The Desert Biome — A Simple System for Field Investigations of Ecological Principles

Abstract

During the last few years there has been considerable progress in the study of natural ecosystems. However, translation of the basic concepts system ecology into school curriculum is still in its early stages. Therefore the objectives of the present investigation were to study the structure and function of a desert ecosystem, to develop a desert ecology course and to evaluate it. The structure and function of the ecosystems were investigated in the Negev. Typical food chains were studied in two habitats. Laboratory work was carried out to obtain growth curves and oxygen consumption as a function of temperature. Compartment models were constructed to represent energy flow and energy exchange in the ecosystems.

A course in desert ecology was developed to demonstrate the conclusions obtained from the analysis of models. The programme was evaluated on the basis of the following hypotheses: (1) From their own measurements and observations, students will be able to construct a compartment model of energy flow and energy exchange in the ecosystem; (2) By modelling the ecosystem, students will be able to understand the basic common principles in ecosystem energetics, and will be able to apply these principles to new situations; (3) Students will be able to develop a positive attitude toward modelling and system analysis in ecology.