Heterogeneity of decomposition and nutrient dynamics of oak (Quercus) logs during the first 2 years of decomposition

1992 ◽  
Vol 22 (2) ◽  
pp. 161-166 ◽  
Author(s):  
T.D. Schowalter
Keyword(s):  
North Carolina ◽  
Decay Rate ◽  
Nutrient Dynamics ◽  
Early Stage ◽  
Initial Period ◽  
Nutrient Release ◽  
Nutrient Content ◽  
Decomposition Rates ◽  
Inner Bark ◽  
Lag Times

Decomposition of oak (Quercus spp.) logs (25–35 cm diameter, 3 m long) was compared among log substrates in Oregon, Minnesota, Kansas, and North Carolina during the first 2 years on the ground. Decomposition rates (k) for integrated logs averaged 0.28 ± 0.04 year−1 (mean ± 1 SD)) during this initial period. Decomposition reflected qualitative differences among log substrates (outer and inner bark, sapwood and heartwood). Inner bark had the highest nutritional quality and was the focus of insect and microbial activity during this early stage of decomposition; only 20% of initial mass remained after 2 years (k = 0.59 ± 0.15 year−1). Sapwood decayed more slowly than heartwood, with an overall decay rate of 0.20 ± 0.15 year−1). Heartwood lost 50% of its mass during the 1st year, but showed no further loss during the 2nd year, for an overall decay rate of 0.31 ± 0.05 year−1. Nutrient content generally declined during decomposition, but P accumulated in heartwood and Na accumulated in sapwood and heartwood during the 2nd year. Results indicate that decomposition of whole logs integrates different decomposition rates and lag times (i.e., time prior to initiation of decomposition) among log substrates varying in qualitative factors. Multiple-exponential models may be necessary to predict rates and sources of carbon and nutrient release to the atmosphere and soil.

scholarly journals How nutrient rich are decaying cocoa pod husks? The kinetics of nutrient leaching

2021 ◽  
Author(s):  
D.-G. J. M. Hougni ◽  
A. G. T. Schut ◽  
L. S. Woittiez ◽  
B. Vanlauwe ◽  
K. E. Giller
Keyword(s):  
Nutrient Release ◽  
Nutrient Content ◽  
Nutrient Leaching ◽  
Intense Rainfall ◽  
Decomposition Rates ◽  
Rainfall Events ◽  
Rainfall Frequency ◽  
Water Saturated ◽  
Kinetics Of ◽  
Cocoa Pod Husks

Abstract Aim Recycling of cocoa pod husks has potential to contribute to mineral nutrition of cocoa. Yet little is known of the nutrient content and nutrient release patterns from the husks. The potassium (K) rich husks are usually left in heaps in cocoa plantations in Africa. We aimed to understand and quantify release patterns of K and other nutrients from husks under varying rainfall regimes and assessed the effects of partial decomposition and inundation on nutrient leaching rates. Methods We incubated chunks of cocoa pod husks to assess decomposition rates and we measured nutrient leaching rates from two sets of husk chunks: one set was placed in tubes that were submitted to simulated scheduled rainfall events while the second set was continuously inundated in beakers. Results Decomposition of husks followed a second-order exponential curve (k: 0.09 day−1; ageing constant: 0.43). Nutrient losses recorded within 25 days were larger and more variable for K (33%) than for other macronutrients released in this order: Mg > Ca ≈ P > N (less than 15%). Potassium leaching was mainly driven by rainfall frequency (P < 0.05) and reinforced by intense rainfall, especially at lower frequency. Under water-saturated conditions, 11% of K was leached out within 48 h from fresh husks compared with 92% from partially decayed husks. Conclusion Some initial decomposition of cocoa pod husks is required to expose K to intense leaching. As decomposition progresses, abundant K losses are to be expected under frequent and/or intense rainfall events.

scholarly journals Nutrient dynamics in decomposing litter from four selected tree species in Makurdi, Benue State, Nigeria

2019 ◽  
Vol 43 (1) ◽  
Author(s):  
Thomas Okoh ◽  
Esther Edu
Keyword(s):  
Exposure Time ◽  
Decomposition Rate ◽  
Nutrient Dynamics ◽  
Nutrient Release ◽  
Wet Season ◽  
Decomposition Rates ◽  
Average Mass ◽  
Accumulation Index ◽  
Carbon Retention ◽  
Vitex Doniana

Abstract Background Nutrient release during litter decomposition was investigated in Vitex doniana, Terminalia avecinioides, Sarcocephallus latifolius, and Parinari curatellifolius in Makurdi, Benue State Nigeria (January 10 to March 10 and from June 10 to August 10, 2016). Leaf decomposition was measured as loss in mass of litter over time using the decay model Wt/W0 = e−kd t, while $$ \mathrm{Kd}=-\frac{1}{t} In\left(\frac{Wt}{W0}\right) $$Kd=−1tInWtW0 was used to evaluate decomposition rate. Time taken for half of litter to decompose was measured using T50 = ln 2/k; while nutrient accumulation index was evaluated as NAI =$$ \left(\frac{\omega t\ Xt}{\omega \mathrm{o}X\mathrm{o}}\right). $$ωtXtωoXo. Results Average mass of litter remaining after exposure ranged from 96.15 g, (V. doniana) to 78.11 g, (S. lafolius) in dry (November to March) and wet (April to October) seasons. Decomposition rate was averagely faster in the wet season (0.0030) than in the dry season (0.0022) with P. curatellifolius (0.0028) and T. avecinioides (0.0039) having the fastest decomposition rates in dry and wet seasons. Mean residence time (days) ranged from 929 to 356, while the time (days) for half the original mass to decompose ranged from 622 to 201 (dry and wet seasons). ANOVA revealed highly significant differences (p < 0.01) in decomposition rates and exposure time (days) and a significant interaction (p < 0.05) between species and exposure time in both seasons. Conclusion Slow decomposition in the plant leaves implied carbon retention in the ecosystem and slow release of CO2 back to the atmosphere, while nitrogen was mineralized in both seasons. The plants therefore showed effectiveness in nutrient cycling and support productivity in the ecosystem.

Environmental policy and swine manure management Waste not or want not?

1995 ◽  
Vol 10 (4) ◽  
pp. 163-166 ◽  
Author(s):  
Dana L. Hoag ◽  
Fritz M. Roka
Keyword(s):  
North Carolina ◽  
Environmental Policy ◽  
Systems Approach ◽  
Swine Manure ◽  
Nutrient Content ◽  
Livestock Production ◽  
Economic Incentives ◽  
Land Application ◽  
Manure Management ◽  
Interactive Nature

AbstractLivestock production and manure handling decisions often have been treated in the literature as separate enterprises. Policymakers, too, have ignored the interactive nature of manure management by focusing on land application for nutrient disposal. This study outlines a systems approach to describe the interrelated decisions producers face, using examples from North Carolina and Iowa that show how producers' attitudes toward manure management lead them to handle manure differently in different regions. In North Carolina, nutrients in manure are “not wanted.” There are economic incentives to treat manure, thus reducing its nutrient content, and to apply it on as little land as possible. In Iowa, nutrients are “not wasted.” Producers conserve the nutrients in manure and use them more fully, applying manure to higher value crops such as corn. Policies that influence manure management can be made more effective by accounting for the differences in producers' incentives to waste or want the nutrients.

Microbial ecology of untreated and copper–chrome–arsenic treated stakes exposed in a tropical soil. 1. The initial invaders

1972 ◽  
Vol 18 (12) ◽  
pp. 1923-1931 ◽  
Author(s):  
H. Greaves
Keyword(s):  
Microbial Ecology ◽  
Early Stage ◽  
Initial Period ◽  
Trichoderma Viride ◽  
Untreated Wood ◽  
Soft Rot ◽  
Eucalyptus Regnans ◽  
Ground Treatment ◽  
Colonization Period ◽  
Copper Chrome Arsenic

A study of the microbial ecology of copper–chrome–arsenic treated and untreated Pinus radiata and Eucalyptus regnans sapwood ground stakes exposed for a total of [Formula: see text] years is currently being made. The results presented in this report cover the initial colonization period during the first 7 months of exposure. Soft rot in the outer layers of both species of untreated wood occurs after only 1 month in the ground. Treatment with CCA prevents the early attack of pine but is not as effective in the eucalypt, nor does it appear to have a significant effect upon the diversity of microorganisms which colonize the two woods. For the first 2 months Penicillia are the predominating members of the population. Trichoderma viride, Paecilomyces fumo-roseus, and Cladosporium spp. are also frequently isolated. At 4 months more active soft-rotting fungi can be isolated, e.g. Chaetomium globosum and Humicola grisea, together with Fusaria and Phycomycetes. Bacteria colonize the stakes at a very early stage, the population changing little over this initial period of the study. Actinomycetes were not isolated until the wood had been in the ground for a month or more after which their importance in the population has steadily increased. Basidiomycetes were microscopically observed in sections of the stakes but have not been isolated to date.

scholarly journals Lag Times as Indicators of Hydrological Mechanisms Responsible for NO3-N Flushing in a Forested Headwater Catchment

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1092
Author(s):  
Klaudija Sapač ◽  
Andrej Vidmar ◽  
Nejc Bezak ◽  
Simon Rusjan
Keyword(s):  
Soil Moisture ◽  
Linear Regression ◽  
Forest Soils ◽  
Nutrient Dynamics ◽  
Precipitation Amount ◽  
Lag Time ◽  
Nutrient Loss ◽  
Time Step ◽  
Lag Times ◽  
N Flux

Understanding the temporal variability of the nutrient transport from catchments is essential for planning nutrient loss reduction measures related to land use and climate change. Moreover, observations and analysis of nutrient dynamics in streams draining undisturbed catchments are known to represent a reference point by which human-influenced catchments can be compared. In this paper, temporal dynamics of nitrate-nitrogen (NO3-N) flux are investigated on an event basis by analysing observed lag times between data series. More specifically, we studied lag times between the centres of mass of six hydrological and biogeochemical variables, namely discharge, soil moisture at three depths, NO3-N flux, and the precipitation hyetograph centre of mass. Data obtained by high-frequency measurements (20 min time step) from 29 events were analysed. Linear regression and multiple linear regression (MLR) were used to identify relationships between lag times of the above-mentioned processes. We found that discharge lag time (LAGQ) and NO3-N flux lag time (LAGN) are highly correlated indicating similar temporal response to rainfall. Moreover, relatively high correlation between LAGN and soil moisture lag times was also detected. The MLR model showed that the most descriptive variable for both LAGN and LAGQ is amount of precipitation. For LAGN, the change of the soil moisture in the upper two layers was also significant, suggesting that the lag times indicate the primarily role of the forest soils as the main source of the NO3-N flux, whereas the precipitation amount and the runoff formation through the forest soils are the main controlling mechanisms.

Decomposition and nutrient release from green needles of western hemlock and Pacific silver fir in an old-growth temperate rain forest9 Olympic National Park, Washington

1995 ◽  
Vol 25 (7) ◽  
pp. 1049-1057 ◽  
Author(s):  
Robert L. Edmonds ◽  
Ted B. Thomas
Keyword(s):  
Mass Loss ◽  
National Park ◽  
Nutrient Dynamics ◽  
Western Hemlock ◽  
Dominant Factor ◽  
Silver Fir ◽  
Decomposition Rates ◽  
Old Growth ◽  
Olympic National Park ◽  
Significant Difference

Decomposition rates and nutrient dynamics (for N, P, K, Ca, Mg, Mn, and Na) were determined for green needles of western hemlock (Tsugaheterophylla (Raf.) Sarg.) and Pacific silver fir (Abiesamabilis (Dougl.) Forb.) in an old-growth forested watershed (58 ha West Twin Creek) in the Hoh River valley, Olympic National Park, Washington. The influence of temperature and substrate chemistry on decomposition was determined. Temperature was the dominant factor controlling decomposition rates in the first year in this watershed, with the fastest decomposition at an elevation of 275 m (lower watershed) and the slowest decomposition at 725 m (upper watershed). After 12 months mass loss averaged 36% in the lower watershed and 28% in the upper watershed. There was no significant difference in decomposition rates between species. Substrate chemistry, i.e., the lignin/N ratio, became a more important factor than temperature as decomposition proceeded. After 37 months mass loss for needles averaged 61% for western hemlock and 50% for Pacific silver fir, with no difference by watershed location. After 61 months both types of substrates appeared to be approaching similar substrate chemistry and similar decomposition rates and there were no significant differences by species or watershed location. Decomposition constants (k values) after 61 months were 0.26 and 0.20 year−1 for western hemlock needles in the lower and upper watershed, respectively, and 0.22 and 0.19 year−1 for Pacific silver fir needles in the lower and upper watershed, respectively. Nitrogen was immobilized during the first 12 months of decomposition in needles of both species and then released. No other elements were immobilized during the initial (0- to 12-month) decomposition period, except for Ca in Pacific silver fir needles. However, in the 37- to 61-month period there was a considerable immobilization of Mg and Na in both species in the upper and lower watershed and K and Mn in both species in the upper watershed.

Racial disparities in initiation of endocrine therapy for early-stage breast cancer.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 6572-6572
Author(s):  
Katherine Elizabeth Reeder-Hayes ◽  
Anne-Marie Meyer ◽  
Stacie Dusetzina ◽  
Huan Liu ◽  
Stephanie B. Wheeler
Keyword(s):  
Breast Cancer ◽  
North Carolina ◽  
Black Women ◽  
Endocrine Therapy ◽  
White Women ◽  
Early Stage ◽  
Breast Conserving Surgery ◽  
Cancer Information ◽  
Primary Therapy ◽  
The North

6572 Background: Oral endocrine therapy (ET) is the cornerstone of adjuvant therapy for hormone receptor-positive (HR+) breast cancer, greatly reducing the risk of recurrence and death when taken for at least 5 years. Failure to initiate ET is a known problem that adversely affects recurrence and survival. The survival gap between black and white women with breast cancer is most pronounced in HR+ subtypes, and could be related to differences in ET use. The relationship between race and failure to initiate ET is not well defined. We investigated patterns of ET initiation by race in a diverse cohort of women covered by commercial health insurance. Methods: We identified 2753 women with incident HR+ breast cancer in the North Carolina Central Cancer Registry whose records linked to insurance claims using the statewide Integrated Cancer Information and Surveillance System (ICISS) database maintained by the University of North Carolina. The sample included privately insured women age <65 years who were diagnosed with stage I-III HR+ breast cancer between 2004 and 2009 and received primary therapy including breast surgery within 12 months of diagnosis. We used multivariate Poisson regression with robust variance to examine the effect of race on likelihood of initiating ET (tamoxifen, anastrozole, letrozole or exemestane). Results: 14% of eligible women did not initiate any form of ET within 12 months of diagnosis. Black women initiated ET at a significantly lower rate (IRR 0.83, 95% CI 0.73-0.93) after adjustment for age, disease characteristics, other treatments, and socioeconomic variables. Women receiving breast conserving surgery (BCS) without radiation (RT) were less likely to initiate compared to those receiving BCS + RT or mastectomy, and women whose treatment included chemotherapy were less likely to initiate ET. Conclusions: Black women in our sample were significantly less likely to initiate ET in a timely fashion than their white counterparts. This underutilization may contribute to the pronounced survival gap among black women with HR+ breast cancer, and represents an opportunity for intervention to reduce breast cancer disparities. Further investigation is needed to understand the reasons why black women do not initiate ET.

scholarly journals Early stage litter decomposition rates for Swiss forests

2004 ◽  
Vol 70 (3) ◽  
pp. 299-313 ◽  
Author(s):  
Alexander Heim ◽  
Beat Frey
Keyword(s):  
Litter Decomposition ◽  
Early Stage ◽  
Decomposition Rates

scholarly journals Quantification of Litter Fall and Estimation of Nutrient Release Through in-Situ Decomposition of Leaf Litter From Some Important Mangrove Species of Indian Sundarbans

2021 ◽  
Author(s):  
S.K. Das ◽  
Ranjan Kumar Manna ◽  
Pranab Gogoi ◽  
Roshith C. M. ◽  
Sajina A. M. ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Leaf Litter ◽  
Nutrient Dynamics ◽  
Nutrient Release ◽  
Mangrove Ecosystem ◽  
Litter Fall ◽  
Mangrove Species ◽  
Indian Sundarbans ◽  
In Situ Experiments

Abstract Looking into the importance of mangrove leaf litter in regulation of sediment carbon sequestration and nutrient flux in Sundarbans ecosystem, an experiment was conducted at Jharkhali island of Sundarbans. In this experiment, collection of leaf litter-shedding from nine dominant mangrove species during December 2012 to November 2013 was donemonthly using ‘litter traps’ (1 m2) in Eco-garden on the bank of Herobhanga creek.Seasonal litter fall was highest in Geon (Excoecariaagallocha)(103 gm-2) followed by Keora (Sonneratiaapetala) (98.5 gm-2). Kal Bain (Avicennia alba) produced the highest amount (414.37 gm-2) of total annual leaf litter followed by Bruguieragymnorrhiza (410.43 gm-2). Kankra (Bruguieragymnorrhiza), Garjan (Rhizophoramucronata) and Geon (Excoecariaagallocha) dry leaf litters contained more than 50% carbon (oven dry basis). Litter from Avicennia group contained more nitrogen and carbon. Decomposition rates of various mangrove litters were estimated through twoshort-term (30 days and 52 days) in-situ experiments using mangrove leaf litter in nylon net bags (0.6 mm mesh) subjected to periodical diurnal submergence by tidalriver water at Jharkhali. During decomposition process,observation said thatmost susceptible and resistant litter with respect to mass loss were Geon (Excoecariaagallocha) (81±5.5%) and Taura (Aegialitisrotundifolia) (26±4%) respectivelyafter 30 days. The biomass retained after decomposition losses (average45±15.2%after 30 days and 56±20.2 % after 52 days) indicated the amount of carbon retained in mangrove soil and ultimately determines the carbon sequestered in soil through mangrove litter fall. The study gives important insight into contribution of different mangrove species in carbon sequestration and nutrient dynamics in mangrove ecosystem of Indian Sundarbans.

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