Grazing Effects on the Seed Pool of \u3cem\u3eStipa Krylovii\u3c/em\u3e and Its Genetic Diversity in Relationship to the Plant Population on a Typical Steppe Community in Inner Mongolia

Stipa krylovii is an important tufted forage species on the typical steppe in Inner Mongolia and is sensitive to heavy grazing pressure. Vegetative recovery of plant density is dependent on the seed bank, which is a genetic reservoir that supports the vegetative expression of the species thus enhancing its resilience (McCue and Holtsford 1998). The ability of the seed bank to support the Stipa krylovii population is dependent on its size and genetic diversity. Therefore, we conducted a study to determine the effects of heavy grazing pressure on its seed reserves and examine its genetic diversity in relation to surviving plants

Grazing Effects on Genetic Diversity of \u3cem\u3eFestuca Campestris\u3c/em\u3e Rydb. And \u3cem\u3eStipa Grandis\u3c/em\u3e L. On the Native Grasslands in Canada and China, Respectively

Genetic drift or selectively neutral mutation in finite populations may result in genetic diversity within a natural population (Kimura, 1986). Genetic diversity influences the resilience of a species to survive perturbations or adapt to changes in its environment. Grazing by livestock may affect genetic diversity by exerting selection pressure on grazing sensitive species. In this study, we examine the effects of heavy sustained grazing pressure on the genetic diversity of Festuca campestris Rydb. and Stipa grandis L. These species are found on the Canadian Plains and the steppes of Inner Mongolia, respectively. Each is an important forage species that dominates their respective grasslands but decline readily when subjected to heavy grazing pressure

Strategies on Poisonous Plants Problem in China

Poisonous plants are widely distributed on large areas of native grasslands of China, causing livestock poisoning and grassland degradation, which severely impacts the development of animal husbandry. Of the almost 300 poisonous species that are responsible for livestock losses in China, locoweed, drunken horse grass and Langdu cause the greatest impact. Many strategies have been developed to minimise the impact of poisonous plants including the treatment of livestock that have been poisoned, controlling poisonous plants and managing livestock grazing. Both physical and chemical traditional methods are still used to eliminate poisonous plants while biological control using specific insects may eventually be used to control certain species. According to a grassland law, grazing systems (rotational, rest and forbidden grazing) may be applied on dense stands of poisonous plants

Effects of Stocking Rate on the Variability of Ecosystem Productivity in Desert Steppe

Management practices can increase biodiversity and generate corresponding compensatory effects on biomass production, which may reduce inter-annual variability of productivity in some grassland ecosystems. However, it remains unclear how stocking rate influences variability of ecosystem productivity. Four stocking rates were compared in a completely randomized block experiment in the desert steppe of Inner Mongolia, China: non-grazed control (0 sheep/ha/mo), lightly grazed (LG, 0.15 sheep/ha/mo), moderately grazed (MG, 0.30 sheep/ha/mo) and heavily grazed (HG, 0.45 sheep/ha/mo). Aboveground net primary productivity (ANPP) was measured every August for eight consecutive years (2004-2011). ANPP decreased significantly (P \u3c 0.05) with increasing stocking rate. Coefficients of variation for community (CVcomm) in LG and MG were lower than in the control and HG treatments. Coefficients of variation for both species (CVsp) and functional groups (CVPFG) showed logarithmic relationships with relative density (P \u3c 0.05). Thus, both stocking rate and annual precipitation significantly affected the biodiversity and stability of desert steppe in terms of interannual variability of ANPP. As in other grazed systems, our results indicate that grazing management can alter dominant species and functional group components within the grassland community

Effect of Stocking Rate on a \u3cem\u3eStipa Breviflora\u3c/em\u3e Desert Steppe Community of Inner Mongolia

Stocking rate is an important factor in grazing management. The stocking rate defines utilization and ultimately grazing pressure, which in turn affects grassland sustainability. Grassland sustainability is partly defined by its species composition and ultimately by its productivity. These attributes are unique for specific plant communities and the effect of stocking rate must be established for each in order to understand the community response to grazing and to determine its carrying capacity. While some information exists on the effects of stocking rate on livestock production in the Stipa breviflora Griseb. Desert Steppe (Wei et al., 2000), the effects on the plant community are not understood well. This study aimed to determine the effects of stocking rate on the species composition and productivity of that community