Catalogue of field indicators and variables

 

Introduction
Field Data Protocol
Plot Level
Landscape Level

 

Introduction

The main objective of the field work carried out in the frame of GeoRange is to adapt, update and complement existing information in order to assess the current state of mulit-functional Mediterranean rangeland ecosystems based on state variables and indicators. For each site, specific management situations will be considered such as the problem of wildfires in the Ayora site, or the effect of different levels of grazing in Lagadas. However, for reasons of comparability and uniformity, there is a necessity to use a common set of indicators / parameters that will directly or - making use of empirical relationships - indirectly characterise the rangeland resources.

Whereas GeoRange is an applied and user-oriented project at regional scale, it is a necessity to calibrate the parameters employed with field data on a high confidence level. There is a very wide range of parameters that can serve as an indicator for rangelands conditions. However, the major criterion for indicators is whether they can be measured easily and objectively by managers and end-users and derived on adequate spatial scales from RS/Geomatics-approaches with appropriate accuracy. Else all information would be exclusively field-related without opportunities to upscale. Thus, a lean catalogue of indicators is required, employing only as many parameters as necessary in order to adher to the prerequisite of operationality. Consequently, it is most efficient to firstly study a wider range of indicators in only some locations which are characterising the ecological gradients found within landscapes. Susebquently, these measurements can be used to define empirical relationships to relate / calibrate the fewer indicators of the common catalogue assessed at regional scale to the ecological value of ecosystems.

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Field Data Protocol

Plot Level

On the plot level, range conditions and resources will be described on representative and replicated plot-stations that are supposed to represent the present ecosystem diversity and that are arranged according to gradients of driving forces (e.g. grazing pressure, fire event). On this level, ecologists and range managers will proceed a complete or even exhaustive fieldwork and characterise the plots by the following parameters:

Biotic parameters

Plant Community

Structure

• Life forms stratification, height (mean, maximum, per layer)
• Species composition (density, dominance, diversity, rare species)
• Cover [line-intercept method, quadrats]
• Aboveground biomass (among, distribution) [Use of available data, additional measurements by harvesting. Calculation of relationships (Biomass / species-habitat / m2-cover)]
• Necromass (among of dead tissues, distribution, fuel accumulation) [protocol as for biomass]
  

Function

• Photosynthetic activity - LAI [measurement by portable measurement organ]
• Primary productivity [empirical estimation]
• Dynamics, nutrient cycles, and energy flow [estimation<
  
  

Animal Community

• Characterization of biodiversity [estimation and accessory study of bird communities as indicators of total biodiversity [diversity, populations]<
  
  

Physical Parameters

Evaluation of Range Condition (Lagadas and Sardinia Sites)

Evaluation of Wildfire Events (Ayora Site)

 

Landscape Level

On the landscape level, the ecologists and range managers in close collaboration with the specialists in RS/GIS will focus the work only on the ranking estimation of a few indicators that can be derived from RS/Geomatics-approaches. This procedure that is a compromise between spatial extension and spatial detail will allow the wide use of geomatics at a regional scale. The interpretation and evaluation of the estimated parameters will be completed by terrain variables that can be derived from DEM (relief, aspect, slopes, hydrological network, roads, soil erosion potential) and the layers of map information (geology, soil type and depth, site quality, road network) prepared for the local GIS environments.

The fieldwork includes an accurate vegetation mapping and estimation of characteristic and important indicators that represent the main functions of rangelands:

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