Advantages of the point-intercept method for assessing functional diversity in semi-arid areas

摘要: Abstract: Semi-arid areas are particularly susceptible to the loss of biodiversity as a consequence global change. Species functional traits key drivers functioning and resilience ecosystems, thus monitoring trait diversity is urgently needed. The assessment requires quantification species and/or their in field, though there no consensus on best plant-sampling method be used. aim this study was compare performance point-intercept (PT) with two area-based approaches, modified-Whittaker (MW) Dengler (DE) methods, assess semi-arid areas. herbaceous community savanna-like Mediterranean woodland surveyed at extremes regional precipitation gradient (dry wet). Efficiency species/ traits, precision cover estimates, effect metrics computed for eight were compared. Results showed that examined methods differed efficiency quantifying species/traits both sites. With DE method, fewer detected than MW PT which yielded similar values. had higher dominant non-dominant species/traits. It also evenness, mainly wet location, allowed analysis greater number within 80% “dominance” threshold (i.e., representing relative community), critical aspect assessments. In addition, estimates multi-trait well different (either or lower DE) single-trait weighted means (for N-fixing ability flowering onset), dispersion specific leaf area), evenness height onset). spite observed differences among diversity, approach demonstrated important advantages non-destructive, fine-scale areas, where “less dominant” may play role.