Plateau pikas (Ochotona curzoniae) at low densities have no destructive effect on winter pasture in alpine meadows

2020 ◽  
Vol 42 (1) ◽  
pp. 55
Author(s):  
W. R. Wei ◽  
J. D. He ◽  
Q. Y. Zheng

The plateau pika (Ochotona curzoniae) is a common small mammal species present in the alpine meadow ecosystem on the Qinghai-Tibetan Plateau (QTP), and is regarded as a pest in alpine meadows when population density exceeds a certain threshold. However, whether pikas with a low population density have a detrimental effect on alpine meadows in winter pasture is unknown. Vegetation and soil were sampled in eight individual pika patchy home ranges and eight control areas, and we found vegetation and soil properties showed different trends in the pika home ranges. Plateau pika activity significantly increased the below-ground biomass, soil pH and total potassium, but had no significant effect on the plant species richness or diversity, soil moisture, NH4-N, NO3-N, total phosphorus, available phosphorus and soil organic content. However, plateau pika activity reduced some vegetation and soil properties (e.g. vegetation cover, vegetation height, aboveground biomass, graminoids, soil bulk density and available potassium). These results imply that pika activity may improve some soil nutrients but have no destructive effect on winter pasture at a low population density.

2013 ◽  
Vol 78 (1) ◽  
pp. 68-72 ◽  
Author(s):  
Jiapeng Qu ◽  
Wenjing Li ◽  
Min Yang ◽  
Weihong Ji ◽  
Yanming Zhang

Geoderma ◽  
2021 ◽  
Vol 397 ◽  
pp. 115098
Author(s):  
Xiao Pan Pang ◽  
Huan Yang ◽  
Xiao Xing Wei ◽  
Zheng Gang Guo

2021 ◽  
Author(s):  
Jun Qiu ◽  
Cang Ma ◽  
Fang-Fang Li

Plateau pikas (Ochotona curzoniae) are regarded as one of the main reasons for the degradation of alpine meadows in the Qinghai-Tibet Plateau (QTP). The population density of plateau pikas is directly related to the degree of grassland damage. In this study, a one-week field observation was conducted in the southeastern QTP in August 2019. Based on the photos and videos, the random encounter model (REM) was used to estimate the population density of plateau pikas, and the frequency of different behaviors was counted. The effects of water source distance and terrain on the distribution of plateau pikas were also investigated. In addition, the frequency of different behaviors of plateau pikas under different population densities was also explored. The observations and knowledge derived from this study provide a reference for the population control of plateau pikas.


Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 171
Author(s):  
Gaurav Mishra ◽  
Rosa Francaviglia

Northeast (NE) India is a typical tropical ecosystem with a luxuriant forest vegetation cover, but nowadays forests are under stress due to exploitation and land use changes, which are known to affect soil health and productivity. However, due to a scarcity of data, the influence of land uses and altitude on soil properties of this peculiar ecosystem is poorly quantified. This study presents the changes in soil properties in two districts of Nagaland (Mon and Zunheboto) in relation to land uses (forest, plantation, jhum and fallow jhum), altitude (<500 m, 500–1000 m, >1000 m) and soil texture (coarse, medium, fine). For this, a random soil sampling was performed in both the districts. Results indicated that soil organic carbon (SOC) stocks and available potassium (K) were significantly influenced by land uses in the Mon district, while in Zunheboto a significant difference was observed in available phosphorus (P) content. SOC stocks showed an increasing trend with elevation in both districts. The influence of altitude on P was significant and the maximum concentration was at lower elevations (<500 m). In Mon, soil texture significantly affected SOC stocks and the available N and P content. The variability in soil properties due to land uses, altitudinal gradients and textural classes can be better managed with the help of management options, which are still needed for this ecosystem.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Víctor Fernández-García ◽  
Elena Marcos ◽  
Sara Huerta ◽  
Leonor Calvo

Abstract Background Wildfires are one of the major environmental concerns in Mediterranean ecosystems. Thus, many studies have addressed wildfire impacts on soil and vegetation in Mediterranean forests, but the linkages between these ecosystem compartments after fire are not well understood. The aim of this work is to analyze soil-vegetation relationships in Mediterranean burned forests as well as the consistency of these relationships among forests with different environmental conditions, at different times after fire, and among vegetation with different functional traits. Results Our results indicate that study site conditions play an important role in mediating soil-vegetation relationships. Likewise, we found that the nature of soil-vegetation relationships may vary over time as fire effects are less dominant in both ecosystem compartments. Despite this, we detected several common soil-vegetation relationships among study sites and times after fire. For instance, our results revealed that available P content and stoichiometry (C:P and N:P) were closely linked to vegetation growth, and particularly to the growth of trees. We found that enzymatic activities and microbial biomass were inversely related to vegetation growth rates, whereas the specific activities of soil enzymes were higher in the areas with more vegetation height and cover. Likewise, our results suggest that resprouters may influence soil properties more than seeders, the growth of seeders being more dependent on soil status. Conclusions We provide pioneer insights into how vegetation is influenced by soil, and vice-versa, in Mediterranean burned areas. Our results reflect variability in soil-vegetation relationships among study sites and time after fire, but consistent patterns between soil properties and vegetation were also detected. Our research is highly relevant to advance in forest science and could be useful to achieve efficient post-fire management.


2015 ◽  
Vol 12 (2) ◽  
pp. 34-38 ◽  
Author(s):  
Ashim Kumar Saha ◽  
Apu Biswas ◽  
Abdul Qayyum Khan ◽  
Md. Mohashin Farazi ◽  
Md. Habibur Rahman

Long-term tea cultivation has led to degradation of the soil. Old tea soils require rehabilitation for restoring soil health. Soil rehabilitation by growing different green crops can break the chain of monoculture of tea. An experiment was conducted at The Bangladesh Tea Research Institute (BTRI) Farm during 2008-2011 to find out the efficiency of different green crops on the improvement of soil properties. Four green crops such as Guatemala, Citronella, Mimosa and Calopogonium were grown to develop the nutritional value of the degraded tea soil. Soil samples were collected and analyzed before and at the end of experiment. Soil pH was increased in all four green crops treated plots with the highest increase in Citronella treated plots (from 4.1 to 4.5). Highest content of organic carbon (1.19%) and total nitrogen (0.119%) were found in Mimosa and Calopogonium treated plots, respectively. Concentration of available phosphorus, calcium and magnesium in all green crops treated plots were above the critical values, while available potassium content was above the critical value in Guatemala, Citronella and Mimosa treated plots. Changes in soil pH and available potassium were significant, while changes in organic carbon content, total nitrogen and available calcium were insignificant. Changes in available phosphorus and magnesium were significant. The Agriculturists 2014; 12(2) 34-38


PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0241794
Author(s):  
Maroua Jerbi ◽  
Sonia Labidi ◽  
Anissa Lounès-Hadj Sahraoui ◽  
Hatem Chaar ◽  
Faysal Ben Jeddi

Whereas the role of arbuscular mycorrhizal fungi (AMF) in plant growth improvement has been well described in agroecosystems, little is known about the effect of environmental factors on AMF root colonization status of barley, the fourth most important cereal crop all over the world. In order to understand the influence of environmental factors, such as climatic and soil physico-chemical properties, on the spontaneous mycorrhizal ability of barley (Hordeum vulgare L.), a field investigation was conducted in 31 different sites in sub-humid, upper and middle semi-arid areas of Northern Tunisia. Mycorrhizal root colonization of H. vulgare varied considerably among sites. Principal component analysis showed that barley mycorrhization is influenced by both climatic and edaphic factors. A partial least square structural equation modelling (PLS-SEM) revealed that 39% (R²) of the total variation in AMF mycorrhizal rate of barley roots was mainly explained by chemical soil properties and climatic characteristics. Whereas barley root mycorrhizal rates were inversely correlated with soil organic nitrogen (ON), available phosphorus amounts (P), altitude (Z), average annual rainfall (AAR), they were directly correlated with soil pH and temperature. Our results indicated that AMF root colonization of barley was strongly related to climatic characteristics than chemical soil properties. The current study highlights the importance of the PLS-SEM to understand the interactions between climate, soil properties and AMF symbiosis of barley in field conditions.


Author(s):  
Vítězslav Vlček ◽  
Miroslav Pohanka

Soil samples (n = 11) were collected in the chernozem areas of the Czech Republic (the Central Europe) from the topsoil and used as representative samples. All sampling areas have been used for agricultural purposes (arable soil) and they were selected as typical representatives of agricultural soil. These samples represented the soil with same genesis (to reduction differencies between soil types) but with different soil properties (physical and chemical). Complete chemical and physical analyses were made for confirmation of copper adsorption on solid phase: we analysed the particle size distribution, content of oxidizable carbon (Cox), the cation exchange capacity (CEC), supply of exchange calcium, magnesium, sodium, phosphorus and potassium, soil reaction and the total supply of Fe, Al, Mn, Ca, Mg, K, P and N. The strongest simple correlation between analysed soil properties and copper concentration had content of available magnesium (r = 0.44) and available phosphorus (r = −0.51). In the case of multiple correlations (i. e. collective influence of multiple soil properties) had the strongest influence combination of clay, soil reaction, total content of phosphorus, available magnesium and available phosphorus. The main influence of phosphorus and magnesium is evident. We suppose that copper and phosphorus enter into specific complex. Influence of these five soil properties can explain 92.7 % (r = 0.927) changes in the content of copper changes in the experiment.


1995 ◽  
Vol 18 (1) ◽  
pp. 71
Author(s):  
J.L. Gardner ◽  
M. Serena

The Water Rat Hydromys chrysogaster is Australia&apos;s largest amphibious rodent, occupying freshwater rivers, lakes, and coastal and estuarine habitats throughout the continent (Watts and Aslin 1981). Little is known of the species&apos; social organisation or use of space in the wild although Harris (1978) suggested that adults might be intrasexually aggressive. The home ranges of all sex and age classes overlap to some extent but home ranges of adults of the same sex appear to overlap less (Harris 1978). Adult males occupy the largest home ranges which overlap those of one or more females. In captivity individuals kept in groups form hierarchies in which only the dominant females usually breed successfully (Olsen 1982). Fighting occurs primarily among males, with the highest incidence of injuries observed at the beginning of the main September-March breeding season (Olsen 1980, 1982). The results of trapping studies indicate that population density may vary considerably, with the greatest numbers of animals typically occupying man-modified habitats such as irrigation channels or fish farms (McNally 1960, Watts and Aslin 1981, Smales 1984). Aggressive behaviour appears to be related to pelage colour (phenotype) and population density; the higher the density the greater the number of injured individuals (Olsen 1980).


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