scholarly journals The Kobresia pygmaea ecosystem of the Tibetan highlands – origin, functioning and degradation of the world’s largest pastoral alpine ecosystem

2017 ◽  
Author(s):  
Georg Miehe ◽  
Per-Marten Schleuss ◽  
Elke Seeber ◽  
Wolfgang Babel ◽  
Tobias Biermann ◽  
...  
Keyword(s):  
Rangeland Management ◽  
Anthropogenic Factors ◽  
High Genetic Diversity ◽  
Alpine Ecosystem ◽  
Reproduction Strategy ◽  
Pasture Degradation ◽  
Key Species ◽  
C Stocks ◽  
Flux Measurements ◽  
Kobresia Pygmaea

AbstractKobresia pastures in the eastern Tibetan highlands occupy 450000 km2 and form the world’s largest pastoral alpine ecosystem. The main constituent is an endemic dwarf sedge, Kobresia pygmaea, which forms a lawn with a durable turf cover anchored by a felty root mat, and occurs from 3000 m to nearly 6000 m a.s.l. The existence and functioning of this unique ecosystem and its turf cover have not yet been explained against a backdrop of natural and anthropogenic factors, and thus its origin, drivers, vulnerability or resilience remain largely unknown. Here we present a review on ecosystem diversity, reproduction and ecology of the key species, pasture health, cycles of carbon (C), water and nutrients, and on the paleo-environment. The methods employed include molecular analysis, grazing exclusion, measurements with micro-lysimeters and gas exchange chambers, 13C and 15N labelling, eddy-covariance flux measurements, remote sensing and atmospheric modelling.The following combination of traits makes Kobresia pygmaea resilient and highly competitive: dwarf habit, predominantly below-ground allocation of photo assimilates, mixed reproduction strategy with both seed production and clonal growth, and high genetic diversity. Growth of Kobresia pastures is co-limited by low rainfall during the short growing season and livestock-mediated nutrient withdrawal. Overstocking has caused pasture degradation and soil deterioration, yet the extent remains debated. In addition, we newly describe natural autocyclic processes of turf erosion initiated through polygonal cracking of the turf cover, and accelerated by soil-dwelling endemic small mammals. The major consequences of the deterioration of the vegetation cover and its turf include: (1) the release of large amounts of C and nutrients and (2) earlier diurnal formation of clouds resulting in (3) decreased surface temperatures with (4) likely consequences for atmospheric circulation on large regional and, possibly global, scales.Paleo-environmental reconstruction, in conjunction with grazing experiments, suggests that the present grazing lawns of Kobresia pygmaea are synanthropic and may have existed since the onset of pastoralism. The traditional migratory rangeland management was sustainable over millennia and possibly still offers the best strategy to conserve, and possibly increase, the C stocks in the Kobresia turf, as well as its importance for climate regulation.

scholarly journals Pasture degradation modifies the water and carbon cycles of the Tibetan highlands

2014 ◽  
Vol 11 (6) ◽  
pp. 8861-8923 ◽  
Author(s):  
W. Babel ◽  
T. Biermann ◽  
H. Coners ◽  
E. Falge ◽  
E. Seeber ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Surface Properties ◽  
Land Surface ◽  
Carbon Allocation ◽  
Carbon Sink ◽  
Plant Cover ◽  
The Tibetan Plateau ◽  
Onset Of Convection ◽  
Pasture Degradation ◽  
Kobresia Pygmaea

Abstract. The Tibetan Plateau has a significant role with regard to atmospheric circulation and the monsoon in particular. Changes between a closed plant cover and open bare soil are one of the striking effects of land use degradation observed with unsustainable range management or climate change, but experiments coupling changes of surface properties and processes with atmospheric feedbacks are rare and have not been undertaken in the world's two largest alpine ecosystems, the alpine steppe and the Kobresia pygmaea pastures of the Tibetan plateau. We coupled measurements of micro-lysimeter, chamber, 13C labeling, and eddy-covariance and combined the observations with land surface and atmospheric models, adapted to the highland conditions. This allowed us to analyze how three degradation stages affect the water and carbon cycle of pastures on the landscape scale within the core region of the Kobresia pygmaea ecosystem. The study revealed that increasing degradation of the Kobresia turf affects carbon allocation and strongly reduces the carbon uptake, compromising the function of Kobresia pastures as a carbon sink. Pasture degradation leads to a shift from transpiration to evaporation while the total sum of evapotranspiration remains unaffected. The results show an earlier onset of convection and cloud generation, likely triggered by enhanced evaporation. Consequently, precipitation starts earlier and clouds decrease the incoming solar radiation. In summary, the changes in surface properties by pasture degradation found on the highland have a~significant influence on larger scales.

scholarly journals Pasture degradation modifies the water and carbon cycles of the Tibetan highlands

2014 ◽  
Vol 11 (23) ◽  
pp. 6633-6656 ◽  
Author(s):  
W. Babel ◽  
T. Biermann ◽  
H. Coners ◽  
E. Falge ◽  
E. Seeber ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Surface Properties ◽  
Land Surface ◽  
Carbon Allocation ◽  
Carbon Sink ◽  
Plant Cover ◽  
The Tibetan Plateau ◽  
Onset Of Convection ◽  
Pasture Degradation ◽  
Kobresia Pygmaea

Abstract. The Tibetan Plateau has a significant role with regard to atmospheric circulation and the monsoon in particular. Changes between a closed plant cover and open bare soil are one of the striking effects of land use degradation observed with unsustainable range management or climate change, but experiments investigating changes of surface properties and processes together with atmospheric feedbacks are rare and have not been undertaken in the world's two largest alpine ecosystems, the alpine steppe and the Kobresia pygmaea pastures of the Tibetan Plateau. We connected measurements of micro-lysimeter, chamber, 13C labelling, and eddy covariance and combined the observations with land surface and atmospheric models, adapted to the highland conditions. This allowed us to analyse how three degradation stages affect the water and carbon cycle of pastures on the landscape scale within the core region of the Kobresia pygmaea ecosystem. The study revealed that increasing degradation of the Kobresia turf affects carbon allocation and strongly reduces the carbon uptake, compromising the function of Kobresia pastures as a carbon sink. Pasture degradation leads to a shift from transpiration to evaporation while a change in the sum of evapotranspiration over a longer period cannot be confirmed. The results show an earlier onset of convection and cloud generation, likely triggered by a shift in evapotranspiration timing when dominated by evaporation. Consequently, precipitation starts earlier and clouds decrease the incoming solar radiation. In summary, the changes in surface properties by pasture degradation found on the highland have a significant influence on larger scales.

scholarly journals The endangered status of Patella ferruginea in a limpet assemblage hotspot (Plane Island: South West Alboran, Mediterranean Sea): Local distribution factors and species abundance

2020 ◽  
Vol 9 (2) ◽  
Author(s):  
Mohammed El Mustapha Kallouche ◽  
Noureddine Benaissa ◽  
Omar Rouane-Hacene ◽  
Mohammed El Amine Soufi ◽  
Mohamed Bouderbala ◽  
...  
Keyword(s):  
Total Population ◽  
Abiotic Factors ◽  
Species Abundance ◽  
Anthropogenic Factors ◽  
South West ◽  
Key Species ◽  
Sea Current ◽  
The Face ◽  
Patella Ferruginea ◽  
Endangered Status

Limpets constitute an important key species in the intertidal zone. The limpets’ assemblage is evaluated in Plane Island (Paloma Island, Algerian West coast) by detailed censuses which were performed in 8 zones in the main island and 9 islets. Results allowed the estimation of a total population of 3993 of the endangered Patella ferruginea (1.78ind/m), 1861 P. rustica (0.82ind/m), and 383 of the blue Mediterranean limpet P. caerulea (0.17 ind/m). The ferruginous limpet distribution around Plane Island was influenced by abiotic factors as hydrodynamics and the sea current direction. Conversely, anthropogenic factors had an important impact despite the island's distance from the mainland. This study finds that in the face of global warming, the island surface will be reduced, however limpets will have an important contribution to the island's areas and its conservation of biodiversity.

scholarly journals The Genetic Structure of Sorocea bonplandii in Southern Brazilian Forest Fragments: AFLP Diversity

2007 ◽  
Vol 56 (1-6) ◽  
pp. 51-58
Author(s):  
A. R. Ruschel ◽  
R. O. Nodari ◽  
B. M. Moerschbacher
Keyword(s):  
Genetic Diversity ◽  
Atlantic Forest ◽  
Sustainable Management ◽  
Genetic Erosion ◽  
Management Plan ◽  
Genetic Distances ◽  
Conservation Strategies ◽  
Forest Fragments ◽  
High Genetic Diversity ◽  
Key Species

Abstract To analyse possible genetic erosion due to fragmentation in the Brazilian Atlantic Forest ecosystem, we investigated the genetic diversity within and among one large and six small populations of one of the key species of this ecosystem, Sorocea bonplandii, using AFLP analyses of 468 plants. Eight primer pairs yielded 299 polymorphic fragments for analysis. S. bonplandii was characterized by an unusually high genetic diversity within the species and also within individual populations, around 94% of the total genetic diversity occurred within populations. Genetic distances between populations were low in spite of extensive fragmentation. Genetic distance was significantly correlated with geographical distances between fragments, but these differences may have existed before fragmentation. Our results have direct implications for sustainable management of S. bonplandii, indicating that conservation strategies might be based on a random sample of trees taken throughout the Atlantic forest. However, the minimum population size required for maintaining the huge genetic diversity of this species is unknown. In order to establish a sustainable management plan for the species, further ecological studies are needed.

scholarly journals Carbon stocks of above- and belowground tree biomass in Kibate Forest around Wonchi Crater Lake, Central Highland of Ethiopia

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254231
Author(s):  
Misganaw Meragiaw ◽  
Zerihun Woldu ◽  
Vegard Martinsen ◽  
Bal Ram Singh
Keyword(s):  
Forest Cover ◽  
Sustainable Forest Management ◽  
Management Practice ◽  
Anthropogenic Factors ◽  
Tree Biomass ◽  
C Stocks ◽  
Central Highland ◽  
The Status ◽  
C Stock ◽  
The Mean

Forests play an important role in the global carbon (C) balance, but their biomass has decreased globally mainly because of deforestation and a reduction in forest cover. However, little is known about the C stock of tree biomass related to environmental factors in the remnant forest patches. Thus, the present study aimed at assessing the status of C stocks of tree biomass using an allometric equation in Kibate Forest (Ethiopia). Sixty–six plots (30×30 m) were laid out at 100 m interval distance along the altitudinal gradients in five transects. The results revealed that the highest C stocks (67.4%) per species were contributed by Juniperus procera, Ilex mitis var. mitis, Nuxia congesta, and Olea europaea subsp. cuspidata. The mean total tree biomass was 91.9 ± 10.01 Mg ha−1. The mean total C stock was 45.9 ± 5.17 Mg ha−1, out of which 38.3 ± 4.31 and 7.7 ± 0.91 Mg ha−1 were stored in above- and belowground C pools, respectively. Anthropogenic factors were negatively associated with the C-stock distribution in the study area. Thus, the status of the C stock of tree biomass related to anthropogenic factors indicates that sustainable forest management practice is needed in the study area to conserve biodiversity and mitigate climate change.

Population status of Adansonia digitata L. and associated species in a different land use type of Quara district, northwest Ethiopia

2019 ◽  
Author(s):  
Melkamu Abere Erku ◽  
Asmamaw Alemu ◽  
Abeje Eshete
Keyword(s):  
Land Use ◽  
Agricultural Land ◽  
Forest Products ◽  
Anthropogenic Factors ◽  
Agricultural Land Use ◽  
Land Use Type ◽  
Population Status ◽  
Adansonia Digitata ◽  
Importance Value Index ◽  
Key Species

Abstract Background Adansonia digitata is one of the most important Non-timber forest products and a key species that have ecological and socio-economic significance in the lowland area of Ethiopia. However, the population of the species is decreasing from time to time due to different natural and anthropogenic factors. The study important to generate information on the current existing population status of Adansonia digitata across three land use types and will provide a scientific recommendation on further management of a species.Methodology About six plots in each forest and agricultural land use type and five plots in homestead were selected randomly from the topography map. Populations of a species were determined using analysis of variance.Results The result showed that homestead and agricultural land use type had higher Adansonia digitata density than forest land use type but statically it was not significantly different. More Adansonia digitata populations were distributed in the middle diameter and height size classes. Conclusion: The study concludes that Adansonia digitata highly associated with Combretum-Terminalia, Ziziphus and Acacia tree species in the study area. This species is dominant and key ecological importance in the woodland vegetation however; Adansonia digitata has a very low importance value index in the study area, so it needs further management and conservation.

scholarly journals Genetic diversity of vector-borne pathogens in spotted and brown hyenas from Namibia and Tanzania relates to ecological conditions rather than host taxonomy

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jürgen Krücken ◽  
Gábor Á. Czirják ◽  
Sabrina Ramünke ◽  
Maria Serocki ◽  
Sonja K. Heinrich ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Phylogenetic Analysis ◽  
Phylogenetic Analyses ◽  
Sub Saharan Africa ◽  
Anthropogenic Factors ◽  
High Genetic Diversity ◽  
Acinonyx Jubatus ◽  
Ecological Conditions ◽  
Vector Borne ◽  
Babesia Lengau

Abstract Background Improved knowledge on vector-borne pathogens in wildlife will help determine their effect on host species at the population and individual level and whether these are affected by anthropogenic factors such as global climate change and landscape changes. Here, samples from brown hyenas (Parahyaena brunnea) from Namibia (BHNA) and spotted hyenas (Crocuta crocuta) from Namibia (SHNA) and Tanzania (SHTZ) were screened for vector-borne pathogens to assess the frequency and genetic diversity of pathogens and the effect of ecological conditions and host taxonomy on this diversity. Methods Tissue samples from BHNA (n = 17), SHNA (n = 19) and SHTZ (n = 25) were analysed by PCRs targeting Anaplasmataceae, Rickettsia spp., piroplasms, specifically Babesia lengau-like piroplasms, Hepatozoidae and filarioids. After sequencing, maximum-likelihood phylogenetic analyses were conducted. Results The relative frequency of Anaplasmataceae was significantly higher in BHNA (82.4%) and SHNA (100.0%) than in SHTZ (32.0%). Only Anaplasma phagocytophilum/platys-like and Anaplasma bovis-like sequences were detected. Rickettsia raoultii was found in one BHNA and three SHTZ. This is the first report of R. raoultii from sub-Saharan Africa. Babesia lengau-like piroplasms were found in 70.6% of BHNA, 88.9% of SHNA and 32.0% of SHTZ, showing higher sequence diversity than B. lengau from South African cheetahs (Acinonyx jubatus). In one SHTZ, a Babesia vogeli-like sequence was identified. Hepatozoon felis-like parasites were identified in 64.7% of BHNA, 36.8% of SHNA and 44.0% of SHTZ. Phylogenetic analysis placed the sequences outside the major H. felis cluster originating from wild and domestic felids. Filarioids were detected in 47.1% of BHNA, 47.4% of SHNA and 36.0% of SHTZ. Phylogenetic analysis revealed high genetic diversity and suggested the presence of several undescribed species. Co-infections were frequently detected in SHNA and BHNA (BHNA median 3 pathogens, range 1–4; SHNA median 3 pathogens, range 2–4) and significantly rarer in SHTZ (median 1, range 0–4, 9 individuals uninfected). Conclusions The frequencies of all pathogens groups were high, and except for Rickettsia, multiple species and genotypes were identified for each pathogen group. Ecological conditions explained pathogen identity and diversity better than host taxonomy. Graphic Abstract

scholarly journals The Kobresia pygmaea ecosystem of the Tibetan highlands – Origin, functioning and degradation of the world's largest pastoral alpine ecosystem

2019 ◽  
Vol 648 ◽  
pp. 754-771 ◽  
Author(s):  
Georg Miehe ◽  
Per-Marten Schleuss ◽  
Elke Seeber ◽  
Wolfgang Babel ◽  
Tobias Biermann ◽  
...  
Keyword(s):  
Alpine Ecosystem ◽  
Kobresia Pygmaea
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