Investigations on the Concentrations of K, Na Ca, Fe and P in Cymomorium from the Gobi Arid Desert Ecosystem, North-Western China

2012 ◽  
Vol 518-523 ◽  
pp. 4521-4531
Author(s):  
Wei Xuan Fang

Investigations on macronutrients (K, Na, Ca, Mg and P) and micronutrients (Fe) in windy sand- and salt-resistant plant species such as Cymomorium can help us to get a better understand their behaviours of ecologically environment geochemistry in the Gobi arid desert ecosystem. This study presents our investigations on the concentrations of K, Na Ca, Mg, Fe and P in xerophilous, sabulicolous, superhalophilous Cymomorium from the oasis ecosystem in the Beishan-Tianshan Gobi arid desert, northwestern China. The mean concentrations of macronutrients (K, Na, Ca, Mg and P) in Cymomorium Songaricum Rupr. are, respectively, 1.29±0.29 % K, 2.45±1.08 % Na, 2966±2038 μg g–1 Ca, 2038±1746 μg g–1Mg and 1462±457 μg g–1P. Although the average concentrations of Fe concentrations (341±361 μg g–1) is within the normal range of Fe in plant species, the maximum Fe concentrations (1400 μg g-1) were detected in Cymomorium stemmed from the sandy lowland around the Shaquanzi iron mine of the Xinjiang Uygur Autonomous Region in China. It suggested that the indigenous species of Cymomorium might be one of the appropriate xerohalophyte species to restore the vegetation of the oasis, saline land use for agriculture or arid environments destroyed by mining activities in the dry land because it may have higher ability to accumulate K, Na, Ca, Mg, Fe and P from saline soils, and it belongs to the native salt-resistant plant species.

Insects ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 665
Author(s):  
Marco Ferrante ◽  
Daniella M. Möller ◽  
Gabriella M. Möller ◽  
Yael Lubin ◽  
Michal Segoli

Acacia trees are keystone species in many arid environments, supporting high levels of plant and animal diversity. In Israel, the populations of Vachellia (formerly Acacia) tortilis (Forssk.) and V. raddiana (Savi) are declining at an alarming rate. Severe infestations by bruchid beetles (Coleoptera, Chrysomelidae) are among the major causes of seed mortality, but additional environmental stressors can reduce the defence level of the seeds, exacerbating their susceptibility to predators. In a hyper-arid desert ecosystem affected by two major oil spills (in 1975 and 2014), we quantified seed predation rates caused by insect granivores before and after the pods dropped to the ground. We recorded predation rates of up to 84% for both tree species, and higher predation rates at the ground level than in the canopy, suggesting that repeated infestations occur. These results reinforce the call to protect the populations of large ungulates such as gazelles, which kill the bruchids by feeding upon the pods, and promote seed germination and dispersion. We found no clear evidence of a negative effect of the oil spill on seed predation, indicating that oil pollution did not increase the vulnerability of the seeds to granivores even in trees affected by the recent oil spill.


Author(s):  
М. А. Babaeva ◽  
S. V. Osipova

The regularities of changes in the resistance of different groups of fodder plants to adverse conditions were studied. This is due to the physiological properties that allow them to overcome the harmful effects of the environment. As a result of research species - plant groups with great adaptive potential to the harsh continental semi-desert conditions were identified. Monitoring observation and experimental studies showed too thin vegetation cover as a mosaic, consisting of perennial xerophytic herbs and semishrubs, sod grasses, saltwort and wormwood, as well as ephemera and ephemeroids under the same environmental conditions, depending on various climatic and anthropogenic factors. This is due to the inability or instability of plant species to aggressive living environment. It results in horizontal heterogeneity of the grass stand, division into smaller structures, and mosaic in the vegetation cover of the Kochubey biosphere station. The relative resistance to moderate stress was identified in the following species from fodder plants Agropyron cristatum, A. desertorum, Festuca valesiaca, Cynodon dactylon, Avena fatua; as for strong increasing their abundance these are poorly eaten plant species Artemisia taurica, Atriplex tatarica, Falcaria vulgaris, Veronica arvensis, Arabidopsis thaliana and other. On the site with an increasing pressure in the herbage of phytocenoses the number of xerophytes of ruderal species increases and the spatial structure of the vegetation cover is simplified. In plant communities indigenous species are replaced by adventive plant species. The mosaic of the plant cover of phytocenoses arises due to the uneven distribution in the space of environmental formation, i.e. an edificatory: Salsola orientalis, S. dendroides, Avena fatua, Cynodon dactylon, Artemisia taurica, A. lercheanum, Xanthium spinosum, Carex pachystyli, under which the remaining components of the community adapt. Based on the phytocenotic indicators of pasture phytocenoses it can be concluded that the vegetation cover is in the stage of ecological stress and a decrease in the share of fodder crops and an increase in the number of herbs indicates this fact.


2021 ◽  
Vol 13 (12) ◽  
pp. 6660
Author(s):  
Marco Ferrante ◽  
Anuma Dangol ◽  
Shoshana Didi-Cohen ◽  
Gidon Winters ◽  
Vered Tzin ◽  
...  

Vachellia (formerly Acacia) trees are native to arid environments in Africa and the Arabian Peninsula, where they often support the local animal and plant communities acting as keystone species. The aim of this study was to examine whether oil pollution affected the central metabolism of the native keystone trees Vachellia tortilis (Forssk.) and V. raddiana (Savi), as either adults or seedlings. The study was conducted in the Evrona Nature Reserve, a desert ecosystem in southern Israel where two major oil spills occurred in 1975 and in 2014. Leaf samples were collected to analyze the central metabolite profiles from oil-polluted and unpolluted adult trees and from Vachellia seedlings growing in oil-polluted and unpolluted soils in an outdoor setup. We found that oil pollution had a stronger effect on one-year-old seedlings than on adult trees, reducing the levels of amino acids, sugars, and organic acids. While adult trees are mildly affected by oil pollution, the effects on young seedlings can cause a long-term reduction in the population of these keystone desert trees, ultimately threatening this entire ecosystem.


2016 ◽  
Vol 38 (1) ◽  
pp. 1 ◽  
Author(s):  
Richard B. Harris ◽  
Leah H. Samberg ◽  
Emily T. Yeh ◽  
Andrew T. Smith ◽  
Wang Wenying ◽  
...  

Livestock grazing is the principal land use in arid central Asia, and range degradation is considered a serious problem within much of the high-elevation region of western China termed the Qinghai-Tibetan Plateau (QTP). Rangeland degradation on the QTP is variously attributed to poor livestock management, historical-cultural factors, changing land tenure arrangements or socioeconomic systems, climate change, and damage from small mammals. Few studies have examined currently managed pastures using detailed data capable of isolating fine-scale livestock–vegetation interactions. The aim of the study was to understand how differences among livestock (primarily sheep) management strategies of pastoralists during winter affected subsequent rangeland condition and productivity. Plant species composition, annual herbage mass, and indicators of erosion were quantified during four summers (2009–2012) on winter pastures managed by 11 different pastoralists on QTP steppe rangeland in Qinghai Province, China. Data came from repeated-measurements on 317 systematically located permanent plots, as well as pastoralist interviews and the use of GPS-equipped livestock. Relationships between annual weather variation and herbage mass were modelled using an independent set of vegetation measurements obtained from livestock exclosures. Account was taken of inherent site differences among pastures. Annual variation in herbage mass was found to be best fitted by a model containing a negative function of winter-season temperature and a positive function of spring-season temperature. Accounting for annual and site effects, significant differences among pastoralists were found for most response variables, suggesting that individual heterogeneity among management approaches had consequences, even among neighbouring pastoralists. Annual herbage mass of preferred plant species was positively associated, whereas that of unpreferred species was negatively associated, with mean sheep density and intensity of use. However, the proportion of bare soil, an index of erosion, and annual herbage mass of unpreferred forbs were found to have positive relationships with sheep grazing pressure during the preceding winter, whereas live vegetation cover and annual herbage mass of preferred grasses were negatively related. Thus, on a spatial scale, pastoralists responded adaptively to the cover of preferred plant species while not responding to total annual herbage mass. Pastoralists stocked pastures more heavily, and livestock used regions within pastures more intensively, where preferred species had a higher cover. However, where sheep grazing pressure was high, downward temporal trends in the herbage mass of preferred species were exacerbated. Pastures that were stocked at a lower density did not experience the negative trends seen in those with a higher density.


1970 ◽  
Vol 3 ◽  
pp. 23-31 ◽  
Author(s):  
R. K. Manhas ◽  
M. K. Gautam ◽  
Deepa Kumari

In swamp distribution, dominance and survival of a species is very much governed by the soil moisture and period of flooding. The present study was conducted to classify the communities and plant species, and to have an idea about various associations of plants present in the swamp with respect to soil moisture. Two way indicator species analysis (TWINSPAN) classified the communities into four and plant species into eleven groups. The communities with least soil moisture were the first to be segregated and with highest soil moisture last. Similarly, the species growing in drier condition was clustered separately from the moisture loving indigenous species. Key words: TWINSPAN; vegetation; inland wetland; India DOI: 10.3126/jowe.v3i0.2433 Journal of Wetlands Ecology, (2009) Vol. 3, pp 23-31


REINWARDTIA ◽  
2018 ◽  
Vol 17 (2) ◽  
Author(s):  
Andrew Powling

POWLING, A. 2018. An assessment of present plant diversity on the Natewa Peninsula, Vanua Levu, Fiji. Reinwardtia 17(2): 125‒132. ‒‒ The Natewa Peninsula, part of the Fijian island of Vanua Levu, is naturally afforested but the forests have been extensively logged in the last 50 years. It is now planned to protect some of the forests from further logging by incorporating them into a National Park. A survey of plant species in the regenerating forests and surrounding land on the Peninsula was performed to assess the taxonomic and ecological diversity of the trees and shrubs, including figs and palms, and also the orchids presently to be found on the Peninsula. The degree of invasion by introduced plant species was also assessed. Of 67 tree and shrub species it was found that 17 were endemic to the Fijian islands, 40 others were indigenous and ten were introduced. The normal habitats of these species included dense, open and secondary forest, showing that trees with a range of ecological characteristics were still present. Endemic and indigenous species of both figs and palms were found, and also terrestrial and epiphytic orchids. No severe infestations of introduced species were observed. It is concluded that the forests of the Peninsula are of sufficient conservation value to justify National Park status. 


Author(s):  
Samson Shimelse Jemaneh

This study was conducted with the objectives of study investigates, compare, and try to describe the floristic composition and structure of the vegetation of exclosures and open grazing lands. A stratified preferential sampling design technique with flexible systematic model was used for data collection. Data on vegetation and environmental parameters were gathered from 120 quadrants (90 from restorations or exclosures of different ages and 30 from adjacent open grazing lands), of 20 m x 20 m (400 m2) size. Species richness and the presence or absence of herbaceous plants were recorded like soil samples in a 2 m x 2 m (4 m2) subplot inside each main quadrant from five points, one at each corner and one at the center.  A total of 142 plant species belonging to 118 genera and 52 families were identified. All exclosures displayed higher plant species richness, diversity, and aboveground standing biomass compared to the adjacent open grazing lands. Consideration of edaphic (e.g. soil total nitrogen, available phosphorus, CEC, exchangeable bases, soil pH and soil texture) and site (e.g. Stoniness, Grazing) variables will help to optimize the selection of areas for the establishment of future exclosures. Moreover, our study suggests that with time exclosures may increasingly obtain an important role as refugees and species pool similar to church forests and should be protected and managed in a sustainable manner. However, economic and social impacts of exclosures should be included in feasibility studies before establishing exclosures in the future.  Altitude, Grazing and some soil parameters like Mg were the major environmental factors in the division of the vegetation into plant community types. The result of the frequency distribution of woody species showed a high proportion of small-sized individuals in the lower diameter classes indicating good recruitment potential of the forest patches and the rare occurrence of large individuals. Such trend was probably caused by past disturbance of the original vegetation resulting in a succession of secondary vegetation. In addition, the analysis of species population structure indicated that some tree species had abnormal population structure with no or few individuals at lower size classes. Moreover, assessment of regeneration status on the basis of age classes indicated that significant proportion of woody species were represented by few or no seedlings, entailing that they were under threat. Substantial numbers of forest species were found to have irregular population structure and are in reduced regeneration status. To prevent local extinction of these species, present efforts of nursery establishment and plantation of indigenous species in the exclosures should be strengthened and extended.


2016 ◽  
Vol 1 (1) ◽  
pp. 1-12
Author(s):  
Josiclêda Domiciano Galvíncio ◽  
Rejane Magalhães de Mendonça Pimentel

Typical vegetation of arid environments consists of few dominant species highly threatened by climate change. Jurema preta (Mimosa tenuiflora (Willd.) Poiret) is one of these successful species that now is dominant in extensive semiarid areas in the world. The development of a simple bioclimatic model using climate change scenarios based on optimistic and pessimistic predictions of the Intergovernmental Panel on Climate Change (IPCC) shown as a simple tool to predict possible responses of dominant species under dry land conditions and low functional biodiversity. The simple bioclimatic model proved satisfactory in creating climate change scenarios and impacts on the canopy temperature of Jurema preta in semiarid Brazil. The bioclimatic model was efficient to obtain spatially relevant estimations of air temperature from determinations of the surface temperature using satellite images. The model determined that the average difference of 5oC between the air temperature and the leaf temperature for Jurema preta, and an increase of 3oC in air temperature, promote an increase of 2oC in leaf temperature. It leads to disturbances in vital physiological mechanisms in the leaf, mainly the photosynthesis and efficient use of water.


2011 ◽  
Vol 50 (No. 10) ◽  
pp. 463-469 ◽  
Author(s):  
J. Akhter ◽  
K. Mahmood ◽  
K.A. Malik ◽  
A. Mardan ◽  
M. Ahmad ◽  
...  

The hydrogel amendments may improve seedling growth and establishment by increasing water retention capacity of soils and regulating the plants available water supplies, particularly under arid environments. The effects of different levels of a locally prepared hydrogel were studied on the moisture properties of sandy loam and loam soils (fine-loamy, mixed, hyperthermic Typic Haplargids, USDA, Luvic Yermosol, FAO) and on growth response of three plant species, viz. barley (Hordeum vulgare L.), wheat (Triticum aestivum L.) and chickpea (Cicer arietinum L.). Water absorption by gel was rapid and highest in distilled water and was inhibited by an increase in water salinity. The addition of 0.1, 0.2 and 0.3% hydrogel increased the moisture retention (θr) at field capacity linearly (r = 0.988) and thus the amount of plant available water significantly in both sandy loam and loam soils compared to the untreated soils. Seed germination of wheat and barley was not affected but seedling growth of both species was improved by the gel amendment. In loam soil, seed germination of chickpea was higher with 0.2% gel and seedling growth increased with increase in gel level compared with control conditions. The hydrogel amendment caused a delay by 4–5 days in wilting of seedlings grown in both soils compared with control conditions. The hydrogel amendment was effective in improving soil moisture availability and thus increased plant establishment. However, the varied responses of plant species in sandy loam and loam soils warrant further studies on the behaviour of different soil types with gel amendments.


2014 ◽  
Vol 13 (2) ◽  
pp. 182-189
Author(s):  
Lauren E. Fletcher ◽  
Julio E. Valdivia-Silva ◽  
Saul Perez-Montaño ◽  
Renee M. Condori-Apaza ◽  
Catharine A. Conley ◽  
...  

AbstractThe objective of this work was to develop a field method for the determination of labile organic carbon in hyper-arid desert soils. Industry standard methods rely on expensive analytical equipment that are not possible to take into the field, while scientific challenges require fast turn-around of large numbers of samples in order to characterize the soils throughout this region. Here we present a method utilizing acid-hydrolysis extraction of the labile fraction of organic carbon followed by potassium permanganate oxidation, which provides a quick and inexpensive approach to investigate samples in the field. Strict reagent standardization and calibration steps within this method allowed the determination of very low levels of organic carbon in hyper-arid soils, in particular, with results similar to those determined by the alternative methods of Calcination and Pyrolysis–Gas Chromatography–Mass Spectrometry. Field testing of this protocol increased the understanding of the role of organic materials in hyper-arid environments and allowed real-time, strategic decision making for planning for more detailed laboratory-based analysis.


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