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SSS10.1

The impact of grazing on land degradation: Identifying problems, causes and solutions from a global perspective
Convener: Manuel Pulido  | Co-Conveners: Michael Vrahnakis , Valdemir Antoneli , Warwick Badgery , Isabel Miralles Mellado , Ali El-Keblawy 
For millennia animals shaped the grazing landscapes, which occupy more than 25% of world’s land surface, affecting the soil, vegetation, and water and fauna characteristics. Nowadays, grazing is an economic activity carried out in a wide range of ecosystems, from arid to humid areas, and societies of the world, from the poorest to the most developed countries. Most of ecosystems show common problems although there are many driving forces depending on socioeconomic factors that lead the occurrence of land degradation processes.

A mismanagement of livestock is accepted as the main cause of land degradation in rangelands, particularly when stocking rates are not matched to land capability. The occurrence of land degradation processes has been traditionally studied as a consequence of exceeding the optimum number of livestock but there are many more problems than only overgrazing. The abandonment of pastoralism, for example, is reducing biodiversity and increasing the risk of wild fires in many ecosystems. Weed invasion (e.g. trees invading in northern Australia) and climate change impacts on vegetation should be also considered.

The land management of privately-owned farms or communal grazing lands is influenced by current and past social, political and economic factors. The low profitability of animal products along with a strong demographic pressure in the poorest countries, contrasts with the pressure in the form of subsidies and taxes that is leading to both intensification and extensification problems in the most developed societies. Furthermore, a new climate scenario leading to lower soil water availability will be presumably a common feature.

Problems such as the reduction of the soil quality, a lower production (forage and animal) or the increasing of GHG emissions such as neither methane nor nitrous oxide have been reported so far by many authors but different research approaches are needed. Nevertheless, more attention on spatial aspects of grazing is still needed, particularly in those that evolve techniques such as the use of GPS aiming to monitor the spatial movement of the animals or remote sensing to quantify tree clearing.

The solutions proposed to ameliorate rangelands or grasslands must be also deeply analysed; while there are common problems they need local approaches. Solutions such as the reduction of stocking rates, conversion of forest into silvopastoralism areas or the use of many different livestock management system should be tested where they are relevant in the world. Other remaining questions about how to manage abandoned areas or how recover degraded rangelands, e.g. fencing exclusion, should also be addressed at different scales.

The purpose of the Session is to collect contributions dealing with the occurrence of land degradation processes caused by a land mismanagement, that can be useful to identify problems and their driving forces, as well as to propose alternatives and solutions that are helpful for farmers, stakeholders or for the environment’s health. Participants in the previous session (SSS9.3/BG2.15/GM4.6/HS10.13EGU 2015) about grazing presented in the Special Issue of Land Degradation & Development journal are also invited to participate in order to share their new advances.