ROSELT/OSS Network in the African arid regions
325
Elaboration of support products in decision-making and in
development
The systematic and repeated data collection allows the analysis and processing of
these data, and their translation in terms of ecological describers and/or indicators
for each form of vegetation (or lands cover unit, or type of ecosystem, or agrosystem), and for all types of environmental impacts (natural or caused by men).
Describers and/or indicators originating from lands cover:
- Evolution of each lands cover unit (superficies covered; rates in percentage of the
progressive or regressive evolutions of each unit); models building and validation
(of a type "matrix of transition" for example;
Relationships between the diverse lands cover unit, aiming at demonstrating the
major tendencies of the evolution of the uses of space and vegetal resources; for
example: relationship between the superficies covered by farming systems (more
or less extensive or intensive) and the superficies covered by the integrated
pastoral systems or not, in systems of controlled management of pastoral
resources and corresponding, if need be, to lands and resources traditional
strategies of utilization, or to projects aiming at the restoration of disturbed
ecosystems;
- Evolution of the global level of artificial restoration of a given territory
undergoing environmental monitoring.
Describers and/or indicators built on the floral composition of vegetal communities:
- Evolution of the indexes of floral richness (number of species per surface unit);
- Evolution of the indexes of floral diversity (several indexes can be put forward,
among which only one could be related for example to species already unlisted);
- Relationship between the number of species indicating stability or resilience of
the vegetal system, and the number of species indicating the degradation of the
system, eventually balanced by the indexes of recovery ofthese groups of species.
Describers an/or indicators built on the structure of the vegetation (spontaneous or
cropped):
- Evolution of the rates of recovery of high ligneous (HL), shrubs (LL) and
herbaceous (H) by surface unit and per lands cover;
Evolution of the total standing phytomasses (dry matter and spurred parts) of
high ligneous (HL), of low ligneous (LL) and herbaceous (H) per surface unit
and per lands cover;
Evolution of the rates of recovery at main peaks of vegetation by stratum and by
dominant species;
Evolution of active photosynthetic phytomasses (dry matter production per
surface and time unit) at main vegetation peaks, following the stratum and the
dominant species, for the main lands cover unit;
325
Elaboration of support products in decision-making and in
development
The systematic and repeated data collection allows the analysis and processing of
these data, and their translation in terms of ecological describers and/or indicators
for each form of vegetation (or lands cover unit, or type of ecosystem, or agrosystem), and for all types of environmental impacts (natural or caused by men).
Describers and/or indicators originating from lands cover:
- Evolution of each lands cover unit (superficies covered; rates in percentage of the
progressive or regressive evolutions of each unit); models building and validation
(of a type "matrix of transition" for example;
Relationships between the diverse lands cover unit, aiming at demonstrating the
major tendencies of the evolution of the uses of space and vegetal resources; for
example: relationship between the superficies covered by farming systems (more
or less extensive or intensive) and the superficies covered by the integrated
pastoral systems or not, in systems of controlled management of pastoral
resources and corresponding, if need be, to lands and resources traditional
strategies of utilization, or to projects aiming at the restoration of disturbed
ecosystems;
- Evolution of the global level of artificial restoration of a given territory
undergoing environmental monitoring.
Describers and/or indicators built on the floral composition of vegetal communities:
- Evolution of the indexes of floral richness (number of species per surface unit);
- Evolution of the indexes of floral diversity (several indexes can be put forward,
among which only one could be related for example to species already unlisted);
- Relationship between the number of species indicating stability or resilience of
the vegetal system, and the number of species indicating the degradation of the
system, eventually balanced by the indexes of recovery ofthese groups of species.
Describers an/or indicators built on the structure of the vegetation (spontaneous or
cropped):
- Evolution of the rates of recovery of high ligneous (HL), shrubs (LL) and
herbaceous (H) by surface unit and per lands cover;
Evolution of the total standing phytomasses (dry matter and spurred parts) of
high ligneous (HL), of low ligneous (LL) and herbaceous (H) per surface unit
and per lands cover;
Evolution of the rates of recovery at main peaks of vegetation by stratum and by
dominant species;
Evolution of active photosynthetic phytomasses (dry matter production per
surface and time unit) at main vegetation peaks, following the stratum and the
dominant species, for the main lands cover unit;