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1. Definition
| Name |
GRAZING |
| Brief
definition |
Grazing
is the removal of entire plants or parts of them by herbivores
in order to feed themselves. In rangeland ecosystems, grazing
constitutes the connecting link between primary (plant) and
secondary (animal) production. |
| Unit of measure |
Percent use
(%) |
| Spatial scale |
|
| Temporal scale |
|
2. Position
within the logical framework DPSIR
| Type
of Indicator |
Ecological
factor/driving force. It is a composite indicator including
at least four different parameters: intensity, frequency, season
and selectivity. |
3. Target and
political pertinence
| Objective |
To
evaluate the impact of herbivores, especially domestic animals
on vegetation and other components and processes of rangeland
ecosystems such as soil, flora, fauna, water and nutrient cycles. |
| Importance
with respect to desertification |
Grazing
may cause desertification if irrationally practised. Irrational
grazing is usually associated with excessive numbers of animals
(overgrazing). In reality however irrational grazing is also
applied when the animals are fewer than the grazing capacity
of a particular rangeland, the kind of animals used are unsuitable
and the grazing system applied is inadequate. |
| International
Conventions and agreements |
The UNCCD emphasizes
that in order to combat desertification it must be tackled within
the general framework of actions that promote sustainable development.
Within Agenda 21 overgrazing is relevant to Chapter 11 (Combating
deforestation) and Chapter 18 (Protection of the quality and
supply of freshwater resources: Application of integrated approaches
to the development, management and use of water resources). |
| Secondary objectives
of the indicator |
To evaluate
the response of plants to animal pressure and the mechanisms
that have developed in order to tolerate or withstand this force.
|
4. Methodological
description and basic definitions
| Definitions
and basic concepts |
Grazing
is an indicator of plants’ vulnerability to herbivores.
This vulnerability may be low or high depending on palatability
factors, such as plant morphology, chemical composition and
environmental conditions. On the other hand, grazing is also
associated with animal preference linked to animal factors such
as the particular species or breeds of animal and exemplified
by plant digestibility. |
| Benchmarks
Indication of the values/ranges of value |
In general,
plant species can tolerate up to 50 % use of their aboveground
parts without being harmed. However, this percentage may be
higher is some species (e.g. prostrate herbs, stump sprouting
woody plants) or lower in some others (e.g. tall herbs, non
sprouting woody plants). |
| Methods
of measurement |
Percent
use is measured on the basis of the remaining parts of a particular
plant or a community after defoliation. Paired plots are usually
established, one protected from grazing and the other freely
grazed. The formula to be applied is the following:
[(A-B)/A]*100
Where A is the weight
of the protected plot and B is the weight of the grazed plot.
|
| Limits of the
indicator |
Grazing does
not cause desertification unless it is irrational and combined
with wildfires. Even heavy grazing may be beneficial to a rangeland
if it is not applied for a long time and in very dry years. |
| Linkages with
other indicators |
Grazing is
an umbrella indicator, broader than grazing
intensity, grazing impact and grazing
control. It is linked with several other indicators related
with climate, soil, vegetation, fire and land use as well as
with livestock husbandry. |
5. Evaluation
of data needs and availability
| Data
required to calculate the indicator |
Data
relative to forage production and utilisation, vegetation composition
and kind of livestock. |
| Data sources |
Vegetation
and biomass inventories, climatic and vegetation maps, research
reports, published information. |
| Availability
of data from national and international sources |
National
and international research institutes, Agriculture Universities,
extension services. |
6. Institutions
that have participated in developing the indicator
| Main
institutions responsible |
Department
of Range Science and Wildlife-Freshwater Fisheries, Aristotle
University of Thessaloniki, Greece |
| Other
contributing organizations |
CNR
and University of Sassari, Sardinia |
7. Additional
information
| Bibliography
|
Papanastasis,
V.P. and D. Peter (eds) 1998. Ecological Basis of Livestock
Grazing in Mediterranean Ecosystems. Proc. Inter. Workshop,
Thessaloniki October 23-25, 1997. European Commission, EUR 18308,
Luxembourg, 350 pp. |
| Other references |
Papanastasis,
V.P., S. Kyriakakis and G. Kazakis. 2002. Plant diversity in
relation to overgrazing and burning in mountain Mediterranean
ecosystems. J. Mediterranean Ecology: (2-3): 53-63
Pulina G., M. d’
Angelo, S. Mardau, C. Zucca and G. Enne.1998. Indicators of
land use intensity in agropastoral ecosystems. Indicators
for assessing desertification in the Mediterranean. Proceedings
of the International Seminar held in Porto Torres, Italy 18-20
September, 1998.
|
| Contacts Name
and address |
Prof. Vasilios P. Papanastasis
Laboratory of Rangeland
Ecology, Faculty of Forestry and Natural Environment, Aristotle
University, 54 124 Thessaloniki, Greece.
Tel:+30 2310 998933
Fax:+30 2310 992721
E-mail: vpapan@for.auth.gr
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