HR: 1340h
AN: H43F-1696    [Abstracts]
TI: Long term dynamic changes in soil organic matter following forest fires
AU: * Tessler, N
EM: naamat@rmh.org.il
AF: Department of Geography and Environmental Studies, University of Haifa, Haifa, 31905, Israel
AU: Greenbaum, N
EM: noamgr@geo.haifa.ac.il
AF: Department of Geography and Environmental Studies, University of Haifa, Haifa, 31905, Israel
AU: Greenbaum, N
EM: noamgr@geo.haifa.ac.il
AF: Department of Natural Resources & Environmental Management, University of Haifa, Haifa, 31905, Israel
AU: Malkinson, D
EM: dmalk@geo.haifa.ac.il
AF: Department of Geography and Environmental Studies, University of Haifa, Haifa, 31905, Israel
AU: Malkinson, D
EM: dmalk@geo.haifa.ac.il
AF: The Golan Research Institute, University of Haifa, Haifa, 31905, Israel
AU: Wittenberg, L
EM: leaw@geo.haifa.ac.il
AF: Department of Geography and Environmental Studies, University of Haifa, Haifa, 31905, Israel
AB: Soil is an important component of the ecological system, providing a substrate for vegetation growth, habitat for animals and a site for regulation of eco-hydrological processes. After a disturbance, such as a forest fire, the soil undergoes changes that have not all been studied yet. Soil organic matter (OM) is one of the fundamental components of soils. After a fire, OM is destroyed and consequently, physical, chemical and biological properties related to OM are altered. Mt. Carmel, Israel, represents a typical Mediterranean ecosystem, with increasing number of forest fires. In the past decades, 9 large fires (> 100 hectare) and more than 350 smaller ones consumed thousand of hectares of natural and planted vegetation. The study is aimed at a) assessing long term rehabilitation processes of soil properties following forest fires; b) defining pedological indices of soil rehabilitation. Research methods included field and laboratory techniques - soil surveys and sampling in the field in addition to chemical analyses of soil properties. Soil survey and sampling were conducted in regions burnt during 1983, 1989, 1999, and 2005 and in non-burnt control areas. Laboratory analyses included: soil texture, organic matter content (OM), electrical conductivity (EC), phosphorus and other nutrients. Recovery rates of soil properties are related to fire severity and might be divided according to their rehabilitation rates (long or short-term processes). During the time scale in which the research was conducted it is apparent that following fires of all severities OM content remained significantly lower compared to the control values. Patterns of phosphorus levels were similar to the observed OM patterns, implying that these two factors are interconnected. Other components, however, such as pH and EC, which are also influenced by OM, exhibit different recovery patterns - pH values increased abruptly after the fire, and recovered within 1-7 years period (depending on fire severity), while the electric connectivity (EC) significantly increased after the fire and exhibited a prolonged decrease. According to our findings, we suggest that the primary impact of fires is mainly in A horizon (soil surface 0-10 cm). OM content plays a key role affecting various nutrients response to the fire and their recovery rates. Thus, in contrast to many studies demonstrating a rapid recovery of the soil system in Mediterranean ecosystems, our findings, based on a 23 years time span, indicates a long term rehabilitation of most soil compounds after forest fires.
DE: 1865 Soils (0486)
SC: Hydrology [H]
MN: 2007 Fall Meeting