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With escalating fertilizer prices, interest in using poultry litter as a source of plant nutrients has increased. However, the rapid decomposition of litter, particularly in the hot and humid southern United States, makes poultry litter vulnerable to loss of nutrients. Biochar and lignite have been proposed to mitigate nutrient loss, particularly N. However, information on the integration of biochar and lignite with poultry litter on cotton (Gossypium hirsutum L.) growth and yield is limited under southeastern agro‐ecosystems. A field experiment was conducted on a Leeper silty clay loam soil from 2017 to 2020 to evaluate the combined effect of poultry litter and inorganic N fertilizer with biochar and lignite on cotton growth, yield, and nutrient utilization. The treatments consisted of a 3 × 3 full‐factorial arrangement of amendments and fertilization types organized in a randomized complete block design. Application rates were 6.7 Mg ha–1 for poultry litter, 6.7 Mg ha–1 for biochar and lignite, and 134 kg N ha–1 for inorganic fertilizer. Lignite and biochar were only added once. The combination of biochar and lignite with poultry litter and inorganic fertilizer was positively effective on yield and yield components. Integration of biochar with poultry litter and inorganic fertilizer increased lint yield by 42 and 44% as compared with fertilization alone. Cotton leaf area index increased by 34 and 51% when biochar and lignite were combined with inorganic fertilizer in 2020. The leaching loss of postharvest soil NO3–N was significantly reduced by 66 and 50% when biochar and lignite were combined with inorganic fertilizer, respectively. Core Ideas: Combined biochar and lignite with poultry litter increased cotton yield.Integration of biochar and lignite with fertilization reduced NO3–N leaching loss.Poultry litter and inorganic fertilizer produced similar lint yield. [ABSTRACT FROM AUTHOR]

Plant litter can alter ecosystems and promote plant invasions by altering resource availability, depositing phytotoxins, and transmitting microorganisms to living plants. Transmission of microorganisms from invasive plant litter to live plants may gain importance as invasive plants, which often escape pathogens upon introduction to a new range, acquire new pathogens over time. It is unclear, however, if invasive plant litter affects native plant communities by promoting disease. Microstegium vimineum is an invasive grass that suppresses native populations, in part through litter production, and has acquired new fungal leaf spot diseases since its introduction to the United States. In a greenhouse experiment, we evaluated how M. vimineum litter and its pathogens mediated competition with the native grass Elymus virginicus. M. vimineum litter promoted disease on E. virginicus and suppressed establishment and biomass of both species. Litter had stronger negative effects on E. virginicus than M. vimineum, increasing the relative biomass of M. vimineum. Live plant competition reduced biomass of both species and live M. vimineum increased disease incidence on E. virginicus. Altogether, invasive grass litter suppressed both species, ultimately favoring the invasive species in competition, and increased disease incidence on the native species. [ABSTRACT FROM AUTHOR]

The amounts and ecological importance of epiphytic litterfall has often been overlooked in forest ecosystem studies. However, epiphytes participate in whole-ecosystem dynamics by capturing and retaining nutrients from atmospheric sources and transferring these nutrients to other ecosystem components. We quantified epiphytic litterfall under the canopy of mature bigleaf maples ( Acer macrophyllum Pursh) and compared it with other litter components in an old-growth temperate rainforest in Washington State. Total litterfall during one year was 4760 kg·ha−1, with the greatest contribution from bigleaf maple leaves. Of the total litter input, 546 kg·ha−1 consisted of epiphytic litter, equivalent to 12% of total fine litter input, the highest contribution of epiphyte litterfall documented for this type of forest. Compared with other studies in the Pacific Northwest, our estimations of conifer needle inputs relate to the location of the littertraps. Bigleaf maple leaves dominated carbon (C) and nitrogen (N) returns in litter; epiphytic litterfall contributed 240 kg·ha−1·year−1 of C (∼11% of total C inputs) and 5.7 kg·ha−1·year−1 of N (∼11% of total N inputs) to the forest floor. Inputs of N from epiphytes and bigleaf maple litter under the canopy of this tree could be important in augmenting N in this old-growth ecosystem. [ABSTRACT FROM AUTHOR]

The ability to predict fuel consumption during fires is essential for a wide range of applications, including estimation of fire effects and fire emissions. This project identified predictors of fuel consumption for the dominant fuel bed components (litter (<0.6-cm diameter dead material) and live herbs) during 217 prescribed fires in native longleaf pine ( Pinus palustris Mill.) and old-field loblolly pine ( Pinus taeda L.) - shortleaf pine ( Pinus echinata Mill.) communities in the southeastern United States. Additionally, these data were used to validate the First Order Fire Effects Model (FOFEM) fuel consumption computer model using custom and default fuel loads. Regression models using empirical data suggested that litter and live herb fuel consumption can be predicted by prefire litter and live herb fuel loads, litter and live herb fuel moisture, litter fuel bed bulk density, season of burn, years since fire, days since last rain ≥0.64 cm, relative humidity, energy release component, community type, pine and hardwood basal areas, and the Keetch-Byram drought index. FOFEM's prediction of fuel consumption for litter, live herbs, and duff combined using default fuel loads was 1.5 times the measured fuel consumption (where duff fuel load was zero). Refinement of FOFEM's fuel load and consumption calculations in the studied community types using the newly collected data and suggestions for model improvement would provide more accurate air quality inventories and assist in guiding appropriate regulation of prescribed fire. [ABSTRACT FROM AUTHOR]

The article presents a study which aims to characterize the amount of sugars, lignins and other components of leaf litter which can be used in ethanol production in the U.S. The study grounded leaves collected in the fall of 2007 which were then treated with sulfuric acid, were incubated, autoclaved and residual solid were then collected. The samples were analyzed by high performance liquid chromatography (HPLC). The study shows that the leaf litter was made up largely of lignins while cellulose, arabinan and xylan were found only in small quantities. Based on the findings the study concludes that fall leaf litter can yield approximately 60 gallons of ethanol per ton of leaves.

Litterfall and its subsequent decomposition are important feedback mechanisms in the intrasystem cycling of nutrients in forest ecosystems. The amount of litterfall and the rate of decomposition are expected to vary with stand age and climate. Over a 2-year period, decomposition of five litter types were measured in two second-growth forest stands and one old-growth stand in the Cascade Mountains of southern Washington state, USA. Both second-growth stands were dominated by Douglas-fir [ Pseudotsuga menziesii (Mirb.,) Franco] but one had a significant proportion of red alder ( Alnus rubra Bong.), a nitrogen (N) fixer. The old-growth stand was dominated by Douglas-fir and western hemlock [ Tsuga heterophylla (Raf.) Sarg.]. All stands had a relatively shallow layer of forest floor mass. The five litter types were placed in each stand to evaluate decomposition patterns. Despite significant differences in stand age, microclimate and mean residence times for carbon (C) and N, the rates of litter mass loss varied only slightly between sites. The relative order of species litter mass loss was: vine maple ≫ salal = western hemlock > Douglas-fir (from the youngest stand) > Douglas-fir (from the N rich stand with red alder). The initial litter lignin concentration, not lignin:N, was the primary determinant of decomposition rates, although the initial N concentration was the predictor for mass loss after 2 years in the N rich Douglas-fir-alder stand. All litter types showed immobilization of N for nearly 2 years. Data for Douglas-fir litter suggest that higher levels of N may retard decomposition of tissues with greater amounts of lignified material. The retention of N by the litter appeared influenced by the nutrient capital of the stands as well as the forest floor C:N ratio. Decomposition was minimal during the cold winter months, but displayed a definitive peak period during early Fall with wet weather, warm soils, and fungal activity. Thus, long-term climatic change effects on forest floor C storage may depend more on changes in seasonality of precipitation changes than just temperature changes. [ABSTRACT FROM AUTHOR]

Litterfall and fine root production were measured for three years as part of a carbon balance study of three forest stands in the Pacific Northwest of the United States. A young second-growth Douglas-fir [ Pseudotsuga menziesii (Mirb.) Franco] stand, a second-growth Douglas-fir with red alder ( Alnus rubra Bong.) stand, and an old-growth (∼550 years) Douglas-fir stand were monitored for inputs of carbon and nitrogen into the soil from litterfall and fine root production, as well as changes in soil C and N. Fine root production and soil nutrient changes were measured through the use of soil ingrowth bags containing homogenized soil from the respective stands. Litterfall biomass was greatest in the Douglas-fir-alder stand (527 g m−2 yr−1) that annually returned nearly three times the amount of N as the other stands. Mean residence time for forest floor material was also shortest at this site averaging 4.6 years and 5.5 years for C an N, respectively. Fine root production in the upper 20 cm ranged from 584 g m−2 in the N rich Douglas-fir-alder stand to 836 g m−2 in the old-growth stand. Fine root production (down to one meter) was always greater than litterfall with a below:above ratio ranging from 3.73 for the young Douglas-fir stand to 1.62 for the Douglas-fir-alder stand. The below:above N ratios for all three stands closely approximate those for biomass. Soil changes in both C and N differed by site, but the soil C changes in the old-growth stand mirrored those obtained in an ongoing CO2 flux study. Results from the soil ingrowth bags strongly suggest that this method provides a simple, but sufficient device for measuring potential fine root biomass production as well as soil chemical changes. [ABSTRACT FROM AUTHOR]

The temperate deciduous forest of the northeastern United States is believed to be undergoing a shift from domination by mixed oak (Quercus sp.) to red maple (Acer rubrum); a shift termed "The Red Maple Paradox." This shift in the composition of the forest has the potential to affect ecosystems within the forest that use leaf litter as an energy source. To assess the impact of the red maple paradox on detrital food webs, we conducted a mesocosm experiment investigating the influence of red maple litter on the food web of temporary woodland ponds. Amphibian biomass and survival were significantly lower in experimental ponds that contained only maple litter. The negative effects of maple litter were most pronounced in larval wood frogs (Rana sylvatica). We hypothesize that this effect resulted from a temporary shift from a grazing-based food web in oak mesocosms to a microbial-based food web in maple mesocosms, as oak mesocosms initially had higher levels of phytoplankton biomass and lower levels of bacterial production than maple mesocosms. This bottom-up effect of maple litter on wood frogs then appeared to affect other amphibians and zooplankton through a complex series of interactions. These data suggest that litter composition impacted the performance of most trophic groups by altering the processing of energy in this system, thereby destabilizing species interactions throughout the food web. Therefore, "subtle" compositional shifts in the forest have the potential to influence communities that rely upon leaf litter inputs as a primary source of energy. [ABSTRACT FROM AUTHOR]

We examined the relationship between phosphorus (P) uptake length (S[subw]) measured by stable PO[sub4] additions and the level of PO[sub4] enrichment from the additions during summer and fall in a first order stream in the southwestern portion of the Ozark Plateaus in northeast Oklahoma, USA. The y-intercept of this relation was used to more closely approximate ambient S[subw] and other metrics of P retention efficiency during summer and fall and determine the effect of leaf litter input on P retention efficiency and hydrological properties. Under similar discharge, the presence of the leaf litter during fall decreased water velocity and the dispersion coefficient, while the transient storage area increased compared to summer. An increase in S[subw] was generally observed with an increase in the level of P enrichment, and the linear relation (y-intercept) estimated S[subw] at 117 and 86 m during summer and fall. The slope of the linear relation was variable because a 5 µg L[sup-1] increase in P enrichment resulted in a 27 and 5 m increase in S[subw] estimation during summer and fall. Overall, the input of leaf litter into the stream had a relatively small effect on S[subw], but our results suggest P retention was slightly greater during fall compared to summer. [ABSTRACT FROM AUTHOR]

Litter is likely a critical resource for organisms inhabiting ephemeral aquatic habitats. Litter decomposition in temporary aquatic environments was experimentally studied. The authors used litterbags under different conditions of submergence and water physical and chemical properties/characteristics to study mass and nutrient losses of terrestrial materials in an ephemeral karst lake in Kentucky, U.S. Results indicate that litter decomposition dynamics in this temporary lake can be greatly affected by lake hydrology. Year-to-year variations in hydrology may thus have strong impacts on nutrient and energy release within this system, which may affect the organisms within this karst lake and in other areas of the karst ecosystem.

Examines the changes in forest litter production and nutrient cycling in a pine-hardwood forest during period of free-air carbon dioxide enrichment in the United States. Increase of total aboveground litterfall; Rise of nitrogen and phosphorus flux to the forest floor.

Summary:1. Standing dead plant litter of emergent macrophytes frequently constitutes a significant fraction of the detrital mass in many freshwater wetland and littoral habitats. Rates of leaf senescence and decomposition of the emergent macrophyte Juncus effusus were examined in a small freshwater wetland in central Alabama, U.S.A. Juncus effusus leaves in the initial stages of senescence were tagged in random plant tussocks and monitored periodically to determine in situ rates of leaf senescence and death. Fully senescent leaves were collected, placed in litter bags, and suspended above the sediments to simulate standing dead decay conditions. Litter bags were periodically retrieved over 2 years and analysed for weight loss, litter nutrient contents (N, P), associated fungal biomass and fungal taxa. 2. Senescence and death of J. effusus leaves proceeds from the leaf tip to the base at an exponential rate. The rate of senescence and death of leaf tissue increased with increasing temperatures. Plant litter decomposition was slow (k = 0.40 yr[sup –1]), with 49% weight loss observed in 2 years. Both the nitrogen (N) and phosphorus (P) concentration (%) of litter increased during decomposition. However, the total amount of nitrogen (mg) in litter bags remained stable and phosphorus increased slightly during the study period. 3. Fungal biomass associated with plant litter, as measured by ergosterol concentrations, varied between 3 and 8% of the total detrital weight. Values were not significantly different among sampling dates (P > 0.05, ANOVA, Tukey). Fungi frequently identified on decaying litter were Drechslera sp., Conioscypha lignicola (Hyphomycetes), Phoma spp. (Coelomycetes), Panellus copelandii and Marasmiellus sp. (Basidiomycota). 4. These results support previous findings that plant litter of emergent macrophytes does not require submergence or collapse to the sediment surface to initiate microbial colonization and litter decomposition. [ABSTRACT FROM AUTHOR]

Examines the pattern of changes in above-ground plant litter with altitude in the White Mountains of New Hampshire. Physical changes along the altitudinal gradient; Influence of temperature and evapotranspiration on litterfall.

Investigates leaf litter redistribution in a hardwood forest in West Virginia. Observation of deposition, decomposition and movement of leaf litter; Significance of downslope leaf movement; Influence of fallen logs and microtopographic depressions; Patterns of leaf deposition and leaf decomposition; Concentrations of soil organic matter and soil nutrients.