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[en] The present study elaborates the results of the first phytosociological research conducted in the Shigar valley, Karakorum Mountains along with posed natural and human made threats. Random stratified sampling method was used in order to collect phytosociological data. During field trips carried out in 2013-2016, 14 localities and 35 altitudinal transects were sampled in the elevation range of 2200-4700m. The plant communities were determined, and the plant taxa were analyzed against environmental variables using computer packages. Each community was analyzed for potential threats by point scaling (1-3) method. In all 345 species were recorded belonging to 206 genera and 63 families including few endemic and rare taxa such as Aconitum violaceum var. weilerei, Asperula oppositifolia subsp. baltistanica, Festuca hartmannii, Anaphalis chitralensis, Hedysarum falconeri, Pedicularis staintonii, Clematis alpine var. sibirica and Pyrola rotundifolia subsp. karakoramica. Species richness was observed at middle elevations. Three communities were recognized along altitude with prevailed dry slopes residing maximum thermophilous and petrophilous species. The main controlling factors of species composition and distribution pattern along elevation were soil moisture, substrate, aspect and elevation. Grazing, uprooting, trampling and cutting were recognized as the major degradation processes of the vegetation. The mountainous vegetation of the study area possesses substantial plant biological diversity with unique assemblage with elevation. Several anthropo-natural threats were observed mostly connected with direct habitat fragmentation triggering rapid decline in vegetation cover. Nevertheless, the grazing, uprooting and cutting were potential and destructive threats for local plant biota which demand prompt conservation plans.
[en] While overgrazing is often blamed for environmental degradation, there is clear evidence that livestock are not inherently damaging to rangelands or farming landscapes, and, in fact, may be required for their sustained health and profitability. Moderate to heavy grazing has, in some cases created highly resilient and ecologically sound systems while under-grazing has resulted in dense woody growth and reduced species diversity. Conversion of rangelands into intensive crop/fodder production has also led to progressive loss of diversity, species connectivity and ability to recover. Well-managed livestock in either a grassland or mixed crop/livestock system offer a highly efficient method of increasing the production of high quality food with minimal environmental impact. Although an ecological case can be established for the continued use of livestock in degrading landscapes, the reality is, livestock will only be grazed responsibly if the owner receives a benefit from the process. Importantly, by providing a potentially profitable option, the revegetation of degraded or partly degraded landscapes may take place through the expenditure of private rather than public funding. Given the vastness of the landscapes in question and the urban priorities in the expenditure of public funds, significant progress is only likely if profitable solutions are available. This use of livestock may or may not contribute to the return of the landscape to its original state. In some cases stable vegetation that provides some of the functional benefits of the original landscape, combined with the productive benefits of a profitable livestock system may be the best option available. This then provides an opportunity to design a landscape based on a range of predetermined objectives which include both profit and ecosystem services. For example, in Western Australia, the revegetation of 10% of the 1 million ha of saline land with halophytic shrubs and salt tolerant forage has resulted in a system that provides valuable out of season feed for livestock, slows or reverses the elevation of saline groundwater tables and reduces salt and sediment run-off into waterways. Meeting the nutritional and environmental requirements of livestock grazing degraded environments will always be a challenge. Both over- and under-grazing are likely to result in a loss of species diversity. As livestock have the ability to select plants with higher digestibility, adequate nitrogen (crude protein) and low or manageable anti nutritional compounds, loss of diversity will be accompanied by a decline in nutritive value and palatability and reduced ability to deal with toxins. In the case of over-grazing the decrease in diversity and nutritive value will be accompanied with a decrease in feed availability. Management of livestock, vegetation and the interaction between the two is critical for productive grazing of such fragile environments. Where loss of diversity is a consequence of previous over-grazing, complementary feeding can improve feed intake, feed conversion efficiency and therefore productive potential. Examples include the provision of energy supplements to improve the utilisation of plants that contain high levels of non-protein nitrogen or to facilitate the breakdown of anti-nutritional compounds in the forage. Similar strategies can be applied to revegetation with selective planting to complement the composition and availability of other feed resources. Where revegetation is an option, there will be additional benefits in assessing the plant options for palatability, nutritive value, anti-nutritional properties, shelter and possible medicinal properties as well as selected ecosystem benefits. These do not need to be long-term and expensive plant breeding projects but may be well designed and localised screening programs based on indigenous plant species with known natural advantages. For reasons described above revegetation should complement rather than replace existing feed resources. Strategies to improve the intake and utilisation of forages in degraded environments have the potential to induce further degradation if not accompanied by improved grazing management. Technologies are now available that allow remote monitoring of livestock condition and behaviour. This type of direct information provides incentive and opportunity for livestock managers to tactically manipulate feeding and production. For example, monitoring change in both livestock and forage are grazing management options. While monitoring feed supply is the more traditional method advocated in high input grazing, more information and control may be available from direct livestock monitoring in the more extensive, low input systems that characterise degraded landscapes. Livestock will begin to lose weight long before feed supply is exhausted and live weight change may provide information on both available biomass and diversity of feed sources. Similarly, animal behaviours, such as time spent walking, grazing and feeding are related to feed supply and diversity. Grazing and feeding behaviour can be further assessed with the use of stable isotope techniques applied to feed and water intake. These techniques have the potential to optimise the combination of livestock production and ecological stability that will be required for the long-term productive use and revegetation of degraded landscapes. (author)
[en] The perfectly matched layer (PML) is an efficient absorbing boundary condition for mitigating undesired reflections in seismic wave modelling. However, the performance of the conventional split-field PML (S-PML) is severely reduced at grazing incidence. Very low frequency waves and evanescent waves can also cause spurious reflections on the PML interface. Such problems could be circumvented by using the complex-frequency-shifted (CFS) stretching tensor in the PML. However, it is difficult to adopt the CFS stretching tensor in the S-PML. A matched Z-transform PML (MZT-PML) technique applied in electromagnetic modelling results in a complete unsplit-field form. In this paper, we show that the MZT-PML can easily implement the CFS stretching tensor and be adopted for elastic wave finite-difference time-domain modelling. The numerical tests in an elongated model illustrate that the complex-frequency-shifted matched Z-transform perfectly matched layer (CFS MZT-PML) can substantially improve performance by eliminating the spurious reflections at grazing incidence. The numerical stability of the CFS MZT-PML is verified by long time computation of the total energy. Also, we conduct a numerical test in a two-layer heterogeneous model showing that the CFS MZT-PML can also be used to simulate efficiently the wave propagation in more complex structures. (paper)
[en] Near infrared (NIR) spectroscopy is an analytical technique measuring light absorption in the 780-2 500 nm region which is closely related to important chemical bonds (OH, NH and CH). NIR can be used to measure many nutritionally important constituents of concentrate and forage feeds, and from NIR spectra of faeces (i.e. dung) many constituents of the diet of grazing livestock. NIR depends on the development, in representative sets of samples, of mathematical relationships (calibration equations) between spectra and the constituents or attributes measured by conventional chemistry, and then application of these calibrations to estimate the constituents in unknown samples. These NIR calibration equations tend to be specific to the circumstances of the data used for their development. Application of NIR technology to livestock nutrition allows rapid, routine and economical analysis of feedstuffs and ingredients for compounded diets or supplements, thus improving stockfeed manufacture. Also NIR analysis of faeces allows estimation of the diet selected by grazing livestock and in small holder farming systems; this is not possible with any other technology. However, NIR instrumentation requires substantial capital investment, and considerable technical skills are required to develop and maintain calibration equations. Application of NIR technology allows established knowledge of the science of animal nutrition to be readily and objectively applied to improve productivity and cost-effectiveness of livestock production systems. Widespread use of this technology in developing countries would greatly improve quality control in manufacturing livestock feeds and application of existing nutritional knowledge to increase productivity and cost-effectiveness of livestock production. (author)
[en] Highlights: • Dehesas' sustainability is endangered by low profitability and dependence on subsidies. • Current management can jeopardize the maintenance and persistence of dehesa farms. • Specific tools are needed so that farm managers can assess sustainability in an easy and reliable way. • Delphi method has been used to design a set of sustainability indicators adapted to dehesas. • Indicators were selected based on consensus and representativeness regarding sustainability pillars. This paper provides a list of specific indicators that will allow the managers of dehesa farms to assess their sustainability in an easy and reliable way. To this end a Delphi analysis has been carried out with a group of experts in agroforestry systems and sustainability. A total of 30 experts from public institutions, farming, research bodies, environmental and rural development associations, agricultural organizations and companies took part in the study which intended to design a set of sustainability indicators adapted to dehesa agroforestry systems. The experts scored 83 original indicators related to the basic pillars of sustainability (environmental, social and economic) through a two-round procedure. Finally, 24 indicators were selected based on their importance and the consensus achieved. From an environmental point of view, and in line with its significance for dehesa ecosystems, it has been observed that “Stocking rate” is the indicator with greater relevance. Within the economic pillar, “Farm profitability” is the most important indicator, while regarding the technical indicators “Percentage of animal diet based on grazing” is the one that got the highest score. Finally, the “Degree of job satisfaction” and the “Generational renewal” were the most relevant labor indicators. It is considered that the Delphi approach used in this research settles some of the flaws of other sustainability models, such as the adaptation to the system to be studied and the involvement of stakeholders in the design.
[en] The behaviour of simple predator-prey systems is well-known and was exploited to enable some general conclusions to be made about the stability of and productivity in extensive herbivore-plant grazing systems. The techniques employed were mainly graphical and, hence, lacked the mathematical bite for a full analytical discussion of the influencing parameters to be made. This paper attempts to remedy this deficiency. Then it turns to the more difficult problem when spatio-temporal variations are considered. The first part provides an opportunity to illustrate the occurrence of Hopf bifurcation and the appearance of oscillatory modes, the second part allows some interesting wave phenomena to be studied. 6 refs, 2 figs
[en] Mudumalai is biologically rich with a wealth of plant and animal life. Increasing human numbers and current patterns of non-timber forest product, fodder and fuelwood extraction threaten the integrity of the ecosystem. Change in management of the protected areas that include the Mudumalai region is needed. In particular, policies relating to grazing and basic energy requirements need to be reexamined. At the same time, mechanisms must be developed to increase rural incomes using means other than exploitation of natural resources. 7 refs., 3 tabs
[en] The Western Himalayan alpines are among the most diverse ecological locations having diverse vegetation and provide a wide range of ecosystem services. The complex and dynamic Deosai Plateau is the World’s 2nd highest plateau with an average elevation of 4500m. Current study was designed to investigate floristic diversity, phytosociological attributes, endemism and conservation status of flora of Deosai National Park, North Pakistan. Vegetation sampling was carried out by using random sampling through quadrat method at selected sites. A total of 8 plant communities were recorded from the area. The Floristic composition of present study consisted of 132 species belonging to 101 Genera and 41 families. Hemicryptophytes were recorded as the dominant life form followed by geophytes and Therophytes whereas Leptophylls and Nanophylls were dominant leaf spectra. The average value of Shannon diversity was calculated as 1.383 whereas Simpson diversity was 0.447. The calculated values of Evenness and richness were 0.882 and 1.185 respectively whereas the average maturity index was 30.27. A total of 63 plants species were found to be threatened having very low (<1%) importance values with 4 species recorded as critically endangered and endangered. Phytogeographic investigations revealed that 41 plant species (33%) were endemic to the Whole Himalayas, 18 species (14%) Endemic to Western Himalayas, 27 plants (22%) as tropical Asian and 34 plant species (27%) recorded as cosmopolitan. Principal component analyses (PCA) revealed Moisture and altitude as the key factors governing the species composition and community structure in the study area. Grazing pressure was observed as a major threat to the palatable species. It is recommended to extensively explore the population dynamics of endemic species as well as the spread of invasive species in DNP with the focus to conserve the precious threatened flora. (author)
[en] Highlights: • We monitored intensively and sustainably managed soils to month-long drought and flood events. • Bacterial communities in sustainably managed soils contained less rapidly-growing taxa. • Only intensively-managed soils were affected by drought. • Opportunism and stress-tolerance are key traits shaping the bacterial community during recovery. • The response of several taxa to precipitation depended on land management. Increasing climatic and anthropogenic pressures on soil ecosystems are expected to create a global patchwork of disturbance scenarios. Some regions will be strongly impacted by climate change, others by agricultural intensification, and others by both. Soil microbial communities are integral components of terrestrial ecosystems, but their responses to multiple perturbations are poorly understood. Here, we exposed soils from sustainably- or intensively-managed grasslands in an agro-silvo-pastoral oak woodland to month-long intensified drought and flood simulation treatments in a controlled mesocosm setting. We monitored the response of the bacterial communities at the end of one month as well as during the following month of recovery. The communities in sustainably-managed plots under all precipitation regimes were richer and more diverse than those in intensively-managed plots, and contained a lower proportion of rapidly-growing taxa. Soils from both land managements exhibited changes in bacterial community composition in response to flooding, but only intensively-managed soils were affected by drought. The ecologies of bacteria favored by both drought and flood point to both opportunism and stress tolerance as key traits shaping the community following disturbance. Finally, the response of several taxa (i.e. Chloracidobacteria RB41, Janthinobacterium sp.) to precipitation depended on land management, suggesting that the community itself affected individual disturbance responses. Our findings provide an in-depth view of the complexity of soil bacterial community responses to climatic and anthropogenic pressures in time, and highlight the potential of these stressors to have multiplicative effects on the soil biota.
[en] Highlights: • Poverty and pasture deterioration are widespread in Mongolian pastoral systems. • Interacting climate, root and livestock dynamics were modelled in a case study. • Grazing can significantly reduce root biomass (− 30% after 20 years) but not deplete it. • Competition between herders could trap the smallest ones in poverty. • Competition for forage seems as problematic as climate shocks for certain herders. The interplay of livestock density dependence drivers and climate hazards is thought to cause pasture deterioration and poverty in Mongolian pastoral systems. We assessed their relative weights in a system of the Gobi exposed to high rainfall variability and harsh winters, which suggests that climate is the main system's driver. In this aim we modelled how interacting plant and livestock renewal dynamics impact herder performances, under the influence of climate. Plant dynamics was studied through an underground biomass sub-model because local pastures are dominated by perennial species. This approach enabled us studying pastoral issues in a holistic way, by integrating plant underground organs, livestock populations, herder income, and climate drivers. Models described that current grazing practices can significantly reduce underground biomass (− 30% after 20 years), but not entirely deplete it. They also showed that competition between herders could trap the smallest ones in poverty, by preventing the growth of their herds. This competition operates through density dependent factors affecting livestock productivity and vulnerability to climate shocks. This competition effect is all the more important since small herders could grow their herd and escape poverty if they were alone in the system. This result shows that density dependent factors could significantly impact herder performances and suggests that forage resource allocation is a driver as powerful as climate, even in the local harsh bioclimatic configuration of the Mongolian Gobi.