Livestock Grazing: Animal and Plant Biodiversity of Shortgrass Steppe and the Relationship to Ecosystem Function

Oikos ◽  
1998 ◽  
Vol 83 (1) ◽  
pp. 65 ◽  
Author(s):  
D. G. Milchunas ◽  
W. K. Lauenroth ◽  
I. C. Burke
2019 ◽  
Author(s):  
Rohan Sachdeva ◽  
Barbara J. Campbell ◽  
John F. Heidelberg

AbstractMicrobes are the Earth’s most numerous organisms and are instrumental in driving major global biological and chemical processes. Microbial activity is a crucial component of all ecosystems, as microbes have the potential to control any major biochemical process. In recent years, considerable strides have been made in describing the community structure,i.e. diversity and abundance, of microbes from the Earth’s major biomes. In virtually all environments studied, a few highly abundant taxa dominate the structure of microbial communities. Still, microbial diversity is high and is concentrated in the less abundant, or rare, fractions of the community,i.e. the “long tail” of the abundance distribution. The relationship between microbial community structure and activity, specifically the role of rare microbes, and its connection to ecosystem function, is not fully understood. We analyzed 12.3 million metagenomic and metatranscriptomic sequence assemblies and their genes from environmental, human, and engineered microbiomes, and show that microbial activity is dominated by rare microbes (96% of total activity) across all measured biomes. Further, rare microbial activity was comprised of traits that are fundamental to ecosystem and organismal health,e.g. biogeochemical cycling and infectious disease. The activity of rare microbes was also tightly coupled to temperature, revealing a link between basic biological processes,e.g. reaction rates, and community activity. Our study provides a broadly applicable and predictable paradigm that implicates rare microbes as the main microbial drivers of ecosystem function and organismal health.


2005 ◽  
Vol 2005 ◽  
pp. 62-62
Author(s):  
A. Waterhouse ◽  
J.P Holland ◽  
J.Milner

Upland livestock systems dominate land use on upland semi-natural habitats of high conservation value. The future is unclear. CAP reform is likely to highlight the poor financial performance of hill livestock, cross compliance may be very light and agri-environmental support for positive management is likely to be limited. There is much debate about management for different objectives. Trends of abandonment of livestock grazing may continue. This paper highlights alternative outcomes of management of semi-natural grasslands and the linked impacts on livestock production.


1963 ◽  
Vol 61 (2) ◽  
pp. 267-274 ◽  
Author(s):  
J. B. Owen ◽  
Jean W. Ingleton

The problems involved in estimating the food intake of the grazing animal are considered and an account is given of studies made on eighteen Clun ewes and six Hampshire × Clun wethers. Results are given from sixty-eight observations on the relationship between food intake and a fraction dissolved in the faeces when a milled sample is left to stand in 0·2N-HCl for 18 hr. Using, in addition, data from grazing ewes subjected to total faeces collection during winter and spring 1959–60 it is concluded that 4 consecutive days of collection give a reasonable estimate of faecal output, and that where similar groups of sheep are grazing on the same pasture at the same time it is unnecessary to convert faeces output data to intake figures in order to compare intake-production relationships between individuals within a group. Where, however, comparisons are to be made between individuals or groups of sheep grazing different pastures at different times then it becomes necessary to allow for differences in food-faeces ratios; for this purpose the dissolved fraction discussed here is likely to prove a useful faecal indicator eliminating many disadvantages of earlier methods and some of the seasonal bias inherent in other indicators at present in use.


2018 ◽  
Vol 40 (1) ◽  
pp. 77 ◽  
Author(s):  
Ping Li ◽  
Joleen C. Hadrich ◽  
Brian E. Robinson ◽  
Yulu Hou ◽  
Yating Dai ◽  
...  

Livestock production has increased in Inner Mongolia, China, despite widespread documentation of grassland degradation. To begin investigating the relationship that produces these trends, we studied farm-level decisions of herder households. We estimated economic enterprise budgets for 15 counties in Inner Mongolia across five ecosystems in 2009 and 2014 by using household survey data. Six counties decreased livestock stocking rates and had improved profit over time. The remaining counties increased their stocking rates over the period studied and profit decreased for all but one county. Livestock operators who reported negative profit over the 5 years were located across ecosystem types and reported a large number of weather shocks that affected grassland availability. Removing the opportunity cost of land and labour from the economic enterprise budgets resulted in a positive profit for all counties, which may explain why herders continue to increase stocking rates with decreased grassland availability over time.


2016 ◽  
Vol 38 (6) ◽  
pp. 523 ◽  
Author(s):  
G. Mutze

Increasing provision of permanent water points has put most Australian pastoral rangelands within grazing distance of sheep, cattle, kangaroos and large feral herbivores, and there is concern that grazing-sensitive native plants will be lost as a result. Proposals have been developed to conserve plant biodiversity by permanently excluding livestock from any areas that are remote from permanent water, or to buy back pastoral properties and remove existing water points to create large reserves. There is, however, little evidence that water-remote areas provide refuge for grazing-sensitive plants, nor consistent evidence of plant biodiversity loss along gradients of increasing livestock grazing pressure in proximity to water. One of the reasons why that evidence might be lacking is that most livestock studies have not considered the grazing impact of sympatric European rabbits, the most widespread and abundant wild herbivore in southern Australia. Numerous studies have shown that rabbit grazing has a major impact on rangeland vegetation and can prevent regeneration at densities which may be too low to be thought important. Plant biodiversity gradients are readily discernible along gradients of rabbit density in livestock-free reserves. Rabbits are therefore likely to be a significant confounding factor when assessing livestock impacts, or possibly the primary cause of observed patterns of plant diversity. If so, attempts to preserve plant biodiversity by removing livestock are destined to fail in rabbit-grazed areas. Public funds for biodiversity conservation in the pastoral zone might be better spent on co-investment with pastoralists for rabbit control on conservatively stocked properties, rather than on restricting pastoral use of land in livestock-free, rabbit-infested reserves.


Author(s):  
Moshe Shachak ◽  
Steward T.A. Pickett

There are many relationships between ecosystem properties and species (Jones and Lawton, 1995) with the potential links described by five hypotheses: 1. The null hypothesis claims that there is no effect of species diversity on ecosystem processes. The following hypotheses imply biological mechanisms. 2. The diversity–stability hypothesis predicts that ecosystem productivity and recovery increase as the number of species increases (Johnson et al. 1996). 3. The rivet hypothesis predicts a threshold in species richness, below which ecosystem function declines steadily and above which changes in species richness are not reflected by changes in ecosystem function (Ehrlich and Ehrlich 1981; Vitousek and Hooper 1993). 4. The redundant species hypothesis states that species loss has little effect on ecosystem processes if the losses are within the same functional group (Walker 1992) 5. The idiosyncratic response hypothesis suggests that as diversity changes so do ecocosystem processes (Lawton 1994, Lawton and Brown 1994). There have been both field and laboratory attempts to test these hypotheses, (Naeem and Li 1998), however, the interpretation and the generality of the results remain contentious (Tilman 1999). A fundamental reason for such uncertainty is that the hypotheses are not driven by a comprehensive theory of the relationship between species properties and ecosystem processes (Tilman et al., 1997). We propose that the foundations for the necessary theory are in models of the distribution of resources and their utilization by organisms. This is because ecosystem processes such as primary production, decomposition, mineralization, and evapotranspiration are dependent on the processing of resources by the species that are producers, consumers, and decomposers. A theory that links the direct participation of species in ecosystem processes may resolve differences among the various hypotheses or identify how they complement each other. From a community perspective, a theory of resource utilization is based on two alternative assumptions: 1. The rate of ecosystem processes is determined by the few species that are most efficient in using and converting resources. For example, in a desert system, dominant species are those that are proficient in using water for biomass production or in converting inorganic matter into organic materials.


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