BugWise

BugWise volunteer, Adrian Pledger. Photo: J Gollan © J Gollan.

About the Martindale project 

Adrian and Meagan Pledger are property owners at Martindale, 18km southwest of Denman in the Upper Hunter. Adrian and Meaghan measured web diversity and abundance in areas that were actively managed (Grassland sites that were slashed and unslashed) as well as a woodland site in the Wollemi National Park.

This project is important because it not only provides insight into the impacts of land clearing on web-building spider communities, but also examines the natural variability of web-builders in relatively unspoilt National Parks—providing important benchmark values for rehabilitation attempts.

Results and Discussion

Surveys were conducted over ten days (February 15, 20, 27, March 3, 20, 22, 31 and April 3, 4 and 26, 2008). The most common web types were W17 in slashed and unslashed grassland, and W32 in National Park sites. A total of 501 webs were counted (115, 120, 266 in slashed, unslashed and national park sites, respectively) and 12 different web types were recorded (5, 3, and 10 in slashed, unslashed and national park sites, respectively). Seven web-types (W9, W10, W12, W21, W22, W27, W30) were unique to national park sites and one web-type (W13) was unique to unslashed grassland. All three web-types found in slashed grassland were common to unslashed and national park sites. While mean diversity and abundance were similar in the two types of grasslands, mean diversity and abundance was much higher at National Park sites (See figures below).

There were clear differences between grassland sites and those in National Parks. This result was evidence that the conversion of native woodland to open pasture reduces both web-building spider diversity and abundance. There were no differences between slashed and unslashed grassland sites.