within the range found in branches of different tree species (0.08% in Quercus rugosa, 1.3% in Q. candicans) (Cárdenas-Gutiérrez et al. 2018). Inorganic substances are concentrated in the foliage of trees, compared with wood or bark, and the results obtained here agree with data reported for leaves of different tree species (Guendehou et al. 2014). ...
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The chemical composition of hardwoods sawdust and citrus residues from four states of the Mexican Republic (Quintana Roo, Durango, Veracruz, and Sonora) were determined. The results ranged as follows: total extractives from 8.2% (Quercus spp.) to 35.0% (lime leaves), holocellulose from 45.4% (lime leaves) to 70.6% (Lysiloma latisiliquum), lignin from 3.9% (lemon peels) at 25.4% (Caesalpinia platyloba), ash from 0.4% (orange branches) to 6.3% (lemon peels), pH from 5.1 (Swartzia cubensis) to 7.3 (orange branches), and calorific value of 19.8 MJ/kg (Lysiloma latisiliquum and Quercus spp.) to 21.7 MJ/kg (Olneya tesota). With the exception of the oak samples, in all the biomass samples the extractives content is relatively high (10.1% for Lysiloma latisiliquum to 35% for Persian lime leaves), and could represent a potential for future study and applications in the field of antioxidants. Due to the chemical properties and calorific value, the biomass samples studied present potential for local use as densified biofuels (pellets or briquettes).
... Leaf residues were oven dried at 70°C for a constant weight was obtained. Finally the percentage of mass remaining was calculated using following equation and then % of mass remaining was plotted at intervals of two weeks ( Guendehou et al. 2014). ...
... decomposition rates compared to that of other specie P. maximum showed the lowest decomposition rate (k= 3.41 per year) than that of the other plant species (Table 4). Several studies have adopted the litterbag technique to determine the effect of litter quality on decomposition rates (Swarnalatha & Reddy 2011, Guendehou et al. 2014). Leaf litter of different plant species has diverse nutrient release patterns, which are related to leaf quality of initial nitrogen contents and C: N ratio (Swarnalatha & Reddy 2011). ...
... In the cycling of such nutrients, decomposition processes have a crucial role by releasing a complex organic compounds into the simple usable form for proper growth and development of plants (Saha et al., 2016). Litter has thus occupied the attention of ecologists as it is an important factor in ecosystem dynamics to determine ecological productivity and may be useful in predicting soil fertility (Guendehou et al., 2014). ...
... Nutrient dynamics is broadly defined as the way nutrients are taken up, retained, transferred, and cycled over time and distance, in an ecosystem (Hauer and Lamberti, 2006;Allan and Castillo, 2007). Decomposition process plays an important role in maintaining soil fertility in terms of nutrient cycling and formation of soil OM (Usman et al., 2000;Singh et al., 2007;Guendehou et al., 2014). Slow decomposition rates result in the building up of OM and nutrient stocks in soil; however, fast decomposition rates help to meet plant intake requirements (Isaac and Nair, 2005). ...
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Leaf-litter decomposition in terrestrial ecosystems has a major role in recycling the nutrients to the soil. Nutrient dynamics is the way nutrients cycle in an ecosystem. The present study was conducted for five selected tropical tree species viz. Shorea robusta, Ficus hookeri, Mallotus philippensis, Artocarpus lakoocha and Dillenia pentagyna at Hetauda, Makawanpur. This paper aims to determine the litter decomposition rate-constant and nutrient mineralization pattern of the selected species. The litter-bag method was used to assess the decomposition and nutrient dynamics for one year. Both decomposition rate-constant and weight loss were highest for M. philippensis (% weight loss = 73.49; k = 0.33) and lowest for S. robusta (% weight loss = 54.01; k = 0.18). In general, weight remaining showed a strong negative correlation with N and P concentration but a slightly negative with K. However, the remaining weight of litter showed a strong positive correlation with C : N ratio, thus indicating a good predictor of mass loss and mineralization. The study showed that there was no net release of nitrogen during the one-year study period; however, the net P release was found to be highest for S. robusta followed by D. pentagyna and the net K release was highest in F. hookeri followed by A. lakoocha.
... The overall forest floor mass in conifer stands (PP, PN and PM) was higher in all organic layers (L, F and H) than in broadleaf stands (CS). Under the coniferous species there was a huge quantity of organic materials poorly decomposed, while under broadleaved species (CS) there was the biggest transformation of forest floor and incorporation in mineral soil, because litter chemistry was a determinant factor controlling the decomposition process (Hobbie 1996;Shaw and Harte 2001;Mueller et al. 2012;Guendehou et al. 2014;Kooch et al. 2017). These observations were in accordance of decomposition litter study conducted in these stands, which recorded annual losses of 15.3, 18.3, 29.7 and 41.7% for PN, PP, PM and CS, respectively (unpublished data). ...
... Identical results were reported by other authors (Rapp 1984;Schulp et al. 2008;Fonseca and Figueiredo 2010;Bargali et al. 2015). The lowest value found beneath the CS stand could be explained by the highest decomposition rate associated with a lower C:N ratio of the forest floor layers (Thomsen et al. 2008;Trum et al. 2011;Guendehou et al. 2014;Cools et al. 2014). Secondly, this stand was clearcut after 40 years, which had important consequences at soil level, namely alteration in the quantity and quality of biomass production, modification of the spontaneous vegetation and of microbial community composition (Merzouki et al. 1989;Prescott and Grayston 2013;Bargali et al. 2015). ...
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The organic and mineral horizons of soils are of great importance in C and N storage in forest areas. However, knowledge of the effects of forest species on the stocks of these elements is still scarce, especially in Portugal. In order to contribute to this knowledge, a study was carried out in forest stands of Pinus pinaster Aiton (PP), Pinus nigra Arnold (PN), Pseudotsuga menziesii (PM) and Castanea sativa Miller (CS), installed in the 1950s in northern Portugal. Sampling areas with similar topography, lithology and climate were selected, in order to better identify hypothesized differences in C and N storage due to forest species effect. In each stand, 15 sites were selected randomly and the forest floor (organic layers) was collected in a 0.49 m² area. The layers H, L and F of the forest floor were identified and, for L and F, their components were separated in leaves, pine cones/chestnut husks and branches. At the same sites, soil samples were also collected at 0-10 and 10-20 cm depth. At these depths, undisturbed samples were also collected for bulk density determination. The concentrations of C and N were determined in forest floor and mineral components of the soil, and converted in mass per unit area. The quantity of C storage per unit area followed the sequence PN > PM > CS > PP, while for N the sequence was CS > PM > PN > PP, OM and PP keeping the same relative position in the sequence in both C and N concentrations. The PM and CS species store similar amounts of C and N, and about 90% of these elements is found in the upper 20 cm of the mineral soil. In PN and PP species, the contribution of forest floor to the storage of these elements is more expressive than in the other species, but lower than 30% in all cases.
... As this litter comes from the aboveground biomass, its decomposition results in higher OM and C contents in upper horizons and could explain the decrease observed between the soil depths. In addition, Guendehou et al. (2014) reported that decomposition of litter chemical components (e.g. acid-hydrolysable) may be affected by the formation of stable complexes in black cotton soil. ...
... This finding suggest effects of plant species on carbon input as pointed out by Sariyildiz et al. (2015) and in the Lama forest, plant communities vary with vegetation types and explains the difference in soil patterns. This results in litter amount and the decomposition of litter (Attignon et al. 2004;Djego 2006) leading to modification of soil chemical properties and by the way OM and SOC (Guendehou et al. 2014;Guo et al. 2016). ...
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The overall objective of the research was to generate soil organic carbon (SOC) reference data for the benefit of the REDD+ initiatives. In this study, SOC was derived from direct measurements of organic matter (OM) content in soil. Six hundred and seventy five soil samples were collected to 30 cm depth in black cotton soil and across three vegetation types including undisturbed forest, degraded forest and fallow in a Guinean forest zone in West Africa. The samples were analysed for bulk densities and for soil OM using loss-on-ignition method. Between 12% and 21% OM per soil mass was found at all layers, 0–10, 10–20 and 20–30 cm, suggesting that black cotton soil was organic soil. OM and C contents and SOC were higher in the upper soil layer and decreased with depth. The highest values of these soil factors were detected in undisturbed forest. The low variation of these soil factors within each vegetation type and their fairly homogeneous spatial distribution across vegetation types confirmed that soils in degraded forest and fallow reached equilibrium, considering undisturbed forest as reference. The lowest bulk density (BD) was found in the top 10 cm layer of the soil depth. There were no significant differences between the mean values of BD observed at the same horizon across vegetation types.
... Perbedaan korelasi antara kehilangan bobot serasah dan waktu dekomposisi pada masing-masing lahan bera dapat dikaitkan dengan perbedaan kualitas serasah. Pengaruh waktu dekomposisi terhadap kehilangan bobot serasah pada lima jenis pohon di Afrika Barat berada pada kisaran 84% hingga 97% (Guendehou et al. 2014). Pada sistem agroforestri yang berumur 5 dan 10 tahun memiliki korelasi antara waktu dekomposisi terhadap kehilangan bobot serasah sebesar 0,905 hingga 0,907, lebih rendah dibandingkan regenerasi hutan alami berumur 10 tahun (0,938) (Froufe et al. 2020). ...
... Rasio C/N serasah sebelum dekomposisi pada seluruh lahan bera lebih rendah dibandingkan penelitian di daerah tropis Afrika dan Amerika Selatan (Aerts 1997;Asigbaase et al. 2020), juga lebih rendah dibandingkan serasah daun pada hutan Macaranga spp di Kalimantan (Fujii et al. 2020). Di sisi lain, rasio C/N sebelum dekomposisi pada seluruh lahan bera lebih tinggi dibandingkan pada serasah daun yang berasal dari sistem agroforestri dan regenerasi hutan alami di Brasil (Froufe et al. 2020), dan hampir dua kali lebih tinggi dibandingkan serasah daun pohon dominan di hutan tropis Afrika Barat (Guendehou et al. 2014). ...
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Karakteristik umur lahan bera memiliki peran penting dalam pengembalian hara melalui proses dekomposisi. Penelitian dekomposisi serasah dan cadangan karbon pada beberapa umur lahan bera telah dilakukan di Manokwari, Provinsi Papua Barat dari Juli 2020 sampai Januari 2021. Penelitian bertujuan menganalisis proses dekomposisi in situ serasah daun vegetasi lokal pada beberapa umur lahan bera, serta mengukur cadangan karbon dari vegetasi masing-masing lahan bera. Setiap umur lahan bera dipasang sebanyak 18 kantung serasah yang masing-masingnya berisi 20 g serasah daun dari vegetasi lokal lahan bera. Sebanyak tiga kantung serasah diambil setiap bulan dari masing-masing umur lahan bera, kemudian dikeringkan hingga bobot kering konstan. Cadangan karbon biomassa vegetasi dianalisis menggunakan persamaan alometrik berdasarkan diameter pohon setinggi dada (dbh). Hasil penelitian menunjukkan bahwa kehilangan bobot serasah setelah 6 bulan dekomposisi pada lahan bera 5, 10, dan 15 tahun masing-masing mencapai 92,62%; 94,00%; dan 97,12%. Konstanta dekomposisi (tetapan kehilangan bobot serasah) pada lahan bera 5 dan 10 tahun tergolong rendah yakni 0,65 dan 0,94. Lahan bera 15 tahun memiliki konstanta dekomposisi yang tergolong sedang yakni 1,18. Cadangan karbon pada lahan bera 5, 10, dan 15 tahun masing-masing sebesar 7,57; 32,63; dan 141,33 ton/ha. Penurunan rasio C/N setelah 6 bulan dekomposisi pada lahan bera 5, 10, dan 15 tahun masing-masing sebesar 66,67%; 56,25%; dan 39,39%. Dekomposisi serasah pada lahan bera 5 tahun dipengaruhi oleh curah hujan, sedangkan pada lahan bera 15 tahun dipengaruhi oleh kelembapan tanah. Penelitian ini mengindikasikan bahwa umur lahan bera menyebabkan perbedaan komposisi vegetasi, sehingga berpengaruh pada proses dekomposisi dan banyaknya cadangan karbon.
... The physiological processes of long-enduring trees in forest ecosystems depend on the support of their root systems, which also induce the soil physical, chemical, and biological activities and thus soil formation (Estrada-Medina et al., 2013;Guendehou et al., 2014;Gartzia-Bengoetxea et al., 2016;Meier et al., 2016;Shuangmiao et al., 2016;Kooch et al., 2017). Broad-leaved and coniferous forest trees are especially widespread in the Göksu catchment, which is a productive highland-wetland topographic basin sequence for agriculture in the south of Turkey (Demirel et al., 2010;Özdoğan, 2011). ...
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Plant species exert differential effects on soil mineralogical and micromorphological characteristics. The effect of red pine and oak tree roots on the mineralogical and micromorphological characteristics of rhizosphere soils in two sampling sites in the Göksu catchment was studied. The climate, topography, and bedrock conditions were kept consistent, whereas the plant factor was kept as the only variable in each site. Rhizosphere soils under the canopies of 100 years old and naturally occurring trees were compared via macromorphology, submicroscopy, mineralogy, and physical and chemical properties. The soils of red pine (RP1 and RP2 profiles) were determined to have higher porosity when compared to the soils of the oak tree profiles (Ok1, Ok2). However, the higher amounts of welded/cemented aggregates in the Ok1 and Ok2 profiles were probable indicators of maturity and probable stability of the aggregates/MSUs. The dominant clay mineral in sampling site 1 was kaolinite, whereas it was smectite in sampling site 2.
... Litter inputs control soil C stocks and different types of litter vary in their biodegradability, leading to differences in soil dissolved organic C (Don and Kalbitz, 2005). Increased initial litter N and decreased C:N ratio promote litter decomposition in soil (Guendehou et al., 2014). We did not measure litter N or C:N ratio but the C:N ratio of litter is slightly higher than that of green leaves due to the nutrient resorption that occurs when leaves are in their senescence phase (McGroddy et al., 2004). ...
Article
Intercropping in agroforestry systems improves ecosystem services. Appropriate species compositions and spacing regimes are critical to achieve ecosystem benefits and improve yields of all the component crops. Cocoa (Theobroma cacao) is an important cash crop globally but it requires shade for survival and growth. However, the effects of shade-tree species composition and spacing regime on nutrient cycling in cocoa plantations are not well understood. This study investigated the effects of shade tree species and spacing regimes on soil and plant nutrient availability at 8 years after plantation establishment in Papua New Guinea. Three cocoa intercropping systems were established in which T. cacao was planted with either a non-legume timber tree, Canarium indicum, or a legume non-timber tree, Gliricidia sepium. The shade-tree spacing regimes included either 8 m × 16 m or 8 m × 8 m in the Theobroma + Canarium plantations. There was an ongoing thinning regime in the Theobroma + Gliricidia plantation, with a final shade-tree spacing of 12 m × 12 m. Soil total carbon (TC) and total nitrogen (TN) were significantly higher in the Theobroma + Gliricidia plantation with 12 m × 12 m spacing and the Theobroma + Canarium plantation with 8 m × 16 m spacing than in the Theobroma + Canarium plantation with 8 m × 8 m spacing. Foliar TN and P were correlated with soil TN and P, respectively, whereas no correlation was detected between soil and leaf K concentrations. Foliar TN, P and K were under ideal concentrations for T. cacao in all of the plantations. The Theobroma + Gliricidia plantation had higher soil water extractable phosphorus (P) than the two Theobroma + Canarium plantations, probably due to frequent pruning of the G. sepium trees. Foliar C isotope composition (δ13C) of T. cacao suggested that T. cacao close to G. sepium or close to C. indicum with spacing of 8 m × 16 m and 8 m × 8 m had similar light interception. However, increased C. indicum spacing increased the light interception of T. cacao trees that were not planted next to C. indicum. This study indicated that non-legume timber trees with an optimized spacing regime can be used as overstorey shade trees for T. cacao. However, our study indicated all three plantations required fertilisation and better nutrient management.
... In general, litterfall fractions have been used to evaluate site productivity, decomposition rate and to estimate nutrient return to the soil (Cuevas & Lugo 1998;Guendehou et al. 2014;Hansen et al. 2009;Odiwe & Muoghalu 2003). However, investigating non-foliar fractions can provide additional information and provide a more comprehensive analysis of litter production. ...
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Effectiveness of litterfall in restoration of Das Velhas River riparian forest in Brazil and the use of non-foliar fractions of litter as an indicator of recovery of ecological functions were evaluated from November 2011 to October 2012. One litterfall collector of 0.25 m2 was placed in the center of each of the 15 noncontiguous 100 m2 plots to sample litterfall monthly. Litter was sorted into leaves and non-foliar fractions, branches, reproductive organs and others; oven dried and weighed in precision scales. We calculated total annual litter production by fractions. Annual litterfall was high (8.4 Mg ha-1 yr-1) and similar to that of primary and secondary riparian forests in studies conducted elsewhere. Non-foliar fractions represented 35.7% of the litterfall and showed that not all planted species are reproducing yet. The results indicated that both avifauna and insects are contributing to functional diversity. The largest input of litterfall occurred in July and August, which are the driest months. Thus, litter production has been influenced by hydric seasonality, and also by edge effects, once the forest is narrow (< 50 m) and can be considered itself as an “edge”. Litterfall was a useful indicator, showing that forest was productive and the litter fall was contributing to the nutrient cycle. Non-foliar fractions indicated the recovery of ecological functions in the forest, suggesting that litterfall can be used as indicator of restoration of ecological services.
... Litter inputs control soil C stocks and different types of litter vary in their biodegradability, leading to differences in soil dissolved organic C (Don and Kalbitz, 2005). Increased initial litter N and decreased C:N ratio promote litter decomposition in soil (Guendehou et al., 2014). We did not measure litter N or C:N ratio but the C:N ratio of litter is slightly higher than that of green leaves due to the nutrient resorption that occurs when leaves are in their senescence phase (McGroddy et al., 2004). ...
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The selection of shade trees with appropriate spacing is important for minimising their impact on nutrient accumulation by understorey cash crops in agroforestry systems. Cocoa trees may be intercropped with overstorey legume or non-legume shade trees. A legume tree and/or a non-legume timber tree with edible kernels (Gliricidia sepium and Canarium indicum, respectively) are used as shade trees in cocoa plantations particularly in Papua New Guinea. This study explored the nutrient concentrations of cocoa beans in response to both tree-shade species and shade-tree spacing regime. The study also investigated the extent to which C. indicum tree spacing altered the nutrient concentrations of canarium kernels. G. sepium trees in the study had a final spacing of 12 m × 12 m while the spacing regimes of either 8 m × 8 m or 8 m × 16 m used for C. indicum. The calcium (Ca) concentrations of cocoa beans did not differ significantly between plants located next to G. sepium and plants located next to C. indicum. Cocoa beans next to C. indicum trees with spacing of 8 m × 16 m had higher potassium (K) concentrations than those next to G. sepium trees. However, phosphorus (P) concentrations of cocoa beans next to C. indicum trees with spacing of 8 m × 8 m or next to G. sepium trees were significantly higher than those next to C. indicum trees with spacing of 8 m × 16 m. The K concentrations in cocoa beans and soil were not correlated nor were the P concentrations in cocoa beans and soil. Correlations between nutrients in leaves and cocoa beans, or between leaves and canarium kernels, were not strong. Our results suggest that cocoa and canarium trees can be intercropped successfully, and that they do not compete for soil nutrients.
... Litterfall plays an important role in nutrient cycling, availability and soil organic matter content in forest ecosystems through litterfall decomposition processes (Schulze 2000;Bansal et al. 2014;Guendehou et al. 2014;Tutua et al. 2014). The litterfall decomposition is a function of litterfall quality which is mostly determined by the values of carbon (C), nitrogen (N) and C/N ratio in litterfall (Bragazza et al. 2012;Whittinghill et al. 2012). ...
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Purpose: The main objective of this study was to examine the potential of using hyperspectral image analysis for prediction of total carbon (TC), total nitrogen (TN) and their isotope composition (δ13C and δ15N) in forest leaf litterfall samples. Materials and methods: Hyperspectral images were captured from ground litterfall samples of a natural forest in the spectral range of 400–1700 nm. A partial least-square regression model (PLSR) was used to correlate the relative reflectance spectra with TC, TN, δ13C and δ15N in the litterfall samples. The most important wavelengths were selected using β coefficient, and the final models were developed using the most important wavelengths. The models were, then, tested using an external validation set. Results and discussion: The results showed that the data of TC and δ13C could not be fitted to the PLSR model, possibly due to small variations observed in the TC and δ13C data. The model, however, was fitted well to TN and δ15N. The cross-validation R2 cv of the models for TN and δ15N were 0.74 and 0.67 with the RMSEcv of 0.53% and 1.07‰, respectively. The external validation R2 ex of the prediction was 0.64 and 0.67, and the RMSEex was 0.53% and 1.19 ‰, for TN and δ15N, respectively. The ratio of performance to deviation (RPD) of the predictions was 1.48 and 1.53, respectively, for TN and δ15N, showing that the models were reliable for the prediction of TN and δ15N in new forest leaf litterfall samples. Conclusions: The PLSR model was not successful in predicting TC and δ13C in forest leaf litterfall samples using hyperspectral data. The predictions of TN and δ15N values in the external litterfall samples were reliable, and PLSR can be used for future prediction.
... Consequently, the amount of 137 Cs in the exchangeable fraction increased for the decomposed-litter-mixture samples. Some previous studies also observed changes in chemical composition of soil 13 and litter 14,15 by digestion. Additionally, Coeurdassier et al. 16 showed an increase of the water-soluble cadmium fraction in soil with earthworms. ...
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The effects of the Japanese horned beetle larvae on the transfer of 137Cs from a contaminated leaf litter to the leaf vegetable, komatsuna (Brassica rapa var. perviridis) was studied. Feces of the larvae which were fed 137Cs-contaminated leaf litter were added to a potting mix in which komatsuna plants were cultivated. The presence of feces increased the harvest yield of komatsuna, suggesting that feces provided nutrients for the plant growth. In addition, the amount of exchangeable 137Cs in leaf litter was experimentally confirmed to be enhanced by the presence of feces which were excreted by larvae feeding. However, there was no difference in the soil-to-plant transfer factor of 137Cs for the presence and absence of feces. Interactions between clay minerals and exchangeable 137Cs in the soil beneath the litter layer may diminish the root uptake of 137Cs. From these results, it was concluded that the effect of exchangeable 137Cs released from feces was limited for the transfer of 137Cs to plants if plant roots were not present in litter layers.
... Five litterbags were collected every 30 days from each site (one bag from each placement location in the field), brought to the laboratory, carefully brushed out and cleared of foreign material (soil, roots and fauna), and the remaining litter in the bag was dried in open air and then oven-dried at 80°C to constant weight before being weighed to determine the mass loss [26]. ...
Article
Decomposition dynamics and N and P release from Perilla frutescence were assessed for suitability of its leaves to reincorporate into cropping systems for nutrient enrichment in the Indian Himalayan Region. Nitrogen concentration was greater in the green leaves of Perilla sp. and phosphorous in the freshly fallen leaf litter. Lignin concentration varied between 11.95 and 26.94% and registered an increase trend across altitudinal gradient. Decay pattern of Perilla leaf litter was similar at three different altitudes studied, an initial lag phase of 30 days, followed by an exponential rate of weight loss. Overall, the decay constant (k) was lower in the higher altitude (1082 m asl), as studied, and the altitudinal trend is synchronous with initial lignin concentration in the Perilla leaf litter. The study also indicated that the role of Perilla leaves in P recycling is greater than the recycling of N, therefore, reincorporation of Perilla residues could help in P enrichment through solubilization of P by microbial decomposition.
... A major determinant that predicts microbial colonization and subsequently leaf decomposition rates is the quality of leaf litter (Bakker et al. 2011;Boyero et al. 2016;Chapin et al. 2011;Guendehou et al. 2014;Loranger et al. 2002). High quality litter with higher abundance of labile substances decomposes faster than low quality litter with high concentrations of recalcitrant compounds (Chapin et al. 2011;Fonte and Schowalter 2004). ...
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Rapid and extensive conversion of tropical forests into oil palm (Elaeis guineensis) (OP) plantations pose serious threats to tropical stream processes. To mitigate land use change impacts on stream ecosystems, retention of riparian vegetation is typically proposed. We evaluated the effectiveness of a gradient of riparian qualities in oil palm streams: (1) natural forest; (2) OP-native forested buffer; (3) OP-native understory, no chemical input (OPOP) and (4) OP-no buffer, to mitigate impacts on in-stream litter processing. Leaf bag method entry using two leaf species of contrasting litter quality (Macaranga tanarius and OP) were deployed into streams. Across all riparian types, microbes were the main drivers of decomposition with negligible macroinvertebrate shredding activities. Leaf decomposition rates were more influenced by litter quality than changes in environmental conditions in the different riparian types. Across all sites, native Macaranga litter decomposed approximately 5× faster than OP litter possibly due to high structural compounds in OP leaves. Macaranga litter was also more susceptible to changes in environmental conditions as leaf decomposition positively correlated to phosphorus and potassium content. However, OP leaves were resilient to stream environmental changes and decomposed slower only at OPOP sites. These varying responses reveal complex interactions within tropical stream ecosystems. We suggest that riparian management strategies as well as plans to restore functioning in degraded tropical streams should ensure a wide diversity of native riparian tree species in order to effectively mitigate adverse OP plantation impacts on tropical stream functioning.
... The litterfall do not always reflect the litter layer in the forest floor (Table 3 and Figure 2), notably in the E1 area, where greatest amount of litterfall in the first year, did not result in highest litter layer in the same year. The dynamics of the litter layer depends not only on the litterfall amount, but also on the combination of factors such as, decomposition rate, nutrient availability and forest age, that are decisive in the biogeochemical cycles and ecosystem structure (Guendehou et al., 2014;Pinto et al., 2016;Schumacher et al., 2013). ...
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The aim of this study was to evaluate the litter dynamics in the seasons of the year in three areas: Forest formation Cerradão (CE), and in two hybrids stands of Eucalyptus urophylla × E. grandis with different ages: E1 (34-58 months) and E2 (58-82 months). The produced litter, stored litter and the remaining mass was collected over 720 days. The evaluation of the remaining litter mass in each area was performed from the random distribution of 648 litter bags on the soil. Chemical analyzes (N, P, C) and the structural components of the cell wall (lignin, cellulose and hemicellulose) of the remaining litter were performed. The C of the litter stock was also determined. For both years of evaluation were observed higher biomass and C content in litter at E2. In contrast, the highest decomposition rate was for the CE, especially in the second year of evaluation (mass remaining at 720 days of 35%, 37% and 23% for E1, E2 and CE, respectively), attributed to the higher apparent liberation of N, soil moisture and biodiversity in the native area. Lignin contents increased, cellulose decreased, and hemicellulose remained stable throughout the 720 days. It was also observed an increase in the N and P concentration of the remaining mass and positive correlations among the remaining mass and the C:N and C:P ratios. The C:N ratio of litter was ≥ 76:1 at time 0 and ≥ 30:1 at 720 days for the three areas.
... 4). Our results are in accordance with the conclusions that differences in litter decomposition are related to leaf litter quality and varying C/N ratios, C/P ratios and C content (e.g., see [14,32,33]). As addressed by Reich et al. [34] and Hobbie et al. [35], litter calcium concentrations among tree species had a profound effect on soil pH and native earthworm abundance and diversity, and were also key factors in determining species effects on forest floor leaf litter dynamics. ...
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As an important non-wood forest product and wood substitute, Moso bamboo grows extremely rapidly and hence acquires large quantities of nutrients from the soil. With regard to litter decomposition, N and P release in Moso bamboo forests is undoubtedly important; however, to date, no comprehensive analysis has been conducted. Here, we chose two dominant species (i.e., Cunninghamia lanceolata and Phoebe bournei), in addition to Moso bamboo, which are widely distributed in subtropical southeastern China, and created five leaf litter mixtures (PE100, PE80PB20, PE80CL20, PE50PB50 and PE50CL50) to investigate species effects on leaf litter decomposition and nutrient release (N and P) via the litterbag method. Over a one-year incubation experiment, mass loss varied significantly with litter type (P < 0.05). The litter mixtures containing the higher proportions (≥80%) of Moso bamboo decomposed faster; the remaining litter compositions followed Olson’s decay mode well (R2 > 0.94, P < 0.001). N and P had different patterns of release; overall, N showed great temporal variation, while P was released from the litter continually. The mixture of Moso bamboo and Phoebe bournei (PE80PB20 and PE50PB50) showed significantly faster P release compared to the other three types, but there was no significant difference in N release. Litter decomposition and P release were related to initial litter C/N ratio, C/P ratio, and/or C content, while no significant relationship between N release and initial stoichiometric ratios was found. The Moso bamboo–Phoebe bournei (i.e., bamboo–broadleaved) mixture appeared to be the best choice for nutrient return and thus productivity and maintenance of Moso bamboo in this region.
... This process is an important driver for soil characteristics such as soil carbon content, nitrogen content, cation exchange capacity and pH in the forest topsoil layer (Augusto et al. 2015;Dawud et al. 2016;Bohara, Yadav, Dong, Cao, & Hu, 2019). Xiao, Chen, Kumar, Chen, & Guan, (2019) stated that tree species diversity affects the microenvironment conditions and litter decomposition rate as well as the chemical composition of the litter of overstory species which are an essential factor for the soil carbon and nitrogen content (Guendehou et al. 2014) and influencing the soil pH and nutrients (Eshaghi Rad, 2014;Lorenz & Thiele-Bruhn, 2019). Also, Bartels and Chen (2013) concluded that total nitrogen content, exchangeable phosphorus, and cation exchange capacity had a significant positive correlation with the composition of tree species in the overstory stratum. ...
... Knowledge of these processes is crucial for generating ideas about the factors controlling rate of decay. Decomposition process plays an important role in maintaining soil fertility in terms of nutrient cycling and the formation of soil organic matter (Singh et al., 2007;Guendehou et al., 2014). ...
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Imperata cylindrica is a dominant grass species in North East India and is traditionally managed in the family farms for socioeconomic purposes. However, little is known about its role on ecosystem dynamics and nutrient fluxes. The present study was undertaken in Barak Valley part of North East India to study the leaf, root and rhizome litter production, litter mass loss, litter chemistry and decomposition dynamics of leaf, root and rhizome litter, and pattern of nutrient release from the leaf, root and rhizome litter. The mean monthly surface and belowground litter production was recorded as 64 and 215 kg ha-1 respectively. The annual total litter production in Imperata grassland was 3344 kg ha-1. The time required for 50% and 99% decomposition of litter residue was shorter for surface litter than the belowground litter. The concentration of N, P, K and C was more in surface litter than the belowground litter. Belowground litter returned more nutrients to soil system than surface system. Imperata cylindrica with slow decomposition of its belowground litter can help in soil organic matter build up in the long run, and therefore prove efficient in soil health conservation.
... Plant litter acts as the temporary sink for nutrients and slow release of nutrients guarantees the permanent contribution to the soil. Litter decomposition plays a major role in maintaining soil fertility in terms of nutrient cycling and formation of the soil organic matter (Singh et al., 2007;Guendehou et al., 2014;Bargali et al., 2015). Litter dynamics studies are crucial in the nutrition budgeting in tropical ecosystems where vegetation depends on the recycling of the nutrients held in the plant debris (Prichett and Fisher, 1987). ...
Article
Thyrsostachys oliveri is a bamboo species native to Myanmar cultivated in Arunachal Pradesh, Uttar Pradesh, Kerala and Tamil Nadu, India. Due to multifarious uses, this species has been preferred by farmers for large-scale cultivation all over India. Little is known about litter production, decomposition and nutrient release dynamics of this species. Litter dynamic studies are imperative, prior to integration of a species into any plantation program or agroforestry systems. The present study is framed to investigate the litter production, decomposition and nutrient release dynamics of T. oliveri. Litter production during 2010-2011 was quantified using specially designed litter traps made of bamboo baskets with a diameter of 1 m and depth 10 cm. Litter decomposition was studied using nylon litter bag techniques. The total annual litter production of this species was to the tune of 4.488 t ha-1. The major share of total litterfall in T. oliveri was contributed by leaves (93.60±0.99 %) followed by branches (5.82±0.99 %) and culm sheaths (0.76±0.75 %). Litter production followed a biphasic pattern with a major peak in February 2011 and minor peak in July 2010. Weight loss expressed as percentage of the original dry weight decreased exponentially with time and the mass loss in T. oliveri was a good fit to exponential decay model. The decomposition rate constant of T. oliveri was 0.009 day-1 and the half-life was 77 days. The release of nutrients from the decomposing litter was in the order Mg > N > Ca > P > K.
... After death, the plant detritus sustains decomposition, acting as an important energy source for aquatic heterotrophy organism, playing an essential role in the biogeochemical cycles of C, N and P. The extrinsic factors as pH and water trophic state (chemical drive functions) and temperature (physical drive function) conditioned organic matter decay (Harrison, 1989). Also intrinsic factors as detritus C:N:P stoichiometry (Scott et al., 2013) and litter quality (Guendehou et al., 2014) associated with heterotrophic enzymatic ability of microbial community affect the elements turnover. Depending on the metal concentration in aquatic environments, they can be considered an extrinsic factor that acting as micronutrient requirement to the microbial community (Overmann, 2006), and consequently, increasing the turnover rates of elements due to decomposition, or playing a toxic role on microbial metabolism that mediated degradation. ...
... [14] Decomposition processes play an important role in maintaining soil fertility in terms of nutrient cycling and the formation of soil organic matter. [15,16] Significantly higher organic carbon and soil moisture content may be due to increased input of organic matter by plant residues (litter) of dense Sal forest. [17,18] A unique balance of chemical, physical and biological components contribute to maintaining soil quality and availability of nutrients. ...
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In recent decades, the Sal-dominated tropical deciduous forests (TDFs) were experiencing loss of regeneration due to lack of seed germination of native species. To understand this ecological problem, the present study dealt with the spatial and temporal variations in biogeochemical parameters of Sal forest soils. Twenty soil samples were collected from four TDF sites in the Chota Nagpur Plateau, India. The inventories of tree species in three life-cycle stages (seedling, sapling and adult) were carried out in four sites. Site-I (290 stems ha−1) showed occurrence of only one species (Shorea robusta) without seedling and sapling. The pH of forest soils was acidic to slightly acidic in nature. Seasonal variations in C/N ratio showed rapid mineralization of organic matter in the rainy season. ANOVA revealed that the degree of seasonal variation caused significant difference in pH, soil organic carbon, soil organic matter, total carbon, Al, Fe, Ca, Mg, Mn and P across four sites. The strong correlation of P with pH, Al, Fe, Mg and Mn indicated highly oxidised and exchangeable nature of dry forest soils. Factor analysis of soil parameters revealed that the different combinations of edaphic conditions in different seasons were important in the distribution of the dry tropical forests communities in Chota Nagpur Plateau.
... While microbiologists seek to specify the fungus-specific macromolecular compounds and basic chemical elements, these characters are difficult to link to soil C cycle mechanisms. Instead of analysing individual chemical components or complex chemical compounds of fungal biomass that are possibly a proxy for decomposability 5,10,32 , we opted to characterize fungal biomass through general traits of litter decomposability known to drive soil C cycling 42,48,49 . Recently, it has been suggested that labile and recalcitrant C compounds originating from decomposing organic matter might follow distinct pathways of stabilization depending on the abundance of soil saprotrophic organisms 50,51 . ...
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The chemical quality of soil carbon (C) inputs is a major factor controlling litter decomposition and soil C dynamics. Mycorrhizal fungi constitute one of the dominant pools of soil microbial C, while their litter quality (chemical proxies of litter decomposability) is understood poorly, leading to major uncertainties in estimating soil C dynamics. We examined litter decomposability of arbuscular mycorrhizal (AM) and ectomycorrhizal (EM) fungal species using samples obtained from in vitro cultivation. We showed that the chemical composition of AM and EM fungal mycelium differs significantly: EM fungi have higher concentrations of labile (water-soluble, ethanol-soluble) and recalcitrant (non-extractable) chemical components, while AM fungi have higher concentrations of acid-hydrolysable components. Our results imply that differences in decomposability traits among mycorrhizal fungal guilds represent a critically important driver of the soil C cycle, which could be as vital as is recognized for differences among aboveground plant litter.
... The conservation of the tree component in grazing areas allows transforming traditional livestock systems into more sustainable productive systems [3]. In addition, it is important to know the effect of scattered trees in pastures on soil properties [16,17], ecosystem services [18] and animal production [19,20]. The presence of trees in pastures have several agroecological advantages [21]. ...
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Trees dispersed in grazing areas are contribute to the sustainability of livestock systems. The interactions between trees and soil are ecological processes that allow the modification of the biology, fertility, and physics of the soil. This study was aimed to assess the influence of dispersed trees in pastures on soil properties in grazing areas for dual-purpose cattle systems in the Piedmont region of the Colombian Amazon. The work was done in grazing areas with scattered trees at the Centro de Investigaciones Amazónicas CIMAZ–Macagual in Florencia—Caquetá—Colombia. We evaluated the effect of five tree species, Andira inermis , Bellucia pentámera , Guarea Guidonia , Psidium guajava and Zygia longifolia , on soil properties (up to 30 cm soil depth) under and outside the influence of the crown. Under the tree crown, three points were systematically taken in different cardinal positions. This was done at a distance corresponding to half the radius of the tree crown. The sampling points in the open pasture area (out of crown) were made in the same way, but at 15 m from the crown border. The ANOVA showed significant interaction (P < 0.0001) between tree species and location for macrofauna abundance up to 30 cm soil depth. For this reason, we performed the comparison between locations for each tree species. Chemical soil variables up to 10 cm soil depth only showed interaction of tree species-location for exchangeable potassium (P = 0.0004). Soil physical soil characteristics up to 30 cm soil depth only showed interaction of tree species-location at 20 cm soil depth (P = 0.0003). The principal component analysis for soil properties explained 61.1% of the total variability of the data with the two first axes. Using Monte Carlo test, we found crown effect for all species. Trees help to control exchangeable mineral elements that can affect the soil, potentiate basic cations such as magnesium and potassium, increase the abundance of soil macrofauna; but some trees with high ground level of shade in grazing areas could increase soil compaction due to the greater concentration of cattle in these areas.
... Singh et al. (1990) have stated that abundance of decomposing microbes depends partly on the native litter through its influence on soil properties. Decomposition process plays an important role in maintaining soil fertility in terms of nutrient cycling and the formation of soil organic matter (Bargali et al. 1993;Guendehou et al. 2014;Gupta & Singh 1977;Pandey & Singh 1982;Singh et al. 2007;Usman et al. 2000). Decomposition is regulated by soil organisms, environmental conditions and chemical nature of the litter. ...
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The present study was conducted in a tropical dry deciduous forest at Barnawapara wildlife sanctuary, Raipur, Chhattisgarh, India. Leaf litter decomposition and nutrient release were studied in four tree species viz., Shorea robusta C.F. Gaertn.f., Madhuca indica J.F. Gmel., Diospyros melanoxylon Roxb. and Schleichera oleosa (Lour.) Oken. The objectives of the study were to determine the weight loss and nutrient mineralization pattern of leaf litter of these four major species. The weight loss was fastest in S. robusta and slowest in M. indica. Monthly weight loss was positively related (P < 0.05) with the climatic factors (rainfall, temperature and relative humidity) except for M. indica for which the relationship was not significant. Weight remaining was inversely related (P < 0.01) to N and P concentrations, but was positively related to K concentration. The nutrient content in the residual litter decreased continuously with time for all species, except in the case of P for S. robusta and D. melanoxylon. We conclude that S. robusta decomposed at fasters rate followed by D. melanoxylon, S. oleosa and M. indica. The former species also released the two important nutrients (N and P) at a faster rate as compared to the other species. M. indica showed the slowest decomposition rate and nutrient release.
... The nutrient status of forest land and its impact on microbial processes have been preserved for a long time, even in the case of reduced nitrogen deposition, attributed to the mobilization of large amounts of organic nitrogen stored in the system (Dörr et al. 2010). Guendehou et al.(2014) studied the changes and decomposition of chemical components in the leaves of ve dominant tree species in tropical forests and concluded that the chemical quality of litter was the main factor in the decomposition process, including acidolysis chemicals, lignin, and initial concentration. Many studies have shown that nitrogen has a negative effect on the decomposition at the later stage of decomposition. ...
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Purpose Litter decomposition is a key process of nutrient cycling in terrestrial ecosystems, an important part of the global carbon budget, and deeply affected by global atmospheric nitrogen deposition. However, the effects of different forms of N addition on litter decomposition and nutrient release are unclear in a cold temperate coniferous forest in a subtropical Chinese plateau. Methods Three N sources (NH4)2SO4, NaNO3, and NH4NO3 were used in the gradient N deposition method. Each N source was divided into four treatments, from low to high, they were CK (control 0 kg N·hm− 2·a− 1), low N (low-N 5 kg N·hm− 2·a− 1), medium n (medium-N 15 kg N·hm− 2·a− 1), high N (high-30 kg N·hm− 2·a− 1), and each treatment repeated three times. Results After two years, the litter decomposition rates of low and medium ammonium nitrate treatments were the fastest as compared to the control, while high and low ammonium nitrate treatments were the slowest. Under the same nitrogen deposition conditions, the litter decomposition rates of low nitrogen treatments were higher than high nitrogen treatments. The order of litter decomposition rates was ammonium nitrate > ammonium sulfate > sodium nitrate. Nitrogen deposition decreased the amount of C in litter leaves but increased N and P levels slightly. Phosphorus changes over time were more complex than C and N over time. Conclusions These results showed that high nitrogen deposition in the future could increase litter decomposition rates and delay the nutrient release, which may be beneficial to improve soil carbon sequestration.
... In addition, some identical results have also been obtained in a plantation of stone pine on a clay mine reclamation site (Karatepe et al., 2020) and in a stone pine plantation on a sand dune in Tarsus-Turkey (Kizildag et al., 2012). The accumulation of the forest floor is generally confirmed under coniferous species (Bargali et al., 2015;Fonseca & Figueiredo, 2018;Kantarcı, 2000), and enormous amounts of dead organic materials slowly decompose because the decomposition process is controlled by the chemistry of the forest floor as a determining factor (Guendehou et al., 2014;Kantarcı, 2000;Kooch et al., 2017). Low activity of decomposer organisms may also have an impact on reluctant decomposition and forest floor accumulation. ...
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pine stands. However, total forest floor accumulation significantly increased with the development stage (28-60 t/ha in stone pine and 17-64 t/ha in maritime pine). In both species, the N concentrations in the forest floor layers differed significantly among the development stages, and the N concentrations tended to increase as the development stage increased in the L + F layer, whereas a fluctuating trend was observed in the H layer. Although the N content of the humus layer of stone pine did not show a significant difference among the development stages, the N content in the total forest floor was determined to be 0.1-0.5 t/ha in maritime pine and 0.2-0.5 t/ha in stone pine. The relationship between the mean stand DBH and the N stock of the total forest floor was determined to have a higher correlation in maritime pine (R2 = 0.8) than stone pine (R2 = 0.4). In conclusion, the nitrogen concentrations and nitrogen contents of the forest floor were remarkably different in stands introduced with different tree species, indicating the accumulation of forest floor nitrogen.
... For instance, leaf litter with a low C/N ratio and lignin content has been found to have higher decomposition rates in a great number of studies (Vargas et al. 2006, Wang et al. 2009, Yang & Chen 2009, Purahong et al. 2016. In general, the concentrations of C and N in leaf litter vary with the plant species (Guendehou et al. 2014). Polyphenols are compounds of highly variable solubility and are relatively resistant to decay (Kainulainen & Holopainen 2002, Ristok et al. 2017. ...
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Leaf litter decomposition plays a vital role in the nutrient budget of forest ecosystems. Fungal communities colonising leaf litter are "key players" in decomposition and nutrient recycling, because of their ability to produce a wide range of extracellular enzymes that facilitate breakdown of leaf litter. Fungal colonization of decomposing leaf litter is a sequential process during which fungal communities tend to change both quantitatively and qualitatively. Most previous studies on fungal succession have taken synecological approaches, recording fungal species assemblages at different stages of decomposition in various plant species. This paper brings together various studies on leaf litter decomposition, fungal succession of leaf litter including study methods, succession stages, controlling factors, limitations and future perspectives. We discuss high throughput methods as emerging complementary approaches to better understand species diversity and community dynamics. We propose the importance of current approaches combining morphological and molecular data in fungal succession studies. Nevertheless, there are still opportunities for further breakthroughs in this area as few research groups have applied these techniques to fungal succession experiments.
... The reason for this condition was associated with variable N immobilized. This result was in line with Guendehou et al. (2014) where the high differences in the initial litter quality (carbon and nitrogen) across the species contributed to absolute decay rates (k), ranging from 1.69-4.67 year -1 . ...
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The kinetics of N release during the process of decomposition of organic matter is influenced by organic matter quality, temperature, humidity, and decomposer. Acacia, coffee, salacca, and bamboo leaf litter are native plants and be the pioneer plants on the slopes of Mount Merapi after the eruption in 2010. However, there is a lack of information on the N mineralization process from the leaves litter of acacia, coffee, salacca, and bamboo. The study aimed to determine the kinetics of N release from the litter leaves of acacia (Acacia decurrens), coffee, salacca, and bamboo, which were tested with three approaches, namely zero order, first order, and second order. The experiment was carried out using 10 Phretima californica earthworms that were incubated with 35g of annual plant leaves at 25°C. The levels of NH4+ and NO3- were measured at 0, 7, 15, 30, 45, 75, and 105 days after incubation by using the indophenol blue and derivative spectrophotometric method, respectively. Throughout the decomposition 105 days, the release of NO3- was higher than that of NH4+ due to the nature of NH4+ that was more easily immobilized than NO3-. The highest NO3- release in acacia litter (1.56 mg kg-1) occurred 30 days after incubation, while in coffee, salacca, and bamboo occurred 105 days after incubation, reaching 1.92 mg kg-1, 2.47 mg kg-1, and 1.88 mg kg-1, respectively. High N compound on the leaves litter unaffected to increasing total biomass earthworms in the end of incubation however promotes N mineralization rapidly. The kinetics of the second-order equation showed higher compatibility than the other equations to the N release with coefficient determination was higher. The kinetics of mineralization can be a strategy to use the leaves litter of perennial plants as sources of N nutrient input into soil.
... Previous studies (e.g. Cleveland et al., 2006;Kaspari et al., 2008;Guendehou et al., 2014) have documented that the decomposition in temperate ecosystems is influenced by the forest floor N and P contents and the C/N ratio. Sariyildiz and Anderson (2005) described that beech forest floors contain more nitrogen at the final stage of development. ...
Article
Native to Eurasia, Eastern Europe, and Western Asia, Oriental beech (Fagus orientalis Lipsky) stands extend from the north-western part of Turkey, the eastern part of the Caucasus Mountains in Georgia and Russia to the Alborz Mountains in Iran. The effect of different development stages of beech stands on the forest floor and soil characteristics are so far almost unknown. For this purpose, the Langa forest that is located in northern Iran was investigated to detect the effect of forest development on major traits of soil biology and related soil characteristics. For this aim, 45 forest floors and soil samples (15 samples per each development stage i.e. initial, optimal, and decay stage) were analysed. In addition, the water content, temperature, and biological dynamics were monitored over the different development stages in summer and fall. Among the considered independent factors, the development stage of beech had the largest explanatory power for the variations of the soil water content (34.7%), total earthworm density and biomass (29.6% and 32.3%, respectively), Acarina (30.3%), nematode (64.3%), protozoa (57.7%), bacteria, (62.8%), fungi (59.5%), basal respiration (53.0%), substrate-induced respiration (53.8%), microbial biomass carbon (30.4%), microbial biomass nitrogen (36.0%), microbial biomass phosphorous (59.1%) and net nitrification rate (19.1%). Soil temperature (42.5%), collembola density (18.2%), net ammonification rate (29.9%), and net N mineralization rate (2.1%) were predominantly determined by the seasons. With the ageing of the forest stands, soil fertility, biota abundance, and soil function were enhanced. To figure out the most vital soil features affecting C and N sequestrations, a stepwise regression model was applied. Carbon sequestration correlated positively to N, the C/N ratio, and negatively to porosity, and the nematode abundance. In addition, nitrogen sequestration correlated positively to C, the sand content, and fine root biomass and negatively to the C/N ratio, soil porosity, and aggregate stability. Although all forest stages of the Oriental beech have an important ecological role and their place in the evolutionary process, the old-growth (i.e. decay) stage is especially important for the soil functions exhibiting the highest fertility and biological relevance. The understanding of ecological changes within different development stages can be helpful in forest management and the evaluation of silvicultural methods.
... Ce flux joue un rôle si important dans le cycle du carbone des écosystèmes forestiers que l'escamoter du bilan du carbone conduit à une sous-estimation du stock de carbone des forêts (Guendehou et Mensah, 2015). La décomposition de la litière, en fonction des conditions édapho-climatiques, conduit à une émission de carbone dans l'atmosphère et à l'incorporation du carbone restant dans le sol (Guendehou et al., 2014a(Guendehou et al., et 2014b. Comment quantifier le flux de carbone imputable à la litière de feuilles ? ...
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En forêt tropicale décidue ou semi-décidue où les arbres perdent une grande partie de leur feuillage pendant la saison sèche pour limiter les besoins en eaux, la litière de feuilles constitue un flux important de carbone de la biomasse vivante vers la matière organique morte. Ce flux joue un rôle si important dans le cycle du carbone des écosystèmes forestiers que l’escamoter du bilan du carbone conduit à une sous-estimation du stock de carbone des forêts. La décomposition de la litière, en fonction des conditions édapho-climatiques, conduit à une émission de carbone dans l’atmosphère et à l’incorporation du carbone restant dans le sol. Comment quantifier le flux de carbone imputable à la litière de feuilles ? La présente fiche technique expose les grandes lignes et les principales étapes de la quantification du flux de carbone de la biomasse vivante vers la matière organique morte.
... This process is an important driver for soil characteristics such as soil carbon content, nitrogen content, cation exchange capacity and pH in the forest topsoil layer (Augusto et al. 2015;Dawud et al. 2016;Bohara, Yadav, Dong, Cao, & Hu, 2019). Xiao, Chen, Kumar, Chen, & Guan, (2019) stated that tree species diversity affects the microenvironment conditions and litter decomposition rate as well as the chemical composition of the litter of overstory species which are an essential factor for the soil carbon and nitrogen content (Guendehou et al. 2014) and influencing the soil pH and nutrients (Eshaghi Rad, 2014;Lorenz & Thiele-Bruhn, 2019). Also, Bartels and Chen (2013) concluded that total nitrogen content, exchangeable phosphorus, and cation exchange capacity had a significant positive correlation with the composition of tree species in the overstory stratum. ...
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Revealing the effect of mixed beech and hornbeam stands on herb layer diversity is essential for sustainable forestry and biodiversity conservation since little is known in Hyrcanian forests. So, we studied the effects of such stands on understory diversity and soil physico-chemical properties in Hyrcanian forests of Iran. Forty sampled plots were established by random systematic sampling method with a regular 100 m × 200 m grid. At each sample point we recorded species identity and percent cover of each tree layer and herb layer species within plots of size 400 m2 (20 m × 20 m) and 100 m2 (10 m ×10 m) respectively. Soil samples were taken from 0 cm -10 cm and 10 cm - 30 cm soil depths. Cluster analysis was used to classify the samples based on the floristic composition data. Also detrended correspondence analysis (DCA) method was employed to assess the relationship between vegetation and environmental variables. There was no significant difference in terms of species richness, and diversity between mixed beech stands and hornbeam stands, but cluster analysis indicated that these stands were separated in two different groups based on herb layer species composition. DCA results showed that litter thickness, soil texture, total nitrogen, and organic carbon in the first layer were considered effective environmental variables in the distribution of sample plots in two stands. We observed that tree layer composition and soil characteristics were crucial contributors to variations of understory species composition which may be changed by forest management approaches over time. Tree layer composition and soil attributes can be considered effective factors for controlling and assessment of understory plant species composition. These findings could provide guidelines for conserving plant species diversity within any framework of sustainable forest management in Hyrcanian forests.
... Previous studies (e.g. Cleveland et al., 2006;Kaspari et al., 2008;Guendehou et al., 2014) have documented that the decomposition in temperate ecosystems is influenced by the forest floor N and P contents and the C/N ratio. Sariyildiz and Anderson (2005) described that beech forest floors contain more nitrogen at the final stage of development. ...
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Native to Eurasia, Eastern Europe, and Western Asia, Oriental beech (Fagus orientalis Lipsky) stands extend from the northwestern part of Turkey, the eastern part of the Caucasus Mountains in Georgia and Russia to the Alborz Mountains in Iran. The effect of different development stages of beech stands on the forest floor and soil characteristics are so far almost unknown. For this purpose, the Langa forest that is located in northern Iran was investigated to detect the effect of forest development on major traits of soil biology and related soil characteristics. For this aim, 45 forest floors and soil samples (15 samples per each development stage i.e. initial, optimal, and decay stage) were analysed. In addition, the water content, temperature, and biological dynamics were monitored over the different development stages in summer and fall. Among the considered independent factors, the development stage of beech had the largest explanatory power for the variations of the soil water content (34.7%), total earthworm density and biomass (29.6% and 32.3%, respectively), Acarina (30.3%), nematode (64.3%), protozoa (57.7%), bacteria, (62.8%), fungi (59.5%), basal respiration (53.0%), substrate-induced respiration (53.8%), microbial biomass carbon (30.4%), microbial biomass nitrogen (36.0%), microbial biomass phosphorous (59.1%) and net nitrification rate (19.1%). Soil temperature (42.5%), collembola density (18.2%), net ammonification rate (29.9%), and net N mineralization rate (2.1%) were predominantly determined by the seasons. With the ageing of the forest stands, soil fertility, biota abundance, and soil function were enhanced. To figure out the most vital soil features affecting C and N sequestrations, a stepwise regression model was applied. Carbon sequestration correlated positively to N, the C/N ratio, and negatively to porosity, and the nematode abundance. In addition, nitrogen sequestration correlated positively to C, the sand content, and fine root biomass and negatively to the C/N ratio, soil porosity, and aggregate stability. Although all forest stages of the Oriental beech have an important ecological role and their place in the evolutionary process, the old-growth (i.e. decay) stage is especially important for the soil functions exhibiting the highest fertility and biological relevance. The understanding of ecological changes within different development stages can be helpful in forest management and the evaluation of silvicultural methods.
... In the cycling of such nutrient, the decomposition processes have a crucial role by releasing complex organic compound into the simple usable form for proper growth and development of plants (Saha et al., 2016). Litter has thus occupied the attention of ecologists as it is an important factor in ecosystem dynamics to determine ecological productivity and may be useful in predicting soil fertility (Guendehou et al., 2014). ...
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Leaf litter decomposition in terrestrial ecosystems has a major role in recycling the nutrients to the soil. Various biotic (microorganisms) and abiotic (temperature, rainfall, humidity, seasonal variations) factors affect the rate of litter decomposition. This paper aims to compare leaf litter decomposition and weight loss pattern of five tropical tree species, and assess the effect of temperature and rainfall to the decomposition. A leaf litter bag method was used to assess the decomposition pattern for one year. Both decomposition rate constant (k), and weight loss were highest for Mallotus philippensis (% weight loss = 73.49; k = 0.33) and lowest for Shorea robusta (% weight loss = 54.01; k = 0.18). The study showed a significant positive correlation between decomposition rate constant (k) and temperature (p = 0.000; r = 0.54) and rainfall (p = 0.000; r = 0.51). The rate of leaf litter decomposition is primarily governed by biological organisms which in turn, get largely affected by climatic condition, especially temperature and precipitation, and litter quality. Thus, there is a need to analyze properties of leaf litter while using them as compost to get better production.
... branches (fine-woody) was determined from the litter of the dominant species (Podocarpus falcatus and Juniperus procera) of Chilimo forest (N 9.07, E 38.15), according to the chemical fractionation method of (Guendehou et al., 2014;Vávrová et al., 2008), see Table S2. Thereafter, the Yasso07 model was driven for 1,000 years to estimate the equilibrium SOC (when litter input equals soil respiration). ...
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Contributions from all land‐uses are needed when Ethiopia fulfils its Paris Agreement targets. The magnitude of soil carbon stock and the role of Ethiopian forest soils in climate change mitigation has not yet been clarified. In this study, soil carbon inventory in forests was carried out as a part of the Ethiopia REDD+ program. The performance of soil carbon models Yasso07 and CENTURY was tested by comparing the model predictions with the empirical soil organic carbon (SOC) data provided by the field inventory. In addition to that, global soil organic carbon map estimates by FAO for Ethiopia were included in the comparison. The soil inventory was carried out in 2017–2018 at a subset of permanent sampling units (SU) of the national forest inventory (NFI) conducted in 2014–2017. A combination of soil inventory data, soil carbon models and satellite images enabled to quantify the impact of forest use intensity to future SOC sinks in Ethiopian forests in a novel way. The Yasso07 and CENTURY models provided similar SOC estimates to the measured data for all biomes, and the GSOC map overestimated in biomes with larger SOC stocks. Results showed that Moist Afromontane (MA) forest biome contains twice as much SOC per unit area compared to Combretum‐Terminalia (CT) forest biome and three times more SOC compared to Acacia‐Commiphora (AC). Results underlined that sustainable forest management has a high potential for soil carbon development in Ethiopian forests in near future, impacting the ability of the country to achieve its Paris Agreement targets.
... In branch, carbon content was higher in DM (43.54) and SM (41.57). Carbon content was reported in tropical forest discussed by a different author(Singh and Mudgal, 2000;Kraenzel et al., 2003;Petsri et al., 2007;Guendehou et al., 2014;Paudel et al., 2015). Eigen values in three axes were observed 3.66, 0.65 ...
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We investigated assessment of essential and non-essential nutrients in soil along with litter chemistry in the tropical deciduous forest at Katerniaghat Wildlife Sanctuary, India. Three forest communities in teak plantation (TP), sal mixed (SM) and dry mixed (DM). The factors examined were nutrients contents chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel(Ni), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), molybdenum (Mo), cadmium (Cd), lead (Pb) and carbon in soil and litter. Majorly of essential nutrients levels were higher in the DM followed by SM and TP in soils. Zn was increased in TP, while Cu in SM soils at the depth of 0-15cm. Overall litter nutrients, concentration was maximum in DM. But some litter nutrients as like Ni and Zn maximum in the SM and TP. TOC was maximum in SM (19.23 g kg–1) followed by DM (17.74 g kg–1) and TP (13.62). Litter C was also increased in DM followed by SM and TP.
... Sustained nutrient cycling with faster turnover of litter through its decomposition regulates forest productivity (Vendrami et al., 2012). Decomposition of litter regulates soil fertility through soil organic matter production and nutrient cycling (Guendehou et al., 2014). Decomposition of litter is influenced by soil organisms, soil and climatic conditions and the nature and composition of litter (Bargali et al., 2015). ...
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Plant litter production and decomposition is a crucial ecosystem process that defines and governs the plant-soil relationships by regulating the nutrient turnover and the build-up of soil organic matter. Litter is the principal source of organic matter for soils in the forest ecosystem. The litter, upon decomposition , makes available essential nutrients for the growth and development of a forest stand. Different tree components contain different amounts of nutrients; and build up of soil organic matter. The amount of nutrients added through litter decomposition varies with forest types, species, stand attributes, and variation in seasonal environmental conditions. Nutrient return from organic matter is estimated by the physico-chemical properties of the litter. Moreover, the rate of decomposition and the nutrient releases are highly influenced by magnitude of litter produced, litter quality and nutrients release, as well as, by climatic conditions and existing microbial communities in the soil system. Ecological impact of carbon and nutrient dynamics in the litter layer is considerable in a forest ecosystem.
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Moso bamboo (Phyllostachys pubescens) forest is one of the important terrestrial forest ecosystems with a high potential for carbon fixation. However, the estimation of carbon storage in Moso bamboo stands has shown great variation in methods and results. A detailed field survey of 27 plots (10 m × 10 m) was conducted to investigate carbon storage of pure Moso bamboo stands in Jian-ou city, a typical bamboo site in Fujian province of China. Bamboo biomass was estimated using an allometric equation based on diameter at breast height (DBH) and age, which was validated with measured data in situ. Aboveground litter and soil (0 - 60 cm) samples were collected and measured on the basis of area. Results showed the biomass carbon of Moso bamboo was approximately 14.0 kg culm-1 of which the bamboo culm accounted for 60%. Total biomass carbon storage was calculated as 54.6 Mg ha-1 on average in the study site. Soil carbon storage was approximately 90.6 Mg ha-1 within the soil layer from 0 to 60 cm. The carbon storage of Moso bamboo stands in Jian-ou was estimated to be 145.3 Mg ha-1 in total. According to the age distribution of stands, the annually yielded carbon removed by harvest was estimated to be 3.97 Mg ha-1 yr-1 accounting for 7.3% of the total bamboo biomass carbon. Based on the bamboo area, the total carbon storage in bamboo stands in Jian-ou city was estimated to be 12.49 Tg C and extrapolated to China 842 Tg C. Carbon storage in Moso bamboo stands was not high compared to other forests, but the high yielded carbon removed by harvest annually implies a great growth rate and relatively high potential for carbon fixation. The contribution of Moso bamboo stands to carbon stabilization merits further study and should be recognized.
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I used the natural gradient of plant species richness from Brazilian Pantanal to verify how plant richness and structure are related to litter mass accumulated (LMA) in the soil. Significant positive effects on LMA and on its spatial stability highlight the trait-dependent insurance in environments under cyclic disturbances. I suggest that LMA is regulated by the relationship between colonization and performance of few plant species aboveground, which also explains the species distribution in the landscape. Pantanal is one of the most interesting and diverse biomes in the biosphere, and because of its high conservation appeal and natural experimental potential, studies therein may help to predict the effects of biodiversity loss on ecosystem functioning in natural environments.
Article
The forest ecosystem plays a key role in mitigating global climate change through carbon sequestration in its biomass and soils to limit the rising atmospheric concentration of CO2. However, the combined overall interaction of climate and forest type on the quantities and forms of soil carbon (organic vs. inorganic) has not yet been sufficiently investigated. In this study, the contents of soil total carbon (STC), soil organic carbon (SOC) and soil inorganic carbon (SIC) were measured along the 4000 km North-South Transect of Eastern China. We sampled 252 soil samples (6 replicates for each site, 3 depths for each site) from four long-term ecosystem experimental stations in Dinghushan, Shennongjia, Beijing and Changbaishan, along the transect from south to north, including 14 different forest types. The contents of STC, SOC, and SIC in the upper 60 cm soil layer varied in different types of forest with 34–107 g C kg⁻¹, 31–104 g C kg⁻¹, and 1.5–8 g C kg⁻¹, respectively. The northern fir and birch forest, most notably in Changbaishan, had the highest STC and SOC contents. The higher SIC contents were found in the southern evergreen broad-leaved forests in Dinghushan and Shennongjia. The contents of STC, SOC and SIC differed significantly in terms of mean annual temperature (MAT), mean annual precipitation (MAP), forest type, and soil depth. In the upper 60 cm soil layer, the most significant correlations occurred between SOC (or STC) and MAT (R²SOC = −0.62, R²STC = −0.60) when compared with the correlation between SOC (or STC) and MAP (R²SOC = −0.45, R²STC = −0.45) or elevation (R²SOC = 0.48, R²STC = 0.48). The soil stratification ratio (SR) of STC and SOC were typically ∼2–3 in most forests and even reached 5– 7 in Changbaishan forest, indicating a well-functioning ecosystem overall. We concluded that on the near-continental scale (4000 km), forest soil carbon contents and forms (SOC, STC, SIC) were controlled most strongly by temperature (MAT). Therefore, an innovative selection of a specific forest type (fir or broad-leaved forest) within set temperature regimes can better contribute to maximizing soil carbon content and thus optimize its sequestration on the national to near-continental scale to mitigate climate change.
Poster
This poster deals with the carbon footprint of agriculture in a humid savanna of West Africa. Specifically, it reports on the agronomic and environmental impact of the pantropical invasive weed Chromolaena odorata (Asteraceae).
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Natural ecosystem conversion to agriculture is known to alter soil carbon dynamic. Following such conversion in many tropical areas, land undergoes fallow-cropping cycles where fallows are invaded by the pantropical weed Chromoleana odorata. This study was undertaken in the forest-savanna interface area of Côte d’Ivoire to evaluate the impact of these cycles on soil carbon stocks (SOCS) and yam yields, decades after natural ecosystem conversion. Trials involved four treatments including yam farms in forest (FOR, n = 10), in forest-derived C. odorata fallows (FoDCo, n = 7), in savanna (SAV, n = 3) and in savanna-derived C. odorata fallows (SaDCo, n = 3). Prior to turning plots to farms, soil was sampled in the 0–10, 10–20 and 20–40 cm layers for physical, chemical and microbial parameters. Since forest and savanna soils were different in granulometry, FoDCo was compared to FOR, and SaDCo to SAV. The soil organic matter and nutrient concentrations in the 0–10 cm soil layer in FoDCo and FOR were similar, except for available P which was higher in the former. SaDCo was higher than SAV in terms of SOC, available P, mineral N, and NO3-N:Mineral N ratio. With regard to SOCS, value in FoDCo equalled that in FOR regardless of soil layers (63.2 ± 4.4 and 63.7 ± 4.6 Mg ha⁻¹ in 0–40 cm layer, respectively). However, SOCS significantly increased in SaDCo relative to SAV in the 0–20 cm (31.4 ± 2.7 vs. 24.2 ± 2.1 Mg ha⁻¹). Consistently, yam yield in FoDCo was like that in FOR while it doubled in SaDCo compared to SAV, with SOC, CEC and mineral N as the controlling factors. The major finding of this study is that the predominance of C. odorata in fallow phases allows at least for maintenance of SOCS and yam yields decades after natural ecosystem conversion to farmland. Furthermore, evidence of the feasibility of the “4 per mille” was given. These results are highly useful in forest protection strategies since farmers usually cut forest for yam cropping.
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This study was conducted to determine how the litter quality and decomposition of nine species (Acacia auriculiformis, Albizia zygia, Azadiractha indica,Baphia nitida, Gliricidia sepium, Leucaena leucocephala, Tithonia diversifolia, Senna spectabilis and Zea mays) influence soil N availability, microbial biomass and β-glucosidase activity during soil fertility improvement. The results on plant residue chemistry showed significant differences among species with N concentration ranging from 12.2 g kg⁻¹ in Z. mays to 39.2 g kg⁻¹ in B. nitida.C/N ratio was greatest in Z. mays (34.4) while lignin and polyphenol concentrations were greatest in A. auriculiformis. The highest decomposition rate (0.251% day⁻¹) occurred in T. diversifolia and least in A. auriculiformis, A. zygia, B. nitida and Z. mays with half-lives of between 28 – 56 days. Similar to the results on decomposition, between 80 to 89% of N, P, K, Ca and Mg were released from T. diversifolia within 7 days compared with more than 70% retention in A. auriculiformis, B. nitida and Z. mays. Moreover, the half-lives of decomposition and nutrient release of G. sepium, L. leucocephala, A. indica and S. spectabiliswere within 14 days. Mineral N, soil microbial biomass and β-glucosidase activities increased in all treatments with T. diversifolia recording the greatest effect. While N mineralization occurred in all species throughout the experiment, an initial N immobilization was recorded in A. zygia, B. nitida, A. auriculiformis and Z. mays treatments for up to 14 days. Further, the results showed the decomposition, nutrient release rates, mineral N, soil microbial biomass and β-glucosidase activities were dependent on litter quality. Phosphorus, lignin, lignin/N ratio and (lignin + polyphenol)/N ratio were most influential based on significant (p = 0.05) results.
Article
Natural ecosystem conversion to agriculture is known to alter soil carbon dynamic. Following such conversion in many tropical areas, land undergoes fallow-cropping cycles where fallows are invaded by the pantropical weed Chromoleana odorata. This study was undertaken in the forest-savanna interface area of Côte d'Ivoire to evaluate the impact of these cycles on soil carbon stocks (SOCS) and yam yields, decades after natural ecosystem conversion. Trials involved four treatments including yam farms in forest (FOR, n = 10), in forest-derived C. odorata fallows (FoDCo, n = 7), in savanna (SAV, n = 3) and in savanna-derived C. odorata fallows (SaDCo, n = 3). Prior to turning plots to farms, soil was sampled in the 0-10, 10-20 and 20-40 cm layers for physical, chemical and microbial parameters. Since forest and savanna soils were different in granulometry, FoDCo was compared to FOR, and SaDCo to SAV. The soil organic matter and nutrient concentrations in the 0-10 cm soil layer in FoDCo and FOR were similar, except for available P which was higher in the former. SaDCo was higher than SAV in terms of SOC, available P, mineral N, and NO 3-N:Mineral N ratio. With regard to SOCS, value in FoDCo equalled that in FOR regardless of soil layers (63.2 ± 4.4 and 63.7 ± 4.6 Mg ha −1 in 0-40 cm layer, respectively). However, SOCS significantly increased in SaDCo relative to SAV in the 0-20 cm (31.4 ± 2.7 vs. 24.2 ± 2.1 Mg ha −1). Consistently, yam yield in FoDCo was like that in FOR while it doubled in SaDCo compared to SAV, with SOC, CEC and mineral N as the controlling factors. The major finding of this study is that the predominance of C. odorata in fallow phases allows at least for maintenance of SOCS and yam yields decades after natural ecosystem conversion to farmland. Furthermore, evidence of the feasibility of the "4 per mille" was given. These results are highly useful in forest protection strategies since farmers usually cut forest for yam cropping.
Article
Litter production plays an important role in the functioning of the ecosystem, providing several ecosystem services, such as nutrients cycling and carbon storage. We studied litter production patterns and its relationship with forest structure over a chronosequence of secondary forests in southern Bahia, Brazil. In the study area, 15 pairs of mature and secondary forest were used, in a chronological sequence, being 10, 25 and 40-year-old secondary forests and mature forests.Plots were created for the collection of aboveground biomass data, and within these plots, litter collectors were installed and monitored for 1 year. The results showed that litter production was lower in 10-year-old secondary forests when compared with older forests. On the other hand, in the 10-year-old forests, annual litter production represents 47.8% of the stored biomass, while in mature forests annual litter production represents only 4%. We found that structural variables (basal area, number of stems and canopy opening) influence significantly litter production, as well as litter as percentage of forest biomass. The study emphasizes the importance of biomass production through litterfall in regenerating tropical forests, and its importance for carbon storage and for the maintenance of ecosystem services.
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The chemical quality of soil carbon (C) inputs is a major factor controlling litter decomposition and soil C dynamics. Mycorrhizal fungi constitute one of the dominant pools of soil microbial C, while their litter quality is understood poorly, leading to the major uncertainties in estimating soil C dynamics. For the first time, we examined chemical recalcitrance of arbuscular mycorrhizal (AM) and ectomycorrhizal (EM) fungal species using fungal samples obtained from in vitro cultivation. We show that the chemical composition of AM and EM fungal mycelium differs significantly: EM fungi have higher concentrations of labile (water-soluble, ethanol-soluble) and recalcitrant (non-extractable) chemical components, while AM fungi have higher concentrations of acid-hydrolysable components. Our results imply that differences in chemical decomposability traits among mycorrhizal fungal guilds represent a critically important driver of the soil C cycle, which could be as vital as is recognized for differences among aboveground plant litter.
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The oxidative ratio (OR) of organic material integrates the ratio of CO2 sequestered in biomass vs. O2 produced over longer timescales, but the temporal and spatial variability within a single ecosystem has received very limited attention. Between October 2017 and October 2019, we repeatedly sampled leaves, twigs, bark, outer stem wood, understorey vegetation and litter in a temperate beech forest close to Leinefelde (Germany) for OR measurements across a seasonal and spatial gradient. Plant component OR ranged from 1.004 ± 0.010 for fine roots to 1.089 ± 0.002 for leaves. Inter- and intra-annual differences for leaf and twig OR exist, but we found no correlation with sampling height within the canopy. Leaf OR had the highest temporal variability (minimum 1.069 ± 0.007, maximum 1.098 ± 0.002). This was expected, since leaf biomass of deciduous trees only represents the signal of the current growing season, while twig, stem and litter layer OR integrate multiple years. The sampling years 2018 and 2019 were unusually hot and dry, with low water availability in the summer, which could especially affect the August leaf OR. Total above-ground OR is dominated by the extremely stable stem OR and shows little variation (1.070 ± 0.02) throughout the two sampling years, even when facing extreme events.
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We evaluated the applicability of the dynamic soil carbon model Yasso07 in tropical conditions in West Africa by simulating the litter decomposition process using as required input into the model litter mass, litter quality, temperature and precipitation collected during a litterbag experiment. The experiment was conducted over a six-month period on leaf litter of five dominant tree species, namely Afzelia africana, Anogeissus leiocarpa, Ceiba pentandra, Dialium guineense and Diospyros mespiliformis in a semi-deciduous vertisol forest in Southern Benin. Since the predictions of Yasso07 were not consistent with the observations on mass loss and chemical composition of litter, Yasso07 was fitted to the dataset composed of global data and the new experimental data from Benin. The re-parameterized versions of Yasso07 had a good predictive ability and refined the applicability of the model in Benin to estimate soil carbon stocks, its changes and CO2 emissions from heterotrophic respiration as main outputs of the model. The findings of this research support the hypothesis that the high variation of litter quality observed in the tropics is a major driver of the decomposition and needs to be accounted in the model parameterization.
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Decomposition and nutrient release patterns of prunings of three woody agroforestry plant species (Acioa barteri, Gliricidia sepium and Leucaena leucocephala), maize (Zea mays) stover and rice (Oryza sativa) straw, were investigated under field conditions in the humid tropics, using litterbags of three mesh sizes (0.5, 2 and 7 mm) which allowed differential access of soil fauna. The decomposition rate constants ranged from 0.01 to 0.26 week−1, decreasing in the following order; Gliricidia prunings >Leucaena prunings > rice straw > maize stover >Acioa prunings. Negative correlations were observed between decomposition rate constants and C:N ratio (P < 0.004), percent lignin (P < 0.014) and polyphenol content (P < 0.053) of plant residues. A positive correlation was observed between decomposition rate constant and mesh-size of litterbag (P < 0.057). These results indicate that both the chemical composition of plant residues and nature of the decomposer played an important role in plant residue decomposition.Nutrient release differed with quality of plant residues and litterbag mesh-size. Total N, P, Ca and Mg contents of plant residues decreased with time for Gliricidia and Leucaena prunings, maize stover, and rice straw, and increased with time for Acioa prunings. There was some indication of N immobilization in maize stover and rice straw; P immobilization in Leucaena prunings and rice straw; and Ca immobilization in maize stover, rice straw and Gliricidia and Leucaena prunings. Acioa prunings immobilized N, P, Ca and Mg. All plant residues released K rapidly. Nutrient release increased with increasing mesh-size of litterbags, suggesting that soil faunal activities enhanced nutrient mobilization.
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In this study, we investigated the woody species diversity and community characteristics of natural forests and arecanut agroforests of south Meghalaya, Northeast India. A total of 117 tree species (≥ 5 cm dbh) belonging to 98 genera were identified in the natural forests and 83 tree species, belonging to 62 genera were identified in the arecanut agroforests. In natural forests, Lauraceae (18 species), Euphorbiaceae (16 species) and Fagaceae (11 species) were the dominant families. In the case of arecanut agroforests, Euphorbiaceae (16 species), Lauraceae (14 species) and Moraceae (11 species) were the dominant families. Arecaceae was the only monocot family represented by Caryota spp. in both natural forests and arecanut agroforests, and there was only one gymnospermic family (Pinaceae) recorded only in the natural forests. Arecanut agroforests are less diverse and less dense than the natural forests. In arecanut agroforests, the density of economically important species was significantly higher indicating deliberate promotion of such species.
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The palynological study was carried out in three sediment cores one each from centripetal perennial lakes in Talbehat (depth 1.0 m; 25° 0' 10'' N and 78° 26' 20'' E), Madaura (depth 0.8 m; 24° 22' 35'' N and 78° 48' 9'' E) and Dhaura (depth 1.2 m; 24° 17' 40'' N and 78° 51' 8'' E) flanked at three corners of the Lalitpur district, Uttar Pradesh, in order to understand the climate and vegetation pattern during late holocene. Three pollen zones could be identified indicating the succession of vegetation from Moist Deciduous Forest (~4000 yrs BP) to Mixed Deciduous Forest (~2000 yrs BP) and finally to Dry Deciduous Forest since ~1400 yrs. BP. Dominance of Shorea, Hopea in the beginning of late holocene along with other moisture loving tree taxa and their decline since ~1400 yrs BP indicate an increase in aridity/weakened monsoon. However, the diversification of vegetation since the last millenium in the study area is unlike the reduction in tree taxa recorded during the same period from the fertile Gangetic plain. This difference is attributed to (1) gradual nutrient enrichment and accumulation of insitu undisturbed soil cover in time, retaining more soil moisture during monsoons, and (2) slow pace of agricultural development due to rugged, undulating terrain resulting into lower anthropogenic pressure compared to the Gangetic plain.
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We compared vegetation structure and floristics among degraded tropical secondary forests on China's Hainan Island, representing two successional stages (SF1 and SF2), and a primary forest to provide information that would support restoration process. We observed no significant differences in total tree density among the forest types, but the total basal area was significantly higher in primary forest. Stem size class distribution differed significantly between the primary and secondary forests, but the two secondary forests did not differ significantly. SF1 was dominated by Macaranga denticulata and SF2 by Cratoxylon ligustrinum, whereas the primary forest by Engelhardtia chrysolepis. The Simpson and Shannon diversity indices were greater for primary forest than for secondary forests. Jaccard's similarity coefficient and the Morisita-Horn index indicated greater similarity between the two secondary forests and the lowest similarity between SF1 and the primary forest. Understanding the structural and floristic characteristics of different successional stages is important for managing forest restoration process.
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Rothc-26.3 is a model of the turnover of organic carbon in non-waterlogged soils that allows for the effects of soil type, temperature, moisture content and plant cover on the turnover process. It uses a monthly time step to calculate total organic carbon (t C ha-1), microbial biomass carbon (t C ha-1) and Δ14C (from which the radiocarbon age of the soil can be calculated) on a years-to-centuries timescale (Jenkinson, 1990; Jenkinson and Coleman, 1994; Jenkinson et al., 1987; Jenkinson et al., 1991; Jenkinson et al., 1992). It needs few inputs and those it needs are easily obtainable. It is an extension of the earlier model described by Jenkinson and Rayner (1977), and by Hart (1984). Needless to say, it has many ideas in common with other contemporary turnover models, notably CENTURY (Parton et al., 1988) and Van Veen and Paul’s model (Van Veen and Paul, 1981).
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A general model is presented in which the dynamics of decomposition in terrestrial ecosystems are determined by a set of hierarchically organized factors which regulate microbial activity at decreasing scales of time and space in the following order: climate - clay mineralogy + nutrient status of soil - quality of decomposing resources - effect of macroorganisms (i.e., roots and invertebrates). At the lower scale of determination, biological systems of regulation based on mutualistic relationships between macro- and microorganisms ultimately determine the rates and pathways of decomposition. Four such systems are defined, i.e., the litter and surface roots system, the rhizosphere, the drilosphere and the termitosphere in which the regulating macroorganisms are respectively litter arthropods and surface roots, live subterranean roots, endogeic earthworms, and termites. In the humid tropics, this general model is often altered because climatic and edaphic constraints are in many cases not important and because high temperature and moisture conditions greatly enhance the activity of mutualistic biological systems of regulation which exert a much stronger control on litter and soil organic matter dynamics. This general hypothesis is considered in the light of available information from tropical rain forests and humid savannas. Theoretical and practical implications regarding the biodiversity issue and management practices are further discussed. It is concluded that biodiversity is probably determined, at least partly, by soil biological processes as a consequence of enhanced mutualistic interactions, which enlarge the resource base available to plants. It is also concluded that any effort to restore or rehabilitate degraded soils in the humid tropics is promised to fail unless optimum levels of root and invertebrate activities are promoted and the resulting regulation effects operate in the four abovedescribed biological systems of regulation. Research required to substantiate and adequately test the present set of concepts and hypotheses are expressed.
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Decomposition of Scots pine needle litter originating from five stands treated with different amounts of nitrogen fertilizer was measured over a 4-year period in a mature Scots pine forest. The litter types, which differed in initial concentrations of nitrogen, phosphorus, potassium, and sulfur, but not in gross organic composition, were studied with respect to mass loss, ingrowth of total fungal mycelium, and net release of nutrients. During the first year of decomposition, rates of mass loss and ingrowth of fungal mycelium were highest in the nutrient-rich litter. Phosphorus concentration was found to be the main factor affecting mass-loss rate, and the rate of fungal ingrowth was positively correlated with initial nitrogen concentration. After this initial period, decomposition rates decreased, and after 4 years, accumulated mass loss and amounts of fungal mycelium were similar in all five litter types. These findings may be due, in part, to a lower rate of lignin decomposition in nitrogen-enriched litter. Of the elements, potassium and magnesium were most rapidly lost from the litter, and their release was most pronounced during the first year. Calcium release was proportional to the loss in organic matter. Initially, the release of nitrogen and phosphorus was positively related to their concentrations in litter, however, during later stages of decomposition the differences among litter types levelled out. There was a tendency for concentrations of all elements, except nitrogen, in the different litters to approach similar levels as decomposition proceeded. Thus, after 4 years the nutrient composition of the various litter types was very similar, except for higher nitrogen concentrations in the originally most nutrient-rich litters. The importance of the results in terms of substrate quality in fertilized as well as in non-fertilized forests is discussed.
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The feedback between plant litterfall and nutrient cycling processes plays a major role in the regulation of nutrient availability and net primary production in terrestrial ecosystems. While several studies have examined site-specific feedbacks between litter chemistry and nitrogen (N) availability, little is known about the interaction between climate, litter chemistry, and N availability across different ecosystems. We assembled data from several studies spanning a wide range of vegetation, soils, and climatic regimes to examine the relationship between aboveground litter chemistry and annual net N mineralization. Net N mineralization declined strongly and non-linearly as the litter lignin:N ratio increased in forest ecosystems (r 2 = 0.74, P < 0.01). Net N mineralization decreased linearly as litter lignin concentration increased, but the relationship was significant (r 2 = 0.63, P < 0.01) only for tree species. Litterfall quantity, N concentration, and N content correlated poorly with net N mineralization across this range of sites (r 2 < 0.03, P = 0.17–0.26). The relationship between the litter lignin:N ratio and net N mineralization from forest floor and mineral soil was similar. The litter lignin:N ratio explained more of the variation in net N mineralization than climatic factors over a wide range of forest age classes, suggesting that litter quality (lignin:N ratio) may exert more than a proximal control over net N mineralization by influencing soil organic matter quality throughout the soil profile independent of climate.
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We studied the influence of litter quality on the decomposition rate of leaves from nine Mediterranean shrubs and trees using litter bag methods for a 2-yr period at two ecosystems in southwest Spain. Linear and nonlinear regressions were calculated between mass loss and the concentrations of the major organic and inorganic constituents of leaves (lignin, cutin, cellulose, tannins, crude fat, soluble carbohydrates, nitrogen, and phosphorus) and between mass loss and leaf toughness in order to determine the best predictor of leaf litter decomposition in these ecosystems. In addition, ratios between some of the litter quality parameters were examined as mass loss predictors. Loss of soluble components from leaves was used to define two phases of decomposition: a leaching phase that lasted 2-4 mo and a postleaching phase. Leaf toughness and the ratio of toughness: phosphorus concentration were the best indicators of mass loss during the leaching phase in both ecosystems, and cutin: nitrogen or cutin: phosphorus ratios were the best predictors of mass loss in the postleaching phase, but only in the drier and more nutrient-poor ecosystem. When the two phases were combined, leaf toughness, toughness: nitrogen, and/or cutin: nitrogen significantly explained the mass loss in both ecosystems.
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1 Vegetative responses of Empetrum hermaphroditum, Vaccinium vitis-idaea, V. uliginosum and V. myrtillus to environmental change (temperature (T), water (W) and fertilizer (F)) were investigated in a factorial field perturbation study in sub-Arctic Sweden over two growing seasons (1991 and 1992). 2 Total above-ground biomass was largely unresponsive to the perturbations due to dilution of current season's growth by material produced in previous years. 3 The mass of shoot material produced in 1991, increased in response to F within 11 weeks of the start of the experiment in the two evergreen species (V. vitis-idaea and E. hermaphroditum), but not in the only deciduous species (V. uliginosum) measured that year. All three species studied in 1991 were unresponsive to T and W. 4 In all four species the mass of shoot material produced in 1992 showed the greatest response to F. The order of sensitivity was V. myrtillus > V. uliginosum > V. vitisidaea > E. hermaphroditum. T treatments also resulted in greater shoot mass (V. vitisidaea > E. hermaphroditum > V. myrtillus > V. uliginosum). No significant responses to W alone were observed. 5 T and F frequently interacted synergistically on the shoot characteristics measured in 1992. 6 The treatments affected the biomass allocation of the species differently, and this relates to their growth habit. Greater stem growth was observed in V. uliginosum and E. hermaphroditum, both of which spread laterally by producing long above-ground shoots. Greater leaf growth was observed in V. vitis-idaea and V. myrtillus, which spread laterally by rhizomes.
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Mass loss and changes in chemical composition during the decay of a variety of forest litters decomposing at several very different sites were measured. -from Authors
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Aim: To investigate broad-scale patterns of plant leaf ash content and their possible causes in China. Location: Mainland China and Hainan island, with the geographic ranges for the data used from 18.7° N to 49.2° N and 76.0° E to 128.3° E. Methods: By analysing a data set of 2022 leaf samples, involving 704 species of terrestrial plants. Results: Leaf ash content increases with increasing latitude at an average rate of 2.7 mg ash g -1 dry weight per degree latitude from south to north of China. Plant functional group shows a more powerful influence on the spatial variation in leaf ash than soil pH and climate. Fast-growing species or those with leaves with a short life span have higher leaf ash than slow-growing species or those with a long leaf life span. Plants from alkaline soils have higher leaf ash than those from acid soils (39.5 mg g -1 increase in leaf ash content per unit increase of pH). Increasing precipitation significantly reduces leaf ash (with a mean rate of 4.8 mg g -1 for every 100 mm rainfall), whereas the effect of temperature appears to be nonlinear. Main conclusions: This study shows a significant latitudinal trend in leaf ash content in