Modelización en Geografía Física.-Self-organization in patch pattern dynamics along the climatic gradient of the Judean lowland in central Israel

Abstract

ABSTRACT

The role of Self-organization in the formation, evolution and recovery of natural systems from organismic to global scale cannot be over-estimated. Many of these systems represent a type of patch pattern dynamic behavior where patches are created, spread, expanded, aggregated, dissected and dissolved in parallel, forming myriad patterns through their evolution. Self-organization concern the functioning of intrinsic mechanisms which intrinsically regulate pattern changes leading these systems toward order following phases of disturbance or structural transformation (e.g., from herbaceous ecosystem to shrublands). The aim of this paper is to present a new approach of Converging Self-Organization (CSO) coupling between information from geosimulated self-organization and remote sensing data. Due to the scarcity of fully developed spatio-temporal data bases describing the evolution of these patterns from bare ground to full plant' cover, there was developed and implemented an implicit reconstruction technique to air photographs of three sites along a Mediterraneanarid transect. This technique facilitated the extraction of sequences of patch pattern maps that implicitly represent full cycles of vegetation and soil dynamics. Parameterizing patch patterns using measures of fragmentation and aggregation provided representation of the emergent properties of these patterns through their evolution. In parallel there was implemented Cellular Automata technique simulating different modes of self-organized patch pattern dynamics. These different modes concern the representation of different adhessive vegetation growth strategies: proportion of growth through expansión of existing vegetation patches relative to the proportion of growth gained through colonization of individual plants. Matching between the corresponding emergent pattern properties from the reconstructed and from the simulated dynamics served for inferring regarding the mode of functioning of self-organization along the climatic gradient. High diversity of eco-geomorphic conditions characterize ecosystems along the climatic transect. The high similarity between the emergent properties of the reconstructed patch pattern dynamics, both for the different sites along the gradient and between them and those derived from the Cellular Automata, under this diversity of eco-geomorphic conditions suggest the functioning of self-organized behavior. From an eco-geomorphic perspective this convergence may be explained through the functioning of 'Tipping' forming patterns of source and sink areas. Similarity in lithologies would then explain similarities in these patterns which then may facilitate self-organized behavior. Indications for high adhessiveness of patch pattern dynamics together with this self-organized behavior may explain the resilience of landscapes across the climatic gradient to phases of human disturbance and of draughts. Further field work and simulations are needed for validating the preliminary results presented here regarding the functioning of self-organized behavior in patch pattern dynamics across the climatic gradient zone and its affinity to the 'Tipping' effect.