Comparison of data from two vegetation monitoring methods in semi-natural grasslands

被引:29
作者
Carlsson, ALM
Bergfur, J
Milberg, P [1 ]
机构
[1] Linkoping Univ, Dept Biol IFM, Linkoping, Sweden
[2] SLU, Dept Environm Assessment, Uppsala, Sweden
关键词
accuracy; frequency analysis; ordination; permanent plot; precision; Sweden; vegetation monitoring; visual estimation;
D O I
10.1007/s10661-005-6510-8
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
Two vegetation-monitoring methods were compared: subplot frequency analysis (SF) and visual estimation of percentage cover (VE). Two independent observers collected data from two semi-natural, species-rich grasslands on three different occasions during the growth-season. During the last data collection period, survey times were also recorded. The two different data sets from the two methods were compared using partial Redundancy Analyses. The purpose of the comparison was to identify the method that explains most of the relevant variation in biodiversity-monitoring (inter-and intra-site variation), and the variation irrelevant when evaluating data (systematic inter-observer variation and variation due to phenological changes). Compared with VE data, more variation in SF data could be explained by spatial variables, while less variation depended on the observer and time of year surveyed. SF also found more species per plot but took on average five times longer to complete than VE. In conclusion, the different methods are suitable for different purposes: SF is more suitable for purposes demanding high accuracy and high precision, such as long-term biodiversity-monitoring when the identification of small changes has high priority, while VE might be more suitable for a one-time mapping of a large area.
引用
收藏
页码:235 / 248
页数:14
相关论文
共 20 条