Litter Ca Research Articles

Diversidade de Trichocomaceae Isolada de Solo e Serrapilheira de Floresta Atlântica

The purpose of the present study was to assess the diversity and succession of family Trichocomaceae in areas with different levels of human disturbance, namely, most impacted area and least impacted area. This research was carried out in Parque Natural Municipal Curio (Natural City Preserve) in Paracambi, State of Rio de Janeiro. Two areas with different levels of human disturbance were selected and, in each of these areas, a 1,000 m2 plot was delimited, where soil and leaf litter samplings were collected for fertility and mycobiota assessment. In general, the most impacted area presented the highest values for pH, Ca and K. The highest values of leaf litter yield were also observed in this area, which contributed to the higher values of K - an element easily leachable in mulch. The highest values of Colony Formation Units (CFU) in soil and litter: 5.4 × 104 and 9 × 104, respectively, were observed in the most impacted area. This area also presented the highest values for Ca in soil and litter, which suggests that this nutrient may contribute to the greater number of CFUs. For the least impacted area, the CFU values were between 4 × 104 for litter and 5 × 104 for soil; no clear association was observed between the higher number of CFUs and the concentrations of nutrients in soil and/or litter. The total number of fungi isolated was 87, belonging to four different genera and 22 species, with 16 Penicillium spp., four Aspergillus spp., one Paecilomyces sp. and one Trichoderma sp. No clear association was noticed between climatic variables and the number of CFUs. The greatest amount of CFUs was observed in the most impacted area, both in soil and leaf litter. The higher concentration of Ca quantified in this area suggests that this nutrient may be contributing to the increase in CFUs. The genera Penicillium spp. was the most representative fungus in both areas.

Terrestrial gastropod responses to an ecosystem-level calcium manipulation in a northern hardwood forest

The effects of acid deposition on soil calcium (Ca), and in turn on land snail populations, have been of heightened concern for several decades. We compiled a 10 year record (1997–2006) of gastropod abundance on two small watersheds at the Hubbard Brook Experimental Forest, one of which was treated with a Ca addition in 1999. In years 3–7 post Ca addition, snail abundance in the treated watershed was 73% higher than in the reference area (p < 0.001); there was no significant difference in the 3 years prior to treatment, and no significant difference in slug abundance in any year. We analyzed relationships between snail density and microsite spatial variation in leaf-litter Ca concentration, litter-layer thickness, tree species composition, slope, dead wood, and forest-floor light level. We found that snail abundance was significantly correlated with litter Ca concentration (p < 0.001) and negatively correlated with the importance value of American beech (p = 0.05). Isotopic-tracer analysis indicated that, on average, 76% of Ca in snail shells 5 years post treatment was derived from the added Ca. However, interannual variation in snail numbers indicates that other factors beyond available Ca have a strong influence on snail abundance.

Controls over leaf and litter calcium concentrations among temperate trees

Four-fold variation in leaf-litter Ca concentration among 14 tree species growing in a common garden in central Poland was linked to variation in soil pH, exchangeable Ca, soil base saturation, forest floor turnover rates, and earthworm abundance. Given the potential importance of tissue Ca to biogeochemical processes, in this study we investigated potential controls on leaf Ca concentrations using studies of both laboratory seedlings and 30-year-old trees in the field. We first assessed whether species differences in Ca concentration of green leaves and leaf litter were due to differences in Ca uptake, plant growth, or Ca translocation to different organs, by measuring seedlings of 6 of the 14 species grown under controlled conditions of varying Ca supply. We also investigated whether trees species with high Ca concentrations in green leaves and leaf litter access soil Ca to a greater extent than low-Ca species by growing more fine roots in high-Ca soil horizons. Root distribution in the field was determined in all 14 tree species by profile wall mapping and soil sampling of excavated pits. There was no correlation between horizon root count density (number of roots m−2) and exchangeable soil Ca, nor was there a correlation of stand-level leaf litter Ca with density of roots 45–100 cm deep in the soil, suggesting that a deeper root distribution does not result in greater Ca acquisition among these species. Variation among species in leaf Ca concentration of greenhouse seedlings was positively correlated with leaf Ca concentrations of mature trees, indicating that the same ranking in leaf Ca among species existed under controlled Ca supply. Species also differed in seedling growth response to Ca supply. Tilia, the species with the highest leaf Ca in the field, generated only 10% as much biomass and height at low relative to high Ca supply, whereas the other species exhibited no significant differences. Species exhibited differences in (i) partitioning of whole plant Ca and biomass to leaf, stem and root organs and (ii) the pattern of such partitioning between high and low Ca treatments. Our data support the hypothesis that although soil Ca supply can contribute to variation among trees in leaf and litter Ca concentration, innate physiological differences among species also can be a major cause for species variation.

Response of Broilers to Feeding Low-Calcium and Phosphorus Diets Plus Phytase Under Different Environmental Conditions: Body Weight and Tibiotarsus Mineralization

Three experiments on Ross broiler chickens were conducted in 3 locations: cages (Experiment 1), floor pens (Experiment 2), and commercial farms (Experiment 3). The effect of low-total P (TP) wheat-soybean based diets plus microbial phytase (Natuphos) was evaluated. Four experimental starter and finisher diets were used in a 2-phase feeding program, as follows: control diet (SC until 21 d, FC from 22 to 42 d); 2 diets (SL400 and SL600 until 21 d, FL400 and FL600 from 22 to 42 d) with low TP (0.61% for starter and 0.54% for finisher), including 400 and 600 U/kg of phytase, respectively; and a very low-TP (0.52% for starter and 0.44% for finisher) diet (SVL600 until 21 d, FVL600 from 22 to 42 d) with 600 U/kg of phytase. In Experiment 1 (broilers in cages had movement limitation and no access to litter), no differences in BW, tibiotarsus mineralization, or mineral metabolism were observed among diets. In Experiment 2 (broilers in floor pens had movement limitation and access to litter), at 21 d of age, the lowest tibiotarsus ash percentage and BW were shown by birds fed the SVL600 diet. At 42 d of age, broilers fed the FC diet were the lightest. For the rest of the parameters of tibiotarsus mineralization and mineral metabolism measured in Experiment 2, no differences were shown. In Experiment 3 (broilers in commercial farms had access to litter without movement limitation), the BW of broilers fed the SC diet was the highest at 21 d of age. At 42 d of age, the broilers fed FL400 and FL600 diets were the heaviest. At the end of Experiment 3, broilers fed the FC diet had the highest dry litter Ca and P, whereas broilers fed the FVL600 diet had the lowest values. In conclusion, the very low-TP wheat-soybean based diet supplemented with 600 U/kg of phytase was sufficient to optimize all the parameters measured in Experiment 1 but not in Experiments 2 and 3. Therefore, when evaluating Ca and P in phytase-supplemented diets for broilers, it is necessary to bear in mind the environmental conditions of experimentation.

TREE SPECIES EFFECTS ON DECOMPOSITION AND FOREST FLOOR DYNAMICS IN A COMMON GARDEN

We studied the effects of tree species on leaf litter decomposition and forest floor dynamics in a common garden experiment of 14 tree species (Abies alba, Acer platanoides, Acer pseudoplatanus, Betula pendula, Carpinus betulus, Fagus sylvatica, Larix decidua, Picea abies, Pinus nigra, Pinus sylvestris, Pseudotsuga menziesii, Quercus robur, Quercus rubra, and Tilia cordata) in southwestern Poland. We used three simultaneous litter bag experiments to tease apart species effects on decomposition via leaf litter chemistry vs. effects on the decomposition environment. Decomposition rates of litter in its plot of origin were negatively correlated with litter lignin and positively correlated with mean annual soil temperature (MAT(soil)) across species. Likewise, decomposition of a common litter type across all plots was positively associated with MAT(soil), and decomposition of litter from all plots in a common plot was negatively related to litter lignin but positively related to litter Ca. Taken together, these results indicate that tree species influenced microbial decomposition primarily via differences in litter lignin (and secondarily, via differences in litter Ca), with high-lignin (and low-Ca) species decomposing most slowly, and by affecting MAT(soil), with warmer plots exhibiting more rapid decomposition. In addition to litter bag experiments, we examined forest floor dynamics in each plot by mass balance, since earthworms were a known component of these forest stands and their access to litter in litter bags was limited. Forest floor removal rates estimated from mass balance were positively related to leaf litter Ca (and unrelated to decay rates obtained using litter bags). Litter Ca, in turn, was positively related to the abundance of earthworms, particularly Lumbricus terrestris. Thus, while species influence microbially mediated decomposition primarily through differences in litter lignin, differences among species in litter Ca are most important in determining species effects on forest floor leaf litter dynamics among these 14 tree species, apparently because of the influence of litter Ca on earthworm activity. The overall influence of these tree species on leaf litter decomposition via effects on both microbial and faunal processing will only become clear when we can quantify the decay dynamics of litter that is translocated belowground by earthworms.

EFFECTS OF FARGESIA DENUDATA DENSITY ON SEASONAL CHANGES IN LITTER NUTRIENT CONCENTRATIONS AND THEIR POTENTIAL RETRANSLOCATION

Dwarf bamboo (Fargesia denudata), a staple food of the giant panda, is the dominant synusia of the forest ecosystem in Wanglang National Nature Reserve, which plays an important role in the maintenance of forest ecosystem structure and function. The seasonal changes of nutrients in bamboo litter and nutrient retranslocation is one of the most profound ecological processes in the forest system. The seasonal change of nutrients in bamboo litter and nutrient retranslocation is regulated by the density of the bamboo stand as well as by biotic and abiotic factors. Although there have been a number of studies on nutrient cycling in bamboo forests, the effects of the bamboo density has not been investigated. The influence of bamboo density on the dynamics on litterfall, nutrient concentrations in bamboo litter, the differences in nutrient concentrations between litter and fresh leaves, and potential nutrient retranslocation were studied in three bamboo communities with different densities (D_1 with (220±11) stems·m -2, D_2 with (140±7) stems·m -2, and D_3 with (80±4) stems·m -2) beneath a bamboo-fir (Picea purpurea) forest. Plots were chosen that had similar slope, aspect, soil parent material and texture, tree canopy, etc. Bamboo litter was collected in each stand and fresh leaves collected over a growing period from May to October, 2003, and nutrient concentrations (C, N, P, K, Ca and Mg) analyzed. The results indicated that litterfall production of bamboo increased with stem density during the growing period. The concentrations of C, N, P and K in litter decreased with stem density, but Ca and Mg showed the opposite pattern. It was found that N, P and K concentrations were lower in litter than in fresh leaves, increased from May to July, and decreased after July. Carbon concentrations in both litter and fresh leaves did not vary with the stem densities and month. Calcium concentrations were higher in litter than in fresh leaves over the growing season, but there was no significant monthly variation. Litter had the lowest Mg concentrations in July (during the exponential growth period) whereas fresh leaves showed the opposite pattern. No significant monthly differences in nutrients were found among the three communities. The potential retranslocation capacity of P was strongly regulated by stem density, but N and K retranslocation was not influenced by stem density. The potential retranslocation capacity of N, P and K showed the ranked order as KNP. The retranslocation of C in bamboo was not significantly different among the three bamboo communities. The accumulation of Ca in litter increased with stem density. The accumulation of Mg in litter increased with stem density, but the retranslocation capacity decreased with stem density. Density, therefore, greatly influenced the seasonal changes of nutrient concentrations in litter and their potential retranslocation capacity.

Scattered paddock trees, litter chemistry, and surface soil properties in pastures of the New England Tablelands, New South Wales

Scattered paddock trees are widespread throughout rural Australia but their effect on soil conditions has received only limited research attention. This study investigated the influence of 3 Eucalyptus species on surface soil properties on different parent materials at both stocked and unstocked sites on the Northern Tablelands of New South Wales. Mineral soil samples to a depth of 5 cm were collected at intervals up to twice the canopy radius away from tree trunks and litter samples were collected at corresponding points. Mineral soils were analysed for pH (CaCl2), organic carbon (C), and extractable phosphorus (P) concentration, while for the litter samples, P, sulfur, cations, and ash alkalinity were determined. Stocking with sheep and cattle increased surface soil acidity and C and P concentrations at each location. However, soils under E. melliodora and E. viminalis showed higher pH and increased C and P concentrations close to the tree stem irrespective of grazing. Soils under E. caliginosa, while having similar patterns of C and P, showed variable acidity patterns with instances of lower pH close to the tree stem. Spatial patterns in soil acidity were associated with the ash alkalinity of litter, indicating litter as a source of alkalinity addition to the soil surface, although different patterns of soil pH could not be fully explained by litter ash alkalinity alone. The close correlation of litter Ca content with ash alkalinity suggests that this element might be a suitable indicator of the acid amelioration capacity of different tree species.

Nutrientes no mantilho em pastagem nativa sob distintos manejos

A avaliação da quantidade de nutrientes no mantilho é importante para verificar a ciclagem de nutrientes e a preservação da fertilidade do solo. O teor e a quantidade de nutrientes no mantilho e material senescente foram estudados em pastagem nativa sob pastejo, sujeita à queima e manejos alternativos, durante um ano, nos Campos de Cima da Serra, no Rio Grande do Sul. O acúmulo de mantilho foi coletado em gaiolas de exclusão ao pastejo, a cada 90 dias. O mantilho representou o material morto desprendido da planta existente junto à superfície do solo. A esta fração foi adicionado o material senescente ligado à planta. Os tratamentos foram pastagem nativa sob pastejo sem queima e sem roçada há 32 anos, melhorada há sete anos e com queima bienal há mais de 100 anos. O delineamento experimental foi completamente casualizado com três repetições. Os teores de Ca e Mg no mantilho mais material senescente foram inferiores no tratamento queimado em relação às áreas sem queima. O melhoramento da pastagem aumentou os teores de nutrientes nos tecidos. A quantidade acumulada de nutrientes, reflexo da produção de mantilho e material senescente, foi maior nos sistemas sem queima.

Phosphorus-leaching from litterfall in wetland catchments of the Swan Coastal Plain, southwestern Australia

Many wetlands of the Swan Coastal Plain in southwestern Australia have catchments with significant areas of native vegetation. The dynamics of P release from their litter and its significance as a P source for wetlands have not been previously investigated. Litterfall of common plant species were collected before the local rainy season, and examined for P leaching properties under inundated conditions. Inundation of `intact' litter materials for 24 hours leached 30±7.5% (95% confidence level) of this Tot-P in litter, measured by anion exchange membrane extraction. This increased to 46.9% of `apparent' P release at 115 days. The released P was incorporated into microbial biomass during leaching so modifying leachate concentrations. Using liquid chloroform `fumigation' it was estimated that 36.2 ± 15.6% (95% confidence level) of Tot-P leached during the 115-day inundation was in the microbial biomass pool, not directly measured by AEM extraction. P leaching during initial and prolonged inundation correlated with litter Ca, Mg and total base concentration, but the initial Tot-P concentration of litter was the best predictor for P leaching, in both short-term and prolonged inundation (R2 = 0.80 and 0.93, p < 0.0001). The high P leaching rate during 24 hours suggested that P from litter during `first storm' events could produce a significant P flux from local catchments and contribute nutrients to downstream wetlands.

Canopy leaching, dry deposition, and cycling of calcium in Austrian oak stands as a function of calcium availability and distance from a lime quarry

Three Austrian oak stands were chosen along a 4-km distance gradient from a lime quarry to study effects of Ca availability both on dry deposition rates and on Ca cycling in these ecosystems. A fourth stand was used as a more regional reference site, some 30 km west of the lime quarry. Calcium bulk precipitation fluxes decreased with increasing distance from the lime quarry, contributing to major differences in available Ca along the transect over the last decades. Higher supply of Ca changed biogeochemical cycling by increasing pool sizes and fluxes of Ca in foliage, litter, throughfall, forest floor, soil, herbaceous vegetation, and soil solution. Regression analyses of net throughfall was a useful tool for separating between dry deposition and leaching of Ca. Dry deposition rates of particulate Ca declined rapidly with increasing distance from the Ca source. Leaching of Ca from the canopy declined along the gradient according to Ca content of the green foliage during the growing season. Leaching rates as a percentage of the stand's annual requirement indicated a relative shift from solid (litter) toward more solute Ca fluxes reaching the forest floor with increasing Ca availability of the stand.

Nutrient stocks in managed and natural humid tropical fallows

Managed fallows which recover nutrients more rapidly than natural secondary vegetation may improve the performance of shifting agriculture systems operating under inadequately long fallow cycles. Our objective was to construct nutrient balances for the soil, vegetation, and litter compartments of six planted leguminous fallows and natural secondary vegetation during 53 months. The fallows were planted on a previously cultivated Ultisol (Acrisol) in the Peruvian Amazon and included:Centrosema macrocarpum (Centrosema),Pueraria phaseoloides (Pueraria),Stylosanthes guianensis (Stylosanthes),Desmodium ovalifolium (Desmodium),Cajanus cajan (Cajanus), andInga edulis (Inga). In addition, in the natural fallow treatment secondary vegetation was allowed to establish and grow naturally. Quantities of extractable P, K, Ca, and Mg, total N, and organic C in soil to a 45 cm depth, and macrouttrients in aboveground biomass, roots, and litter were estimated at fallow planting, at 8, 17, and 29 months afterward, and at fallow clearing (53 months). Total N stocks increased by 10% in the Stylosanthes, Desmodium, Pueraria, and Inga treatments, but changed little in the Cajanus, Centrosema and natural fallows. This difference was largely due to greater net increases in both soil and vegetation compartments in the former group of treatments. In the Inga, Desmodium, and natural fallows, total stocks of P and K at 53 months were about 40% to 80% greater and 12% greater, respectively, than initial values, but Ca and Mg stocks were reduced by 25% to 40%. In the other treatments, there was generally little change in P stocks, but large (30% to 60%) reductions in K, Ca, and Mg during the course of the fallow. Although there were net decreases of stocks of P, K, Ca, and Mg in soil in all treatments during the fallow, storage of P and K in vegetation and litter in the Inga, Desmodium, and natural fallows offset losses of these nutrients from soil. These treatments also tended to accumulate more Ca and Mg in biomass and litter than the other treatments. These results suggest that leguminous fallow vegetation that accumulates large amounts of biomass may increase N, P, and K stocks, but that incomplete recuperation of Ca and Mg may limit the sustainability of short-rotation fallow-based systems on acidic, infertile soils. ei]Section editor: G R Stewart

Nutrient stocks in managed and natural humid tropical fallows

Managed fallows which recover nutrients more rapidly than natural secondary vegetation may improve the performance of shifting agriculture systems operating under inadequately long fallow cycles. Our objective was to construct nutrient balances for the soil, vegetation, and litter compartments of six planted leguminous fallows and natural secondary vegetation during 53 months. The fallows were planted on a previously cultivated Ultisol (Acrisol) in the Peruvian Amazon and included:Centrosema macrocarpum (Centrosema),Pueraria phaseoloides (Pueraria),Stylosanthes guianensis (Stylosanthes),Desmodium ovalifolium (Desmodium),Cajanus cajan (Cajanus), andInga edulis (Inga). In addition, in the natural fallow treatment secondary vegetation was allowed to establish and grow naturally. Quantities of extractable P, K, Ca, and Mg, total N, and organic C in soil to a 45 cm depth, and macrouttrients in aboveground biomass, roots, and litter were estimated at fallow planting, at 8, 17, and 29 months afterward, and at fallow clearing (53 months). Total N stocks increased by 10% in the Stylosanthes, Desmodium, Pueraria, and Inga treatments, but changed little in the Cajanus, Centrosema and natural fallows. This difference was largely due to greater net increases in both soil and vegetation compartments in the former group of treatments. In the Inga, Desmodium, and natural fallows, total stocks of P and K at 53 months were about 40% to 80% greater and 12% greater, respectively, than initial values, but Ca and Mg stocks were reduced by 25% to 40%. In the other treatments, there was generally little change in P stocks, but large (30% to 60%) reductions in K, Ca, and Mg during the course of the fallow. Although there were net decreases of stocks of P, K, Ca, and Mg in soil in all treatments during the fallow, storage of P and K in vegetation and litter in the Inga, Desmodium, and natural fallows offset losses of these nutrients from soil. These treatments also tended to accumulate more Ca and Mg in biomass and litter than the other treatments. These results suggest that leguminous fallow vegetation that accumulates large amounts of biomass may increase N, P, and K stocks, but that incomplete recuperation of Ca and Mg may limit the sustainability of short-rotation fallow-based systems on acidic, infertile soils. ei]Section editor: G R Stewart

Nutrient concentration and acid–base status of leaf litter of tree species characteristic of the hardwood forest of southern Quebec

Leaf litter of 15 tree species characteristic of the deciduous and mixed forest of southern Quebec were analyzed for pH, directly titrable acids and bases in water extracts, ash bases, excess bases, excess ash bases, and for levels of N, P, K, Ca, and Mg. We hypothesized that many tree species typical of the climax of sugar maple (Acersaccharum Marsh.) dominated forest have leaf litter with a higher base status than sugar maple and red maple (Acerrubrum L.) leaf litter, and that the base status of leaf litter would be lower on wet sites. Mean differences among species were highly significant (p &lt; 0.0001) for all variables related to acidity or bases, but the effect of drainage was not. Red and sugar maple leaf litter was very acid and low in N concentration. American beech (Fagusgrandifolia Ehrh.) and red oak (Quercusrubra L.) leaf litter was not very acidic but was low in nutrient concentrations. White pine (Pinusstrobus L.) was lowest in all nutrients and ash bases but was low in titrable acidity. Directly titrable bases in leaf litter extracts were correlated positively with leaf litter N and Mg, and ash bases were positively correlated with leaf litter Ca and Mg. Many species typical of the sugar maple climax may have better soil ameliorating potential than sugar and red maple.

Effect of four multipurpose tree species on soil amelioration during tree fallow in Central Togo

The effects of Cassia siamea, Albizia lebbek, Acacia auriculiformis, and Azadirachta indica on soil fertility have been studied on five-year-old fallows on Ferric Acrisols in Central Togo. Litter quality and soil fertility under the four species were significantly different. Topsoil pH increases significantly with increasing litter Ca levels. Cassia siamea and Azadirachta indica were superior in enriching the sandy-loamy topsoils with Calcium and in increasing soil pH. Under Acacia, which had the highest biomass production, litter accumulation appeared to be responsible for the low mineral soil Ca and P values. In addition, topsoil pH under Acacia was lower than under grass or bush fallow or the other species. Slow litter mineralization of Acacia auriculiformis was probably caused by the thick, leathery consistence and high tannin content of its litter. Due to its high biomass production supporting soil acidification pure Acacia auriculiformis stands seemed to be less favourable for improving soil fertility on planted fallows but more suited for firewood plantations and topsoil protection. The foliage as well as the litter and topsoil under Albizia showed narrow C/N- and C/P-ratios resulting in easily mineralizable organic matter. All tree species tested were superior to natural grass/herb fallow in building up surface soil fertility. However, differences with natural bush fallow were not significant.

Organic matter and nutrients in the forest floor of a Pinus elliottii plantation and some effects of prescribed burning and superphosphate addition

The biomass and nutrient concentrations in the forest floor of a Pinus elliottii plantation in south-east Queensland, and some effects of prescribed burning (May 1981) and superphosphate application (September 1979) were measured on 14 occasions between August 1979 (age 14 years) and July 1984 (age 19 years). The biomass of the unburnt forest floor ranged from 12.9 t ha −1 (August 1979) to 20.1 t ha −1 (July 1981). Significant increases in the amounts of nitrogen (9.2 kg ha −1 year −1) and phosphorus (0.41 kg ha −1 year −1) were measured over the 5-year sampling period and were associated with significant increases in N and P concentrations. Calcium concentrations, in contrast, declined but no significant long-term trends in amounts of Ca or amounts and concentrations of potassium, sodium or magnesium were evident. Superphosphate approximately doubled the concentration and amount of P in the forest floor but had no apparent effect on biomass or other nutrients. The response was evident in the F1 and F2 layers and remained significant for the duration of the experiment. The single prescribed burn reduced the biomass of the forest floor by 8.2 t ha −1. This amounted to 52% of the biomass immediately before the fire and contained between 29% (P, fertilised treatment) and 66% (Na) of the reserves of each element in the forest floor. The biomass and amounts of N,K, Na and Mg were significantly lower in the burnt forest floor for 1.5–2.5 years following the fire but the differences steadily declined, and after 3 years no burning effects were evident. In contrast, P and Ca amounts did not differ significantly between treatments except for Ca on the first post-fire collection. Concentrations of Ca were significantly higher in the burnt forest floor for at least 1.5 years following the fire, suggesting that a significant proportion of the Ca in burnt litter was released slowly compared to other nutrients. The repeated loss of N (37 kg ha −1 in this study) due to periodic prescribed burning and also removal of N from the plantation in logs at the end of a rotation may lead to depletion of soil N reserves on a long-term basis.