scholarly journals Variation of Leaf Carbon Isotope in Plants in Different Lithological Habitats in a Karst Area

Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 356
Author(s):  
Jun Zou ◽  
Lifei Yu ◽  
Zongsheng Huang

Drought is the major factor that limits vegetation recovery in rocky desertification areas. The leaf carbon isotope (δ13C) value is related to plant water-use efficiency (WUE) and is of great significance in revealing the WUE characteristics of species in karst areas. Measurements of the δ13C value in plant leaves and the nutrient and water contents of lithologic soils were obtained for six woody species (cypress, Cupressus funebris Endl.; mansur shrub, Coriaria nepalensis Wall.; camphor, Cinnamomum bodinieri Levl.; birch, Betula luminifera H. Winkl.; alder, Alnus cremastogyne Burk. and dyetree, Platycarya longipes Wu.) planted in three different lithologic soil types (dolomite, dolomite sandstone, limestone) in the karst area of Guizhou Province. The results showed that C. funebris in the dolomite sandstone soil had the highest δ13C value (−27.19‰), whereas C. bodinieri in the limestone soil had the lowest δ13C value (−31.50‰). In terms of lithology, the average leaf δ13C values were −28.66‰ (dolomitic sandstone), −28.83‰ (dolomite), and −29.46‰ (limestone). The δ13C values of C. funebris and A. cremastogyne were significantly lower in the limestone soil than in the dolomite and dolomite sandstone soil, indicating that the WUE of some tree species is affected by soil conditions under different lithological development processes. Moreover, the relationship between the δ13C value in the leaves and the comprehensive soil conditions varied among the species, and the δ13C value was negatively correlated with the soil water content in all three soil types. Our study provides basic data on the composition characteristics of the δ13C value of tree species, which is beneficial for the selection of tree species for vegetation restoration and afforestation in karst areas.

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 991 ◽  
Author(s):  
Yinmao Zhao ◽  
Weihong Liao ◽  
Xiaohui Lei

A groundwater model is needed to describe the complex groundwater confluence process of the groundwater system in karst areas. This is because surface water flows through dolines, grikes, and by other means and is directly exchanged with the groundwater. In this study, using the Xin’anjiang model, the conversion of surface water into groundwater and the influence of multiple series-parallel underground reservoirs on groundwater confluence through the generalization of dolines in karst areas were simulated. The water cycle process in the Sancha River Basin was simulated with measured data using multiobjective particle swarm optimization. Then, model parameters were validated with measured runoff data and compared with simulation results obtained using the traditional Xin’anjiang model based on its optimal parameters. The results showed that the determination coefficients of all hydrological stations over the study period were >0.76, and the Nash efficiency coefficient was >0.76, which were better than those for the improved Xin’anjiang model. Next, the simulation accuracy of the flood period in the karst area was analyzed. The model achieved a high fitting rate for the main flood peaks in a year, and the passing rate for the worst hydrological stations was 53%. Finally, the influence of karst development on the runoff was examined. The results indicate that different karst development stages and the heterogeneity of the karst in the basin have different effects on runoff.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Liying Liu

AbstractThis paper presents the assessment of water resource security in the Guizhou karst area, China. A mean impact value and back-propagation (MIV-BP) neural network was used to understand the influencing factors. Thirty-one indices involving five aspects, the water quality subsystem, water quantity subsystem, engineering water shortage subsystem, water resource vulnerability subsystem, and water resource carrying capacity subsystem, were selected to establish an evaluation index of water resource security. In addition, a genetic algorithm and back-propagation (GA-BP) neural network was constructed to assess the water resource security of Guizhou Province from 2001 to 2015. The results show that water resource security in Guizhou was at a moderate warning level from 2001 to 2006 and a critical safety level from 2007 to 2015, except in 2011 when a moderate warning level was reached. For protection and management of water resources in a karst area, the modes of development and utilization of water resources must be thoroughly understood, along with the impact of engineering water shortage. These results are a meaningful contribution to regional ecological restoration and socio-economic development and can promote better practices for future planning.


2021 ◽  
Vol 18 (5) ◽  
pp. 1793-1801
Author(s):  
Heejun Han ◽  
Jeomshik Hwang ◽  
Guebuem Kim

Abstract. In order to determine the origins of dissolved organic matter (DOM) occurring in the seawater of Sihwa Lake, we measured the stable carbon isotope ratios of dissolved organic carbon (DOC-δ13C) and the optical properties (absorbance and fluorescence) of DOM in two different seasons (March 2017 and September 2018). Sihwa Lake is enclosed by a dike along the western coast of South Korea, and the water is exchanged with the Yellow Sea twice a day through the sluice gates. The DOC concentrations were generally higher in lower-salinity waters in both periods, and excess of DOC was also observed in 2017 in high-salinity waters. Here, the excess DOC represents any DOC concentrations higher than those in the incoming open-ocean seawater. The excess DOC occurring in the lower-salinity waters originated mainly from marine sediments of tidal flats, based on the DOC-δ13C values (-20.7±1.2 ‰) and good correlations among the DOC, humic-like fluorescent DOM (FDOMH), and NH4+ concentrations. However, the origins of the excess DOC observed in 2017 appear to be from two different sources: one mainly from marine sources such as biological production based on the DOC-δ13C values (−19.1 ‰ to −20.5 ‰) and the other mainly from terrestrial sources by land–seawater interactions based on its depleted DOC-δ13C values (−21.5 ‰ to −27.8 ‰). This terrestrial DOM source observed in 2017 was likely associated with DOM on the reclaimed land, which experienced extended exposure to light and bacterial degradation as indicated by the higher spectral slope ratio (SR) of light absorbance and no concurrent increases in the FDOMH and NH4+ concentrations. Our study demonstrates that the combination of these biogeochemical tools can be a powerful tracer of DOM sources and characteristics in coastal environments.


2021 ◽  
Author(s):  
Anjun Lan ◽  
Zemeng Fan ◽  
Qingsong Zhao ◽  
Xuyang Bai

Abstract How to explicitly understanding the soil erosion intensity change in different geomorphological types is one of key issues in the field of soil and water conservation. According to classification criterion of soil erosion intensity of China, the spatial soil erosion data with the resolution of 10 m×10m in Guizhou Province were obtained by combing with the multi-resolution remote sensing data of ALOS, ZY-3, GF-1, Landsat and GDEMV2, and 2762 field sampling data in 2010 and 2015, respectively. a spatial analysis model of soil erosion was improved to analyze the spatiotemporal change of soil erosion intensity in karst and non karst area of Guizhou province, which involved the spatial soil erosion data and different geomorphological type data of Guizhou province. The results show that the soil erosion intensity decreased by 6468.13km 2 in Guizhou Province from 2010 to 2015. The dynamic change intensity in the high-altitude area is larger than in the low-altitude area. The soil change intensity in karst area is higher than in non karst area, especially in the high and middle elevation area in Guizhou province. Moreover, the decreasing ratio of soil erosion intensity in karst area is generally larger than in non karst area, which can be used to explain that the ecological restoration projects and water soil conservation polices carried out in karst area has a good effect, especially in western of Guizhou province from 2010 to 2015, one the other hand, the soil erosion in non karst area should also be focused by local government in the future.


2020 ◽  
Vol 76 (1) ◽  
pp. 84-98
Author(s):  
Oldřich Fejfar ◽  
Wighart v. Koenigswald ◽  
Martin Sabol

The original fossil record of Allosorex stenodus Fejfar, 1966 from Ivanovce (late Ruscinian, MN 15b) is redescribed and supplemented by the description of so far unpublished fossil remains, including upper dentition (P4 and M3) and a humerus fragment as well as the enamel microstructure analysis of m2. Based on the critical evaluation of other fossil remains from sites in Romania, Hungary, and France, the Ivanovce fossils are so far the only unquestionable recorded finds of A. stenodus in Europe, which can be considered as a local early Pliocene (MN 15) endemic species. Its occurrence is connected with the forested karst area along a broad valley of “pre-Váh” River, ecologically and climatically resembling the environment of modern karst areas in south-eastern Asia. Based on enamel microstructure analysis and unique mandible and dentition morphological characters, a separate taxonomical status of the species is also discussed.


2016 ◽  
Author(s):  
Matheus Henrique Nunes ◽  
Matthew P. Davey ◽  
David Anthony Coomes

Abstract. Understanding the causes of variation in plant functional traits is a central issue in ecology, particularly in the context of global change. Analyses of the drivers of traits variation based on thousands of tree species are starting to unravel patterns of variation at the global scale, but these studies tend to focus on interspecific variation, and the contribution of intraspecific changes remains less well understood. Hyperspectroscopy is a recently developed technology for estimating the traits of fresh leaves. Few studies have evaluated its potential for assessing inter- and intra-specific trait variability in community ecology. Working with 24 leaf traits for European tree species on contrasting soil types, found growing on deep alluvial soils and nearby shallow chalk soils, we ask: (i) What contribution do soil type and species identity make to trait variation? (ii) When traits are clustered into three functional groups (light capture and growth, leaf structure and defence, as well as rock-derived nutrients), are some groups more affected by soil than others? (iii) What traits can be estimated precisely using field spectroscopy? (iv) Can leaf spectra be used to detect inter-soil as well as inter-specific variation in traits? The contribution of species and soil-type effects to variation in traits were evaluated using statistical analyses. Foliar traits were predicted from spectral reflectance using partial least square regression, and so inter- and intra-specific variation. Most leaf traits varied greatly among species. The effects of soil type were generally weak by comparison. Macronutrient concentrations were greater on alluvial than chalk soils while micronutrient concentration showed the opposite trend. However, structural traits, as well as most pigments and phenolic concentrations varied little with soil type. Field spectroscopy provided accurate estimates of species-level trait values, but was less effective at detecting subtle variation of rock-derived nutrients between soil types. Field spectroscopy was a powerful technique for estimating cross-species variation in foliar traits and Si predictions using spectroscopy appear to be promising. However, it was unable to detect subtle within-species variation of traits associated with soil type.


Phytotaxa ◽  
2021 ◽  
Vol 483 (1) ◽  
pp. 75-79
Author(s):  
XIONG LI ◽  
LEI WU ◽  
XUN-LIN YU

Aster jiangkouensis (Asteraceae), a new species from karst areas of southwestern Wuling Mountain, Guizhou province, China, is described and illustrated. It is most similar to A. huangpingensis, but differs from the latter in having inconspicuously triplinerved leaves, ovate to oblong-lanceolate leaf blades, cylindric-campanulate involucre. A line drawing, photographic image and preliminary conservation status of the new species are provided.


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