scholarly journals Increased soil temperature stimulates changes in carbon, nitrogen, and mass loss in the fine roots of Pinus koraiensis under experimental warming and drought

2019 ◽  
Vol 43 (1) ◽  
pp. 80-87 ◽  
Author(s):  
Seung Hyun HAN ◽  
Seongjun KIM ◽  
Hanna CHANG ◽  
Guanlin LI
Keyword(s):  
Soil Temperature ◽  
Mass Loss ◽  
Fine Roots ◽  
Pinus Koraiensis ◽  
Experimental Warming

Effects of nitrogen deposition on litter decomposition and nutrient release mediated by litter types and seasonal change in a temperate forest

2020 ◽  
Vol 100 (1) ◽  
pp. 11-25 ◽  
Author(s):  
Guoyong Yan ◽  
Xiongde Dong ◽  
Binbin Huang ◽  
Honglin Wang ◽  
Ziming Hong ◽  
...  
Keyword(s):  
Mass Loss ◽  
Litter Decomposition ◽  
Nutrient Release ◽  
N Deposition ◽  
Pinus Koraiensis ◽  
N Addition ◽  
Entire Study ◽  
Mixed Litter ◽  
Negative Effect ◽  
Four Levels

We conducted a field experiment with four levels of simulated nitrogen (N) deposition (0, 2.5, 5, and 7.5 g N m−2 yr−1, respectively) to investigate the response of litter decomposition of Pinus koraiensis (PK), Tilia amurensis (TA), and their mixture to N deposition during winter and growing seasons. Results showed that N addition significantly increased the mass loss of PK litter and significantly decreased the mass loss of TA litter throughout the 2 yr decomposition processes, which indicated that the different responses in the decomposition of different litters to N addition can be species specific, potentially attributed to different litter chemistry. The faster decomposition of PK litter with N addition occurred mainly in the winter, whereas the slower decomposition of TA litter with N addition occurred during the growing season. Moreover, N addition had a positive effect on the release of phosphorus, magnesium, and manganese for PK litter and had a negative effect on the release of carbon, iron, and lignin for TA litter. Decomposition and nutrient release from mixed litter with N addition showed a non-additive effect. The mass loss from litter in the first winter and over the entire study correlated positively with the initial concentration of cellulose, lignin, and certain nutrients in the litter, demonstrating the potential influence of different tissue chemistries.

scholarly journals Environmental Factors and Soil CO2Emissions in an Alpine Swamp Meadow Ecosystem on the Tibetan Plateau in Response to Experimental Warming

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Bin Wang ◽  
Ben Niu ◽  
Xiaojie Yang ◽  
Song Gu
Keyword(s):  
Tibetan Plateau ◽  
Environmental Factors ◽  
Soil Temperature ◽  
Environmental Factor ◽  
Seasonal Variations ◽  
Environmental Control ◽  
The Tibetan Plateau ◽  
Control Mechanisms ◽  
Experimental Warming ◽  
Upward Trend

We examined the response of soil CO2emissions to warming and environmental control mechanisms in an alpine swamp meadow ecosystem on the Tibetan Plateau. Experimental warming treatments were performed in an alpine swamp meadow ecosystem using two open-top chambers (OTCs) 40 cm (OA) and 80 cm (OB) tall. The results indicate that temperatures were increased by 2.79°C in OA and 4.96°C in OB, that ecosystem CO2efflux showed remarkable seasonal variations in the control (CK) and the two warming treatments, and that all three systems yielded peak values in August of 123.6, 142.3, and 166.2 g C m−2 month−1. Annual CO2efflux also showed a gradual upward trend with increased warming: OB (684.1 g C m−2 year−1) > OA (580.7 g C m−2 year−1) > CK (473.3 g C m−2 year−1). Path analysis revealed that the 5 cm depth soil temperature was the most important environmental factor affecting soil CO2emissions in the three systems.

Root dynamics in sprouting tanoak forests of southwestern Oregon

2008 ◽  
Vol 38 (7) ◽  
pp. 1855-1866 ◽  
Author(s):  
Glenn R. Ahrens ◽  
Michael Newton
Keyword(s):  
Soil Temperature ◽  
Fine Roots ◽  
Shoot Biomass ◽  
Leaf Biomass ◽  
Strongly Correlated ◽  
Root Dynamics ◽  
Fold Reduction ◽  
Lithocarpus Densiflorus ◽  
Shoot Dynamics ◽  
Proportional Increase

Root and shoot biomass were measured across an 8 year chronosequence in mature and regenerating stands of tanoak ( Lithocarpus densiflorus (Hook. & Arn.) Rehd.), following cutting and burning in mature tanoak forests. Tanoak stump sprouts rapidly replaced leaf biomass but did not maintain preexisting root systems. Rather, root biomass declined for several years, with the largest proportional decline in extra-fine roots. Four years after harvest, live root biomasses in diameter classes 0.25–2.00 and 0.25–5.00 mm were 25% and 30% of values in mature tanoak forests, respectively. The proportion of dead roots was strongly correlated with maximum summer soil temperature. Root/shoot ratios recovered to preharvest values by age 3–4 years, at which time the live biomass of fine roots and leaf biomass was approximately 30%–40% of values in mature forest. From age 4 to 8 years, stable root/shoot ratios were associated with a three- to four-fold reduction in growth rate of leaf biomass and a proportional increase in growth of fine roots. These findings support the general theory of a functional root–shoot balance in tanoak and suggest a possible role for soil temperature in postharvest root dynamics. Improved understanding of postdisturbance root and shoot dynamics in tanoak will help identify competitive interactions and priorities for vegetation management decisions in establishment of conifers following harvest of mixed conifer–hardwood forests of southwestern Oregon and northern California.

Responses of soil temperature, moisture and respiration to experimental warming in a subtropical evergreen broad-leaved forest in Ailao Mountains, Yunnan

2015 ◽  
Vol 35 (22) ◽  
Author(s):  
张一平 ZHANG Yiping ◽  
武传胜 WU Chuangsheng ◽  
梁乃申 LIANG Naishen ◽  
沙丽清 SHA Liqing ◽  
罗鑫 LUO Xing ◽  
...  
Keyword(s):  
Soil Temperature ◽  
Experimental Warming ◽  
Broad Leaved Forest ◽  
Leaved Forest

Senescence-related changes in nitrogen in fine roots: mass loss affects estimation

2009 ◽  
Vol 29 (5) ◽  
pp. 715-723 ◽  
Author(s):  
Justin M. Kunkle ◽  
Michael B. Walters ◽  
Richard K. Kobe
Keyword(s):  
Mass Loss ◽  
Fine Roots

scholarly journals The Dynamics of Mass Loss and Nutrient Release of Decomposing Fine Roots, Needle Litter and Standard Substrates in Hemiboreal Coniferous Forests

2021 ◽  
Vol 4 ◽  
Author(s):  
Kaie Kriiska ◽  
Krista Lõhmus ◽  
Jane Frey ◽  
Endla Asi ◽  
Naima Kabral ◽  
...  
Keyword(s):  
Mass Loss ◽  
Green Tea ◽  
Decomposition Rate ◽  
Soil Chemistry ◽  
Fine Roots ◽  
Nutrient Release ◽  
Coniferous Forests ◽  
Nitrogen Accumulation ◽  
Needle Litter ◽  
Initial Substrate

Litter decomposition is a key process that drives carbon and nutrient cycles in forest soils. The decomposition of five different substrate types was analyzed in hemiboreal coniferous forests, focusing on the mass loss and nutrient (N, P, and K) release of fine roots (FR) and needle litter in relation to the initial substrate and soil chemistry. A litterbag incubation experiment with site-specific FR and needle litter and three standard substrates (green and rooibos tea, α-cellulose) was carried out in four Norway spruce and four Scots pine-dominated stands in Estonia. Substrate type was the primary driver of mass loss and the decay rate of different substrates did not depend on the dominant tree species of the studied stands. Alpha-cellulose lost 98 ± 1% of the mass in 2-years, while the FR mass loss was on average 23 ± 2% after 3-years of decomposition. The FR decomposition rate could be predicted using a corresponding model of green tea, although the rate of FR decomposition is approximately five times lower than the rate of green tea in the first 3-years. The annual decomposition rate of the needle litter is rather constant in hemiboreal coniferous forests in the first 3 years. The initial substrate of fine roots or needle litter and soil chemistry jointly had a significant effect on mass loss in the later stage of decomposition. The critical N concentration for N release was lower for pine FR and needle litter (0.9–1.3% and 0.7–1.1%) compared to spruce (1.2–1.6% and 1.5–1.9%, respectively). The release rate of K depended on the initial K of substrate, while the release of N and P was significantly related to the initial C:N and N:P ratios, respectively. The results show the central role of soil and substrate initial chemistry in the decomposition of fine roots and needle litter across hemiboreal forests, especially at later stage (after 2 years) of decomposition. The slower decomposition and higher retention of N in the fine roots relative to needle litter suggests that fine roots have a substantial role in the carbon and nitrogen accumulation in boreal and hemiboreal forest ecosystems.

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