The main aim of the monitoring of arthropods in Sierra Nevada is to identify variations in relative abundance of the populations of certain species in oromediterranean and cryomediterranean environments above 2,200 m.
Method and effort
For the monitoring of terrestrial arthropods, census plots were established where the presence/absence and abundance of arthropod taxa being monitored were recorded. Specifically, the 18 plots were distributed throughout different enclaves of the summit area of the massif. The plots were strategically located in terms of altitudinal distribution and orientation (northern and southern exposure). Each plot is visited twice from the second fortnight in July until the end of August.
In these plots, abundance in absolute terms is estimated by direct counts, including scrutiny of the vegetation and the search for specimens hidden under rocks. The dimensions of the plots are variable, usually between 3 and 6 m wide and 50 to 100 m long, depending on the characteristics of the location and on species composition and abundance of the arthropod community included on the list of study species.
This monitoring of high-mountain arthropods is conducted annually.
New, T. R. 1998. Invertebrate surveys for conservation. Oxford University Press. 240 pp.