RESUMO
Soil heterogeneity is at a high level in the karst areas, which resulted from the complex habitat. On the one hand, plants have some adaptive strategies to such special habitats by forming certain morphological and physiological characteristics, which result in higher diversity of functional traits. One the other hand, plants improve the physical and chemical properties of soil through a series of life activities. The interactions between plants and soil drive ecosystem structure and function and its responses to global climate change. Here, we summarized the characteristics of soil hete-rogeneity in the karst areas, and reviewed the response of plant functional traits to soil and the feedback of plants to soil. It revealed the coupling mechanism between plants and soil in karst eco-system. We provided a future outlook, including future research contents and directions based on the current research status in this field, which aimed to provide theoretical reference for maintaining the structural and functional stability of fragile karst ecosystems.
Assuntos
Ecossistema , Solo , Plantas , Microbiologia do SoloRESUMO
Field sampling and indoor pipette method was used to analyze the variation of soil mechanical composition of shallow Karst fissures in response to rainfall under different land uses in Karst rocky desertification region in central Guizhou. Results would supply important scientific basis and direction for further research of soil leakage in the Karst areas. The results showed that silt was the dominant component in soil mechanical composition of shallow Karst fissures, with a content of 57%. In response to rainfall, the contents of silt and clay were increased and that of fine sand was reduced in slope cropland, while the content of fine sand was reduced and that of silt was increased in grassland. The changes of mechanical composition of shallow Karst fissures in forest and shrub land were irregular. Moreover, there was a positive correlation between rainfall and the sand content of shallow Karst fissures. The fissures of land use types had effects on the changes of silt and extremely coarse sand contents with the increase of soil depth, with a decreasing trend of silt.
Assuntos
Conservação dos Recursos Naturais , Solo , China , Argila , FlorestasRESUMO
Studying soil erosion process and mechanism on Karst slopes has important practical and guiding significance for controlling soil and water loss and preventing rocky desertification in Karst region. The soil erosion process and characteristics on Karst slopes were explored by artificial simulation rainfall experiment. Results showed that the soil and water loss largely came from underground hole (crack) when rainfall intensity was in the range of 30 and 50 mm·h-1, while soil erosion occurred primarily in soil surface when rainfall intensity was 80 mm·h-1. Surface runoff modulus and transport rate both increased with increasing slope, and decreased with increasing underground hole (crack) degree. The underground runoff modulus varied from 0.37 to 0.52, and the underground transport rate changed from 0.81 to 1.93 g·min-1. They both decreased with increasing slope while increased firstly and then decreased with increasing rainfall intensity.
Assuntos
Chuva , Solo , Movimentos da Água , Conservação dos Recursos Naturais , Sedimentos Geológicos , ÁguaRESUMO
By the method of spatiotemporal substitution and taking a slope farmland and a natural Platycladus orientailis L. forest as the controls, this paper studied the dynamic changes of soil microbial biomass, microbial respiration, metabolic quotient (qCO2) and physicochemical properties under the Caragana korshinkii and Hippophae rhamnoides plantations with different restoration age in loess hilly area. The results showed that with the increasing restoration age of the shrubs, soil physicochemical properties improved obviously, and soil microbial biomass had a significant increase. After 7 years restoration of C. korshinkii plantation, soil microbial biomass C increased apparently, compared with that in farmland, and the increments after each 5-7 years were all significant. Microbial biomass N and P had no significant increase in the first 13 years but kept relatively stable in the 20-30 years restoration of C. korshinkii plantation, and were significantly higher than those in farmland but lower than those under P. orientailis plantation after 30 years restoration of C. korshinkii plantation. Soil microbial respiration was enhanced with the increasing restoration age of the shrubs, with the peak in the 20-25 years restoration. After then, it decreased rapidly, and bottomed out in the 30 years restoration. qCO2 was significantly higher under P. orientailis plantation than in farmland in the early periods of shrubs restoration, and then decreased rapidly. After 30 years restoration of C. korshinkii plantation, qCO2 was lower than that in farmland but still much higher than that under P. orientailis plantation. Different shrub plantations had different effects on soil properties. H. rhamnoides with the same restoration age of C. korshinkii contributed more to the increase of soil microbial biomass and respiration. There were significant correlations between the restoration age of test shrub plantations and the microbial biomass, qCO2, and physicochemical properties of soil. It was considered that vegetation restoration could be a feasible way in improving the eco-environment and soil quality in loess hilly area, but a longer period should be required to reach to the climax before vegetation destruction. It is necessary to strengthen and improve forest management to interfere and accelerate plant succession for a sustainable and healthy ecosystem.
