scholarly journals Effect of elevation, season and accelerated snowmelt on biogeochemical processes during isolated conifer needle litter decomposition

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11926
Author(s):  
Laura T. Leonard ◽  
Eoin L. Brodie ◽  
Kenneth H. Williams ◽  
Jonathan O. Sharp
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Microbial Ecology ◽  
Litter Decomposition ◽  
Soil Type ◽  
Elevation Gradient ◽  
Slope Aspect ◽  
Gas Flux ◽  
Needle Litter ◽  
Decomposition Processes

Increased drought and temperatures associated with climate change have implications for ecosystem stress with risk for enhanced carbon release in sensitive biomes. Litter decomposition is a key component of biogeochemical cycling in terrestrial ecosystems, but questions remain regarding the local response of decomposition processes to climate change. This is particularly complex in mountain ecosystems where the variable nature of the slope, aspect, soil type, and snowmelt dynamics play a role. Hence, the goal of this study was to determine the role of elevation, soil type, seasonal shifts in soil moisture, and snowmelt timing on litter decomposition processes. Experimental plots containing replicate deployments of harvested lodgepole and spruce needle litter alongside needle-free controls were established in open meadows at three elevations ranging from 2,800–3,500 m in Crested Butte, Colorado. Soil biogeochemistry variables including gas flux, porewater chemistry, and microbial ecology were monitored over three climatically variable years that shifted from high monsoon rains to drought. Results indicated that elevation and soil type influenced baseline soil biogeochemical indicators; however, needle mass loss and chemical composition were consistent across the 700 m elevation gradient. Rates of gas flux were analogously consistent across a 300 m elevation gradient. The additional variable of early snowmelt by 2–3 weeks had little impact on needle chemistry, microbial composition and gas flux; however, it did result in increased dissolved organic carbon in lodgepole porewater collections suggesting a potential for aqueous export. In contrast to elevation, needle presence and seasonal variability of soil moisture and temperature both played significant roles in soil carbon fluxes. During a pronounced period of lower moisture and higher temperatures, bacterial community diversity increased across elevation with new members supplanting more dominant taxa. Microbial ecological resilience was demonstrated with a return to pre-drought structure and abundance after snowmelt rewetting the following year. These results show similar decomposition processes across a 700 m elevation gradient and reveal the sensitivity but resilience of soil microbial ecology to low moisture conditions.

scholarly journals Carbon and Nitrogen Responses in Litterfall and Litter Decomposition in Red Pine (Pinus densiflora S. et Z.) Stands Disturbed by Pine Wilt Disease

Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 244 ◽  
Author(s):  
Choonsig Kim ◽  
Seongjun Kim ◽  
Gyeongwon Baek ◽  
A-Ram Yang
Keyword(s):  
Litter Decomposition ◽  
Pinus Densiflora ◽  
Pine Wilt Disease ◽  
Wilt Disease ◽  
Red Pine ◽  
Disturbance Intensity ◽  
Pine Wilt ◽  
Needle Litter ◽  
Decomposition Processes ◽  
C And N

Research Highlight: Forest disturbance by insects or disease can have a significant influence on nutrient return by litterfall and decomposition, but information regarding disturbance gradients is scarce. This study demonstrated that the disturbance intensity caused by pine wilt disease greatly altered the quality and quantity of carbon (C) and nitrogen (N) in litterfall components and decomposition processes. Background and Objectives: This study was conducted to evaluate the C and N status of litterfall and litter decomposition processes in a natural red pine (Pinus densiflora S. et Z.) stand disturbed by pine wilt disease in southern Korea. Nine red pine plots with varying degrees of disturbance caused by pine wilt disease were established based on differences in the stand basal area. Litterfall and the decomposition of needle litter and branches under different degrees of disturbance were measured for three years. Results: There was a significant correlation (p < 0.05) between disturbance intensity and the C and N concentration of litterfall components depending on the time of sampling. The annual C and N inputs through litterfall components decreased linearly with decreasing disturbance intensities. The decomposition rates of branches were higher in slightly disturbed plots compared with severely disturbed plots for the late stage of branch decomposition, whereas the decomposition rates of needle litter were not affected by the disturbance intensity of pine wilt disease. Carbon and N concentrations from needle litter and branches were not linearly related to the intensities of disturbance, except for the initial stage (one year) of needle litter decomposition. Conclusions: The results indicated that the incidence of pine wilt disease was a major cause of C and N loss through litterfall and decomposition processes in pine wilt disease disturbed stands, but the magnitude of loss depended on the severity of the disease disturbance.

scholarly journals The Impact of Climate Change on Betula tortuosa Ledeb. Radial Increment on the Eastern Macroslope of Kuznetsk Alatau

2019 ◽  
Vol 16 ◽  
pp. 00025
Author(s):  
Il’ya A. Petrov ◽  
Alexey S. Golyukov ◽  
Alexandr S. Shushpanov ◽  
Viacheslav Kharuk
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Root Zone ◽  
Elevation Gradient ◽  
Mountain Forest ◽  
Radial Increment ◽  
Climate Variables ◽  
Climatic Response ◽  
Birch Trees ◽  
The Impact

The climatic response of birch in eastern Kuznetzky Alatau Mountains (Siberia) were analysed based on dendrochronology data. Studied climate variables included temperature, precipitation and root zone moisture (RZM). Periods with maximal correlations for each variable were found. It was established that radial increment was limited by June temperature and July RZM. Correlations of radial increment and ecoclimatic factors were higher when a negative anomalies of respective factor occurred. To estimate the advancement rate of birch trees along elevation gradient, three elevational transects were laid in mountain forest-tundra ecotone. Estimated advancement rate is about 0.5 m per year. Although temperature have a stimulating effect on birch’s radial increment and advancement on elevation gradient in Kuznetzky Alatau Mountains, some depressions in radial increment corresponds to years with soil moisture decrease.

scholarly journals The influence of slope aspect on soil moisture

2020 ◽  
Vol 12 (1) ◽  
pp. 82-93
Author(s):  
Csaba Varga ◽  
Levente Csiszér
Keyword(s):  
Soil Moisture ◽  
Soil Type ◽  
Gravimetric Method ◽  
Moisture Distribution ◽  
Slope Aspect ◽  
Organic Carbon Content ◽  
Organic C ◽  
Weight Percentage ◽  
Water Holding ◽  
Soil Moisture Distribution

AbstractIn this research, we investigated the variability of soil moisture on two slopes of opposite aspect (a northern slope and a southern slope) but with the same soil type. To identify the spatial disposal of the soil type on both slopes, we georeferenced the paper-based soil map of Sfântu Gheorghe, using the QGIS platform. In order to use the correct slope aspect, we used a numerical model of the terrain (relief). The research plot was soil sampled at the depth of 10 cm on two different dates: on 7 November 2019 and on 3 March 2020, using a Buerkle soil sampler.Gravimetric method was used to determine the soil moisture values that proved to be the most accurate for our purpose.The soil moisture values, obtained in weight percentage, were assigned to the coordinates of the sampling points, and soil moisture maps were generated in QGIS for both slopes and for both sampling dates. These maps gave us the opportunity to evaluate the variability in time of the soil moisture distribution on the sample plots.The water holding capacity of the soils is mostly influenced by their organic C content. So, the total organic carbon content of the soil from the sampling plots was measured using the Tyurin method.

The legacy of climate change effects: previous drought increases short-term litter decomposition rates in a temperate mixed grass- and shrubland

2016 ◽  
Vol 408 (1-2) ◽  
pp. 183-193 ◽  
Author(s):  
Merian Skouw Haugwitz ◽  
Anders Michelsen ◽  
Anders Priemé
Keyword(s):  
Climate Change ◽  
Litter Decomposition ◽  
Decomposition Rates ◽  
Short Term ◽  
Climate Change Effects ◽  
Mixed Grass

scholarly journals Historical climate controls soil respiration responses to current soil moisture

2017 ◽  
Vol 114 (24) ◽  
pp. 6322-6327 ◽  
Author(s):  
Christine V. Hawkes ◽  
Bonnie G. Waring ◽  
Jennifer D. Rocca ◽  
Stephanie N. Kivlin
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Soil Respiration ◽  
Carbon Cycling ◽  
Large Scale ◽  
Microbial Respiration ◽  
Rainfall Gradient ◽  
Soil Microbial ◽  
Historical Climate ◽  
Moisture Dependence

Ecosystem carbon losses from soil microbial respiration are a key component of global carbon cycling, resulting in the transfer of 40–70 Pg carbon from soil to the atmosphere each year. Because these microbial processes can feed back to climate change, understanding respiration responses to environmental factors is necessary for improved projections. We focus on respiration responses to soil moisture, which remain unresolved in ecosystem models. A common assumption of large-scale models is that soil microorganisms respond to moisture in the same way, regardless of location or climate. Here, we show that soil respiration is constrained by historical climate. We find that historical rainfall controls both the moisture dependence and sensitivity of respiration. Moisture sensitivity, defined as the slope of respiration vs. moisture, increased fourfold across a 480-mm rainfall gradient, resulting in twofold greater carbon loss on average in historically wetter soils compared with historically drier soils. The respiration–moisture relationship was resistant to environmental change in field common gardens and field rainfall manipulations, supporting a persistent effect of historical climate on microbial respiration. Based on these results, predicting future carbon cycling with climate change will require an understanding of the spatial variation and temporal lags in microbial responses created by historical rainfall.

Bacterial community changes during fir needle litter decomposition in an alpine forest in eastern Tibetan Plateau

2016 ◽  
Vol 47 (2) ◽  
pp. 145-157
Author(s):  
Yeyi Zhao ◽  
Fuzhong Wu ◽  
Wanqin Yang ◽  
Wei He ◽  
Bo Tan ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Bacterial Community ◽  
Litter Decomposition ◽  
Eastern Tibetan Plateau ◽  
Alpine Forest ◽  
Needle Litter ◽  
Community Changes

Feedback interactions between needle litter decomposition and rhizosphere activity

Oecologia ◽  
2004 ◽  
Vol 139 (4) ◽  
pp. 551-559 ◽  
Author(s):  
Jens-Arne Subke ◽  
Volker Hahn ◽  
Giovanna Battipaglia ◽  
Sune Linder ◽  
Nina Buchmann ◽  
...  
Keyword(s):  
Litter Decomposition ◽  
Needle Litter

Soil Type Modifies the Impacts of Warming and Snow Exclusion on Carbon and Nutrient Losses

2021 ◽  
Author(s):  
Stephanie M. Juice ◽  
Paul G. Schaberg ◽  
Alexandra M. Kosiba ◽  
Carl E. Waite ◽  
Gary J. Hawley ◽  
...  
Keyword(s):  
Climate Change ◽  
Nutrient Cycling ◽  
Soil Type ◽  
Soil Characteristics ◽  
Nutrient Loss ◽  
Climate Projections ◽  
Nutrient Losses ◽  
N Losses ◽  
Total N ◽  
The Impact

Abstract The varied and wide-reaching impacts of climate change are occurring across heterogeneous landscapes. Despite the known importance of soils in mediating biogeochemical nutrient cycling, there is little experimental evidence of how soil characteristics may shape ecosystem response to climate change. Our objective was to clarify how soil characteristics modify the impact of climate changes on carbon and nutrient leaching losses in temperate forests. We therefore conducted a field-based mesocosm experiment with replicated warming and snow exclusion treatments on two soils in large (2.4 m diameter), in-field forest sapling mesocosms. We found that nutrient loss responses to warming and snow exclusion treatments frequently varied substantially by soil type. Indeed, in some cases, soil type nullified the impact of a climate treatment. For example, warming and snow exclusion increased nitrogen (N) losses on fine soils by up to four times versus controls, but these treatments had no impact on coarse soils. Generally, the coarse textured soil, with its lower soil-water holding capacity, had higher nutrient losses (e.g., 12-17 times more total N loss from coarse than fine soils), except in the case of phosphate, which had consistently higher losses (23-58%) from the finer textured soil. Furthermore, the mitigation of nutrient loss by increasing tree biomass varied by soil type and nutrient. Our results suggest that potentially large biogeochemical responses to climate change are strongly mediated by soil characteristics, providing further evidence of the need to consider soil properties in Earth system models for improving nutrient cycling and climate projections.

Assess 21st century Flash Drought in the United States using high resolution regional climate models

2021 ◽  
Author(s):  
Brandi Gamelin ◽  
Jiali Wang ◽  
V. Rao Kotamarthi
Keyword(s):  
Climate Change ◽  
United States ◽  
Soil Moisture ◽  
Climate Models ◽  
Wrf Model ◽  
The United States ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Regional Variability ◽  
Groundwater Levels

&lt;p&gt;Flash droughts are the rapid intensification of drought conditions generally associated with increased temperatures and decreased precipitation on short time scales.&amp;#160; Consequently, flash droughts are responsible for reduced soil moisture which contributes to diminished agricultural yields and lower groundwater levels. Drought management, especially flash drought in the United States is vital to address the human and economic impact of crop loss, diminished water resources and increased wildfire risk. In previous research, climate change scenarios show increased growing season (i.e. frost-free days) and drying in soil moisture over most of the United States by 2100. Understanding projected flash drought is important to assess regional variability, frequency and intensity of flash droughts under future climate change scenarios. Data for this work was produced with the Weather Research and Forecasting (WRF) model. Initial and boundary conditions for the model were supplied by CCSM4, GFDL-ESM2G, and HadGEM2-ES and based on the 8.5 Representative Concentration Pathway (RCP8.5). The WRF model was downscaled to a 12 km spatial resolution for three climate time frames: 1995-2004 (Historical), 2045-2054 (Mid), and 2085-2094 (Late). &amp;#160;A key characteristic of flash drought is the rapid onset and intensification of dry conditions. For this, we identify onset with vapor pressure deficit during each time frame. Known flash drought cases during the Historical run are identified and compared to flash droughts in the Mid and Late 21&lt;sup&gt;st&lt;/sup&gt; century.&lt;/p&gt;

Sign in / Sign up

Export Citation Format

Share Document