Variations of the biodiversity and carbon functions of karst forests in two morphologically different sites in southwestern China

Author(s):  
Libin Liu ◽  
Jian Ni

Knowledge of the biodiversity and carbon (C) functions of karst forests is scarce. This study comprehensively compared the species diversity and floristic characteristics, biomass and its allocation, leaf and soil C and nitrogen (N) concentrations, and photosynthetic capacity of dominant tree species between peak clump depression (PCD)-type and plateau surface (PS)-type karst forests on the basis of two large plots (i.e., 1 and 2 ha, respectively) in southwestern China. Results showed that PCD-type karst forest exhibits higher biodiversity and more tropical family and genus types than PS-type karst forest. These two types of karst forest presented similar total biomass, but PCD-type karst forest allocated more biomass to supporting roots and less biomass to absorbing roots. PS-type karst forest had higher C/N ratios in leaves and soils than PCD-type karst forest. Deciduous tree species in PS-type karst forest had low net photosynthetic rates, resulting in lower net photosynthetic rate in PS-type karst forest than in PCD-type karst forest. Species richness and C storage in the karst morphologies would be considerably enhanced if degraded vegetation in different types of karst area could be successfully restored to forests according to respective morphological and vegetation features. A comprehensive understanding of the biodiversity and C functions of karst vegetation is essential to biodiversity conservation, regional C storage estimation, vegetation management and restoration, and potential global change mitigation.

2021 ◽  
Author(s):  
Lucie Hublova ◽  
Jan Frouz

<p>Soils and forest soil in particular represent important pools of carbon (C). Here, we present a quantitative review of common garden experiments in which various tree species were planted alongside each other in European countries to answer following questions: Does soil sequester more C under broadleaf than under conifer trees? and How do the effects of tree species and litter quality on soil C sequestration change with soil development (i.e., maturity) and other soil properties?<strong> </strong>We found that the effects of broadleaf and coniferous trees on C sequestration differed with the stage of soil development. In mature soils, more C was stored under coniferous trees than under broadleaf trees. In soils in early stages of soil development, on post-mining spoil heaps, the opposite trend was found, i.e., more C was stored under broadleaf. C sequestration under broadleaf trees was highest in immature soils and in soils with high pH. C sequestration was negatively correlated with the litter C:N ratio in post-mining soils but not in other more mature soils. Similarly C sequestration was negatively correlated with the litter C:N  in alkaline soils and in soil with high clay content. These results suggest that C sequestration mechanisms differ in immature vs. mature soils such that C storage is greater under broadleaf trees in immature soils but is greater under coniferous trees in mature soils. The study was supported by LIFE17/IPE/CZ/000005 project</p>


2004 ◽  
Vol 20 (5) ◽  
pp. 587-590 ◽  
Author(s):  
Jennifer S. Powers ◽  
Melissa H. Kalicin ◽  
Meredith E. Newman

In a now classic study, Zinke (1962) showed that a single Pinus contorta tree growing on a sand dune along the coast of California modified the chemistry of the soil underneath its crown. He found distinct patterns of pH, exchangeable cations and nitrogen (N) content moving from the bole outward to the crown drip zone, because the acidic bark and stemflow were concentrated around the bole (Zinke 1962). Subsequent studies in temperate forests have also found tree species to affect soil chemical properties such as pH, organic carbon (C) and rates of N mineralization (Boerner & Koslowsky 1989, Boettcher & Kalisz 1990, Finzi et al. 1998). Presumably, these species-specific effects are caused by inter-specific differences in organic acid exudation, nutrient uptake, litter quality or quantity, decomposition rates or nutrient outputs (Binkley & Giardina 1998, Knops et al. 2002, Rhoades 1997). Regardless of the causes, species-generated soil heterogeneity has implications for stand-level estimates of biogeochemical processes such as soil C storage and N-cycling as well as implications for plant diversity and regeneration (Finzi et al. 1998). Although a number of studies have demonstrated that tree species modify soil environments in temperate forests or monospecific tree plantations in the tropics (Fisher 1995, Rhoades 1997), few studies have investigated these processes in species-rich tropical forests (but see Rhoades et al. 1994).


1995 ◽  
Vol 95 (3) ◽  
pp. 399-408 ◽  
Author(s):  
Elena Toll ◽  
Federico J. Castillo ◽  
Pierre Crespi ◽  
Michele Crevecoeur ◽  
Hubert Greppin

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Qiang Li ◽  
Yadan Huang ◽  
Shenglin Xin ◽  
Zhongyi Li

AbstractAlthough bacterioplankton play an important role in aquatic ecosystems, less is known about bacterioplankton assemblages from subtropical karst reservoirs of southwestern China with contrasting trophic status. Here, 16S rRNA gene next-generation sequencing coupled with water chemistry analysis was applied to compare the bacterioplankton communities from a light eutrophic reservoir, DL Reservoir, and a mesotrophic reservoir, WL Reservoir, in subtropical karst area of southwestern China. Our findings indicated that Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, Cyanobacteria and Verrucomicrobia dominated bacterioplankton community with contrasting relative frequency in the two subtropical karst reservoirs. Proteobacteria and Bacteroidetes were the core communities, which played important roles in karst biogeochemical cycles. Though WT, TN and DOC play the decisive role in assembling karst aquatic bacterioplankton, trophic status exerted significantly negative direct effects on bacterioplankton community composition and alpha diversity. Due to contrasting trophic status in the two reservoirs, the dominant taxa such as Enterobacter, Clostridium sensu stricto, Candidatus Methylacidiphilum and Flavobacteriia, that harbor potential functions as valuable and natural indicators of karst water health status, differed in DL Reservoir and WL Reservoir.


Author(s):  
Meng Na ◽  
Xiaoyang Sun ◽  
Yandong Zhang ◽  
Zhihu Sun ◽  
Johannes Rousk

AbstractSoil carbon (C) reservoirs held in forests play a significant role in the global C cycle. However, harvesting natural forests tend to lead to soil C loss, which can be countered by the establishment of plantations after clear cutting. Therefore, there is a need to determine how forest management can affect soil C sequestration. The management of stand density could provide an effective tool to control soil C sequestration, yet how stand density influences soil C remains an open question. To address this question, we investigated soil C storage in 8-year pure hybrid larch (Larix spp.) plantations with three densities (2000 trees ha−1, 3300 trees ha−1 and 4400 trees ha−1), established following the harvesting of secondary mixed natural forest. We found that soil C storage increased with higher tree density, which mainly correlated with increases of dissolved organic C as well as litter and root C input. In addition, soil respiration decreased with higher tree density during the most productive periods of warm and moist conditions. The reduced SOM decomposition suggested by lowered respiration was also corroborated with reduced levels of plant litter decomposition. The stimulated inputs and reduced exports of C from the forest floor resulted in a 40% higher soil C stock in high- compared to low-density forests within 8 years after plantation, providing effective advice for forest management to promote soil C sequestration in ecosystems.


2012 ◽  
Vol 42 (11) ◽  
pp. 1953-1964 ◽  
Author(s):  
Irene Fernandez ◽  
Juan Gabriel Álvarez-González ◽  
Beatríz Carrasco ◽  
Ana Daría Ruíz-González ◽  
Ana Cabaneiro

Forest ecosystems can act as C sinks, thus absorbing a high percentage of atmospheric CO2. Appropriate silvicultural regimes can therefore be applied as useful tools in climate change mitigation strategies. The present study analyzed the temporal changes in the effects of thinning on soil organic matter (SOM) dynamics and on soil CO2 emissions in radiata pine ( Pinus radiata D. Don) forests. Soil C effluxes were monitored over a period of 2 years in thinned and unthinned plots. In addition, soil samples from the plots were analyzed by solid-state 13C-NMR to determine the post-thinning SOM composition and fresh soil samples were incubated under laboratory conditions to determine their biodegradability. The results indicate that the potential soil C mineralization largely depends on the proportion of alkyl-C and N-alkyl-C functional groups in the SOM and on the microbial accessibility of the recalcitrant organic pool. Soil CO2 effluxes varied widely between seasons and increased exponentially with soil heating. Thinning led to decreased soil respiration and attenuation of the seasonal fluctuations. These effects were observed for up to 20 months after thinning, although they disappeared thereafter. Thus, moderate thinning caused enduring changes to the SOM composition and appeared to have temporary effects on the C storage capacity of forest soils, which is a critical aspect under the current climatic change scenario.


2016 ◽  
Vol 2 (4) ◽  
pp. 165-182 ◽  
Author(s):  
Chelsea L. Petrenko ◽  
Julia Bradley-Cook ◽  
Emily M. Lacroix ◽  
Andrew J. Friedland ◽  
Ross A. Virginia

Shrub species are expanding across the Arctic in response to climate change and biotic interactions. Changes in belowground carbon (C) and nitrogen (N) storage are of global importance because Arctic soils store approximately half of global soil C. We collected 10 (60 cm) soil cores each from graminoid- and shrub-dominated soils in western Greenland and determined soil texture, pH, C and N pools, and C:N ratios by depth for the mineral soil. To investigate the relative chemical stability of soil C between vegetation types, we employed a novel sequential extraction method for measuring organo-mineral C pools of increasing bond strength. We found that (i) mineral soil C and N storage was significantly greater under graminoids than shrubs (29.0 ± 1.8 versus 22.5 ± 3.0 kg·C·m−2 and 1.9 ± .12 versus 1.4 ± 1.9 kg·N·m−2), (ii) chemical mechanisms of C storage in the organo-mineral soil fraction did not differ between graminoid and shrub soils, and (iii) weak adsorption to mineral surfaces accounted for 40%–60% of C storage in organo-mineral fractions — a pool that is relatively sensitive to environmental disturbance. Differences in these C pools suggest that rates of C accumulation and retention differ by vegetation type, which could have implications for predicting future soil C pool storage.


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