A rapid method for monitoring macrophytic vegetation

Abstract

Studies of terrestrial vegetation during the MECO (IC18-CT98-0270) and MEDCORE (ICA3-CT2002-10003) projects highlighted the requirement for a rapid, cost-effective method of vegetation survey along a time scale that varies according to the nature of the studies being carried out. When time constraints are restrictive, such surveys may be qualitative and therefore highly dependent on the experience and competence of the observer. Reduction of subjectivity may be achieved by quantifying observation, an approach that would however increase time constraints and reduce cost-effectiveness. The sampling and assessment strategy being proposed here is a semi-quantitative approach to determination of relative abundance of species. It retains the low effort-demand of qualitative technique whilst introducing a flexible quantitative aspect that may be incrementally adjusted towards specific requirements. The area of study is stratified into plots enabling comparison of the same general portions of habitat over time. The species present in each plot are recorded enabling frequencies of occurrence for each species to be calculated. This would also enable the derivation of an Index of Distribution for each species being considered. As such, the investigator may not merely detect community change, but would also be aware of the areas in which such change is most pronounced. The method being proposed was tested during studies of the sand dune systems on the beaches southeast of Bocca d’Ombrone in the Maremma Regional Park, Tuscany, Italy during July 2005. The proposed method enabled sampling of the area of study to be completed in less than half the time required in May 2003 in the same area producing results that were largely comparable to those obtained using more labour-intensive methods.