Rates of litter decomposition over 6 years in Canadian forests: influence of litter quality and climate

2002 ◽  
Vol 32 (5) ◽  
pp. 789-804 ◽  
Author(s):  
J A Trofymow ◽  
T R Moore ◽  
B Titus ◽  
C Prescott ◽  
I Morrison ◽  
...  
Keyword(s):  
Litter Quality ◽  
Summer Precipitation ◽  
Winter Precipitation ◽  
Proximate Analysis ◽  
Resonance Spectroscopy ◽  
Mean Annual Temperature ◽  
Nutrient Contents ◽  
Natural Logarithm ◽  
Forest Sites ◽  
Exponential Decay Model

The effects of litter quality and climate on decomposition rates of plant tissues were examined using percent mass remaining (MR) data of 10 foliar litter types and 1 wood type during 6 years exposure at 18 upland forest sites across Canada. Litter-quality variables used included initial nutrient contents (N, P, S, K, Ca, Mg) and carbon fractions (determined by proximate analysis and 13C nuclear magnetic resonance spectroscopy). Climate variables used included mean annual temperature; total, summer, and winter precipitation; and potential evaptranspiration. A single-exponential decay model with intercept was fit using the natural logarithm of 0- to 6-year percent MR data (LNMR) for all 198 type by site combinations. Model fit was good for most sites and types (r2 = 0.64–0.98), although poorest for cold sites with low-quality materials. Multiple regression of model slope (Kf) and intercept (A) terms demonstrated the importance of temperature, summer precipitation, and the acid-unhydrolyzable residue to N ratio (AUR/N) (r2 = 0.65) for Kf, and winter precipitation and several litter-quality variables including AUR/N for A (r2 = 0.60). Comparison of observed versus predicted LNMR for the best overall combined models were good (r2 = 0.75–0.80), although showed some bias, likely because of other site- and type-specific factors as predictions using 198 equations accounted for more variance (r2 = 0.95) and showed no bias.

Variability in litter quality and its relationship to litter decay in Canadian forests

2000 ◽  
Vol 78 (10) ◽  
pp. 1269-1287 ◽  
Author(s):  
Caroline M Preston ◽  
JA (Tony) Trofymow ◽  
the Canadian Intersite Decompositio Working Group
Keyword(s):  
Mass Loss ◽  
Litter Decomposition ◽  
Litter Quality ◽  
Proximate Analysis ◽  
Resonance Spectroscopy ◽  
Magic Angle ◽  
Klason Lignin ◽  
Nmr Parameters ◽  
Organic Composition ◽  
Wide Range

Predicting the effects of climate change on litter decomposition requires an improved understanding of the link between organic composition and the parameters used to define litter quality. Carbon-13 nuclear magnetic resonance spectroscopy with cross-polarization and magic-angle spinning (CPMAS NMR) was used to characterize 36 foliar litters, including the species used in the Canadian Intersite Decomposition Experiment (CIDET), a Canada-wide long-term litter decomposition study. The litters showed a wide range of organic composition, qualitatively interpreted as the sum of component biopolymers (mainly carbohydrates, cutin, tannins, and lignin). Only weak correlations were found between NMR parameters and Klason lignin (KLIG); however, cluster analysis based on elemental, NMR, and proximate analysis gave good separation of botanical classes. NMR also had little predictive value for 3-year CIDET mass losses, which were negatively correlated with both KLIG and KLIG/N. Mass loss generally decreased in the following order: grass > pioneer broad-leafed deciduous > conifer (deciduous and evergreen) > American beech (a fagaceae) > wood. Predictive models for 3-year CIDET mass loss derived from linear regression with elemental, proximate, and NMR analyses were superior to those using only NMR parameters, with the best model based on KLIG, N, and Ca. Although providing no molecular-level understanding, KLIG integrates the most insoluble lignin, cutin, and tannin components. Limitations and possible improvements for NMR evaluation of litter quality are discussed.Key words: Klason lignin, 13C CPMAS NMR, proximate analysis, litter decomposition, tannin, cutin, CIDET.

13C nuclear magnetic resonance spectroscopy with cross-polarization and magic-angle spinning investigation of the proximate-analysis fractions used to assess litter quality in decomposition studies

1997 ◽  
Vol 75 (9) ◽  
pp. 1601-1613 ◽  
Author(s):  
Caroline M. Preston ◽  
J. A. (Tony) Trofymow ◽  
Junning Niu ◽  
Brian G. Sayer
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Litter Quality ◽  
Proximate Analysis ◽  
Magic Angle Spinning ◽  
Resonance Spectroscopy ◽  
Magic Angle ◽  
Klason Lignin ◽  
13C Nuclear Magnetic Resonance ◽  
Nuclear Magnetic

Proximate analysis is often used in decomposition studies to characterize the organic components of foliar litter. The percent weight residue remaining after extraction by nonpolar and polar solvents and H3SO4 hydrolysis (Klason lignin, KL) is commonly used as a measure of litter quality and a modelling parameter. While KL is associated with resistance to decay, its nature is not well understood and it has long been suspected that it incorporates nonlignin components. We used solid-state 13C nuclear magnetic resonance (NMR) spectroscopy to characterize litter, extracted residue, and the KL fraction of five species. NMR shows that cutin and condensed tannin are both significant components of litter and its extraction residues, in addition to lignin and carbohydrate. Hydrolysis with H2SO4 removes carbohydrates and amino acids, leaving the KL fraction derived from cutin, tannin, and lignin. Tannin retention in KL was also demonstrated by a hydrolysis study of purified tannins and a brown-rot lignin, using both NMR and the proanthocyanidin assay for condensed tannins. Although the NMR results are qualitative at this stage, it is clear that KL has limited use as a parameter controlling litter decomposition, and that other biopolymers should not be ignored in conceptual models, chemical analysis, and experimental design. Key words: Klason lignin, 13C CPMAS NMR, proximate analysis, litter quality, decomposition, tannin.

scholarly journals Spatial Analysis of Seasonal Precipitation Using Various Interpolation Methods in the Euphrates Basin, Turkey

2021 ◽  
Author(s):  
Okan Mert Katipoğlu
Keyword(s):  
Spatial Distribution ◽  
Geographical Information Systems ◽  
Polynomial Interpolation ◽  
Estimation Method ◽  
Summer Precipitation ◽  
Winter Precipitation ◽  
Geographical Information ◽  
Seasonal Precipitation ◽  
Interpolation Methods

Abstract It is vital to accurately map the spatial distribution of precipitation, which is widely used in many fields such as hydrology, climatology, meteorology, ecology, and agriculture. In this study, it was aimed to reveal the spatial distribution of seasonal long-term average precipitation in the Euphrates Basin by using various interpolation methods. For this reason, Simple Kriging (SK), Ordinary Kriging (OK), Universal Kriging (UK), Ordinary CoKriging (OCK), Empirical Bayesian Kriging (EBK), Radial Basis Functions (Completely Regularized Spline (CRS), Thin Plate Spline (TPS), Multiquadratic, Inverse Multiquadratic (IM), Spline with Tensor (ST)), Local Polynomial Interpolation (LPI), Global Polynomial Interpolation (GPI), Inverse Distance Weighting (IDW) methods have been applied in the Geographical Information Systems (GIS) environment. Long-term seasonal precipitation averages between 1966 and 2017 are presented as input for the prediction of precipitation maps. The accuracy of the precipitation prediction maps created was based on root mean square error (RMSE) values obtained from the cross-validation tests. The method of precipitation by interpolation yielding the lowest RMSE was selected as the most appropriate method. As a result of the study, OCK in spring and winter precipitation, LPI in summer precipitation, and OK in autumn precipitation were determined as the most appropriate estimation method.

scholarly journals Precipitation Variations under a Changing Climate from 1961–2015 in the Source Region of the Indus River

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1366
Author(s):  
Muhammad Rizwan ◽  
Xin Li ◽  
Kashif Jamal ◽  
Yingying Chen ◽  
Junaid Nawaz Chauhdary ◽  
...  
Keyword(s):  
Daily Precipitation ◽  
Source Region ◽  
Summer Precipitation ◽  
Heavy Precipitation ◽  
Winter Precipitation ◽  
Indus Basin ◽  
Indus River ◽  
Precipitation Characteristics ◽  
Daily Precipitation Data ◽  
Increasing Trends

The source region of the Indus River (SRIR), which is located in the Hindukush, Karakoram and Himalayan (HKH) mountainous range and on the Third Pole (TP), is very sensitive to climate change, especially precipitation changes, because of its multifarious orography and fragile ecosystem. Climate changes in the SRIR also have important impacts on social and economic development, as well as on the ecosystems of the downstream irrigation areas in Pakistan. This paper investigates the changes in precipitation characteristics by dividing the daily precipitation rate into different classes, such as light (0–10 mm), moderate (10.1–25 mm) and heavy precipitation (>25 mm). Daily precipitation data from gauging and non-gauging stations from 1961–2015 are used. The results of the analysis of the annual precipitation and rainy day trends show significant (p < 0.05) increases and decreases, respectively, while light and heavy precipitation show significant decreasing and increasing trends, respectively. The analysis of the precipitation characteristics shows that light precipitation has the highest number of rainy days compared to moderate or heavy precipitation. The analysis of the seasonal precipitation trends shows that only 18 stations have significant increasing trends in winter precipitation, while 27 stations have significant increasing trends in summer precipitation. Both short and long droughts exhibit increasing trends, which indicates that the Indus Basin will suffer from water shortages for agriculture. The results of this study could help policymakers cope with floods and droughts and sustain eco-environmental resources in the study area.

scholarly journals Spatial and seasonal patterns of precipitation in Greece: the terrain segmentation approach

2014 ◽  
Vol 16 (5) ◽  
pp. 988-997 ◽  
Keyword(s):  
Agricultural Land ◽  
Summer Precipitation ◽  
Winter Precipitation ◽  
Winter Period ◽  
Monthly Precipitation ◽  
Northern Greece ◽  
Agricultural Planning ◽  
Spatial And Seasonal Variation ◽  
Segmentation Approach ◽  
Spatio Temporal

<div> <p>The aim of the study is to investigate the spatial and seasonal variation of precipitation in Greece using multi-temporal data analysis techniques. Mean monthly precipitation grids of 1 km<sup>2</sup> resolution of the period 1950-2000 were used in the analysis. Cross correlation quantified spatio-temporal patterns which are summarized as follows a) the absolute correlations of precipitation versus elevation and longitude are minimized during the winter period, b) the latitude dependency of precipitation presents a seasonal shift where winter precipitation tends to be higher in northern Greece, while summer precipitation tends to be higher in southern Greece. Principal components analysis indicated that the first two components account for the 92.8% of variance in the spatio-temporal variability of precipitation in Greece. Cluster analysis segmented the terrain to 27 regions with distinct seasonal variability of precipitation. The majority of irrigated agricultural land (plains of Macedonia, Thessaly and Thrace) belong to clusters which present the lowest values of annual precipitation (&lt;600 mm year<sup>-1</sup>). The derivation of precipitation signatures for each region of Greece using the proposed terrain segmentation approach can support environmental decision and agricultural planning at a regional (country) scale in relation to water resources management.&nbsp;</p> </div> <p>&nbsp;</p>

scholarly journals The Paleoecological Record of 6 ka BP Climate in the Canadian Prairie Provinces

2007 ◽  
Vol 49 (1) ◽  
pp. 81-98 ◽  
Author(s):  
Robert E. Vance ◽  
Alwynne B. Beaudoin ◽  
Brian H. Luckman
Keyword(s):  
Boreal Forest ◽  
Forest Fires ◽  
Pinus Banksiana ◽  
Summer Precipitation ◽  
Circulation Pattern ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Canadian Prairie ◽  
Temperature And Precipitation ◽  
Prairie Provinces

ABSTRACTSynthesis of available paleoecological studies in the Prairie provinces of Canada indicates that although the peak in postglacial aridity that characterized early Holocene climate of the western foothills and plains had passed, conditions remained warmer and drier than present throughout the region ca. 6000 yr BP Compared to today, treeline elevations were higher and alpine glaciers were reduced in size in the Rocky Mountains, lake levels were lower over much of the Interior Plains, and the grassland and boreal forest ecozones extended north of their present positions. Forest fires were more prevalent ca. 6000 yr BP than they are today, aiding westward migration of jack pine (Pinus banksiana) through the boreal forest and increasing the area occupied by grassland in boreal and montane forest regions. Attempts to quantify the magnitude of 6 ka temperature and precipitation differences have produced variable results, but suggest that mean annual temperature was 0.50°C to 1.50°C higher than today (summer temperature may have been up to 3°C higher) and mean annual precipitation was reduced by 65 mm (or summer precipitation was reduced by 50 mm), compared to present. The nature and scale of these changes suggests that a vigorous zonal atmospheric circulation pattern, similar to that of the 1930s but shifted northward, prevailed at 6 ka.

scholarly journals Holocene Hydroclimate in the Southeastern United States During Abrupt Climate Events: Evidence From New Speleothem Isotopic Records From Alabama

2021 ◽  
Author(s):  
Martin Medina-Elizalde ◽  
Stefan Perritano ◽  
Matthew DeCesare ◽  
Josué Polanco-Martinez ◽  
Gabriela Serrato-Marks ◽  
...  
Keyword(s):  
United States ◽  
Model Simulation ◽  
Southeastern United States ◽  
Precipitation Amount ◽  
Summer Precipitation ◽  
Winter Precipitation ◽  
Meridional Overturning Circulation ◽  
Ice Age ◽  
Annual Rainfall ◽  
Spring Precipitation

Abstract We present new high-resolution absolute-dated stalagmite δ18O and δ13C records from the southeastern United States (SE US) spanning the last 12 thousand years (ka). A local relationship between annual rainfall amount and its amount-weighed δ18O composition exists on interannual timescales, driven mostly by an amount effect during summer and spring seasons, and by an isotopically depleted composition of fall and winter precipitation. Based on a novel interpretation of modern rainfall isotopic data, stalagmite δ18O variability is interpreted to reflect the relative contribution of summer and spring precipitation combined relative to combined fall and winter precipitation. Precipitation amount in the SE US increases during the Younger Dryas, the 8.2 ka and Little Ice Age abrupt cooling events. High precipitation during these events reflects enhancement of spring and summer precipitation while the contribution of fall and winter rainfall remained unchanged or decreased slightly. Results from this study support model simulation results that suggest increased precipitation in the SE US during Atlantic Meridional Overturning Circulation (AMOC) slowdown/shutdown (LeGrande et al., 2006; Renssen et al., 2002; Vellinga and Wood, 2002). In association with Northern Hemisphere mid-latitude cooling from the Early to mid-Holocene, annual precipitation in the SE US decreases, a pattern distinctive from that observed during abrupt cooling events related to AMOC shifts. Long-term hydroclimate change in the SE US is likely sensitive to summer insolation reduction as inferred for other tropical and subtropical regions. This study has implications for our understanding of the sensitivity of subtropical hydroclimate to factors both internal and external to the climate system in a warmer climate.

scholarly journals Bioconversion of Sawdust and Paper Treaded with Edible Fungus (Pleurotus pulmonarius)

2019 ◽  
pp. 1-7
Author(s):  
Jesupemi Mercy Enibukun ◽  
Sunday Ademola Laba
Keyword(s):  
Extracellular Enzymes ◽  
Sugar Content ◽  
Soluble Sugar ◽  
Proximate Analysis ◽  
Crude Fibre ◽  
Pleurotus Pulmonarius ◽  
Nutrient Contents ◽  
Paper Waste ◽  
Edible Fungus ◽  
Fiber Fractions

The aim of this study was to determine the effect of Pleurotus pulmonarius on proximate composition and solid-state fermentation of sawdust and waste paper, and to quantify the soluble sugar produced in the biodegraded samples. Studies were carried out on the biodegradation of sawdust and paper using P. pulmonarius in cultures incubated for 90 days. The results of proximate analysis showed decrease in moisture content crude fiber and hemicellulose, while ash and cellulose were increased. Sawdust has higher soluble sugar content at 30-90 days of fermentation. The crude fibre decreased significantly from 45.5% to 32.4%, 48.2% to 32.9%, 55.5% to 32.8%, 53.4 to 32.1%, 44.5% to 27.5% for sawdust (SD), paper-waste (PW), and three proportional ratio mixtures (PW1:SD3, PW3:SD1, PW1:SD1) substrates respectively. The nutrient contents, pH values, (%) fiber fractions showed significant differences of (P≤0.05) in the five substrates as the fermentation. Lignin contents of treated paper waste and sawdust were degraded by P. pulmonarius and a decrease was observed. There were also consistent significant decreases (P< 0.05) in the values obtained for NDF, ADF, ADL. Percentage NDF 75.4% to 57.32%, 68.1% to 57.05%, 67.21% to 56.8%, 75.49% to 58.36%, 74.3% to 59.13% for SD, PW, PW1:SD3, PW3:SD1, and PW1:SD1 substrates, respectively. Significant differences were observed in the hemicellulose and cellulose contents. The results obtained from the bioconversion process of selected wastes reveals the potential of extracellular enzymes produced by P. pulmonarius as a biotechnological tool for the transformation of waste in biological product.

scholarly journals Projected Hydroclimatic Changes in Two Major River Basins at the Canadian West Coast Based on High-Resolution Regional Climate Simulations

2017 ◽  
Vol 30 (20) ◽  
pp. 8081-8105 ◽  
Author(s):  
Andre R. Erler ◽  
W. Richard Peltier
Keyword(s):  
Water Resources ◽  
Rocky Mountains ◽  
Regional Climate ◽  
Summer Precipitation ◽  
River Basins ◽  
Winter Precipitation ◽  
Climate Projections ◽  
Drought Risk ◽  
Spring Freshet ◽  
The Impact

Abstract The impact of anthropogenic climate change on water resources and flood and drought risk is of great interest for impact modeling and to inform adaptation strategies. Here an analysis of hydroclimatic changes in the Fraser and Athabasca River basins in western Canada is presented, based on an ensemble of climate projections, which have been dynamically downscaled to 10-km resolution using the Weather Research and Forecasting Model in two configurations. The GCM ensemble comprises four independent integrations of the Community Earth System Model under the representative concentration pathway 8.5. Basin-integrated changes in the seasonal cycle of hydroclimatic variables, and the variability of water supply and flood and drought risk, are considered. It is found that fall and winter precipitation generally increase by 20%–30% toward the end of the century, while changes in summer precipitation are smaller and associated with high model uncertainty. Furthermore, a reduction in snowfall and an increase in evapotranspiration are projected. However, projected impacts on water resources east and west of the Rocky Mountains are quite different: in basins closer to the coast (west of the Rocky Mountains) higher temperatures lead to a transition from predominantly solid to liquid precipitation and a significantly weaker spring freshet, followed by drier summers. In the lee of the Rocky Mountains the spring freshet remains largely unaffected and in summer the increase in evapotranspiration (ET) is compensated by increasing precipitation, so that water balance changes appear to be small. It is further found that a shift in runoff seasonality near the coast may lead to significantly increased flood risk in fall.

IRRIGATION SUBSURFACE RETURN FLOWS AND WATER USE IN LYSIMETERS CONTAINING APPLE TREES

1989 ◽  
Vol 69 (4) ◽  
pp. 769-778 ◽  
Author(s):  
D. S. STEVENSON
Keyword(s):  
Water Use ◽  
Summer Precipitation ◽  
Bare Soil ◽  
Winter Precipitation ◽  
Design Flow ◽  
Return Flow ◽  
Irrigation Season ◽  
Apple Trees ◽  
Flow Measurements ◽  
Return Flows

For 9 yr, subsurface return flow measurements from irrigated lysimeters containing "Macspur McIntosh" apple trees (Malus domestica Borkh.) on MM 111 rootstocks were collected. Water use with and without a grass cover crop was calculated as irrigation plus summer precipitation minus drainage. Drainages were consistently and significantly lower, and therefore water use higher, under grass than under bare soil but the differences were not large. The times of irrigation and drainage events were not closely linked. Drainage followed irrigation anywhere from a day to many days, stretching at times into weeks or months. By far the largest drainages, however, occurred during the irrigation season. Irrigation amounts provided most of the water for return flows with summer or winter precipitation contributing little to the drainage. At the higher irrigation levels the return flow quantities and calculated water use quantities clearly indicate that sprinkler design flow quantities are too high for the area and that improvements in irrigation efficiencies are possible. Key words: Drainage, irrigation, lysimeters, water use, apple trees

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