Department of Environment and Conservation

FORESTCHECK plans and progress reports

Details

Published on Friday, 28 July 2006 22:16

Report of Progress 2010–2011

The first round of monitoring all 48 FORESTCHECK grids was completed in 2006. The second round of monitoring commenced in 2008 and this report covers the second session of monitoring at the ten Wellington East monitoring grids located in jarrah forest northeast of Collie. These grids were initially established in 2004 and monitored in 2004-05. This report, and previous reports, can be viewed and downloaded from the Department of Environment and Conservation website at www.dec.wa.gov.au .

All the monitoring grids at Wellington East are located in State forest, National park or conservation parks in Dwellingup 4 vegetation complexes within the jarrah north-east ecosystem. Harvested sites were matched to 1996, 1998 and 2000 harvest activities. The range of time since the last fire was 2-8 years, except for one reference grid that was 23 years. Since the initial monitoring sessions in 2004-05, the three grids in stockyard block (FC32 external reference, FC33 shelterwood and FC 34 gap release) had a prescribe burn in spring 2008. The three Bell block grids (FC35 external reference, FC36 shelterwood and FC37 gap release) were burnt by wildfire in December 2005, between the spring and autumn sample sessions of 2004-05. At all grids, forest attributes including forest structure, regeneration stocking and litter loads were measured and species richness and abundances of macrofungi, cryptogams (lichens and bryophytes), invertebrates, terrestrial vertebrates and vascular plants were recorded. In 2010-11 the leaf area index of all 48 grids was also measured.

Knowledge regarding jarrah forest biodiversity and ecology continues to increase as the second round of FORESTCHECK monitoring proceeds. It is also noteworthy that monitoring at Wellington East took place following the driest 18 month period on record from August 2009 through to the end of 2010. During the late summer and autumn of 2011, jarrah forest on the Darling escarpment showed symptoms of severe drought stress with mortality of overstorey and mid-storey trees at scales of tens of hectares. Data collected from FORESTCHECK grids are therefore an important source of objective information that could be used to inform discussion on matters such as the effects of a drying climate on tree health, regeneration and stand growth.

While the results presented here are from a preliminary analysis, highlights from the 2010-11 results and observations from comparisons with data from the same grids in 2004-05 include:

• Mean annual increments for shelterwood grids in Wellington East ranged from 0.30-1.16 m2 ha-1 yr-1 and were similar to those reported for shelterwood grids in Donnelly (jarrah south ecosystem), Wellington 1 (jarrah north ecosystem) and Perth Hills (jarrah north west ecosystem);
• Seedling recruitment at the Stockyard shelterwood grid (FC33) following the 2008 prescribed fire is a significant finding because it demonstrates that the opportunity for recruitment remains open for at least a decade following silvicultural treatment;
• Small wood and twig loads were greater on all grids except the Stockyard shelterwood (FC33) compared to 2005 and may be due to accelerated small branch shedding following the long dry period from 2009-11;
• Leaf area index varied substantially across the FORESTCHECK grids and these variations appear to be independent of the treatments, or largely driven by other factors;
• Across all FORESTCHECK grids, leaf area index was reduced in 2011 compared to 2010;
• Macrofungal species richness was the same at Wellington east in 2011 (240 spp.) and 2005 (241 spp.). However, there was a large species turnover with only 130 species recorded in both sample years.
• The number of lichens recorded in 2010 was markedly lower (43% less) than in 2005;
• Lichen species richness was lowest on all the recently burnt grids in Stockyard block, regardless of treatment;
• Species richness and abundance of plants was lower than in 2004, which is most likely due to an excessively dry year in 2010;
• A large turn over of plant species occurred between 2004 and 2010 and was possibly due to successional trends following fire associated with six of the grids since 2004;
• A decrease in the diversity of invertebrates in 2010-11 indicates a dryer environment compared to that during the 2004-05 sample; Forty seven percent of invertebrate species recorded in 2010-11 were not recorded in 2004-05;
• There is little overall evidence of an effect due to silvicultural treatments on invertebrates;
• In 2010, numbers of individual honeyeaters and mid-storey feeders such as golden whistler and grey shrike thrush were greater than in 2004, but scarlet and western yellow robins decreased, reflecting changes in understory densities following fire;
• Captures of woylies were dramatically lower than in 2004-05 which coincides with a general decline of woylies across their range.
• Common brushtail possum captures were also lower than in 2004-05, but the reason for their decrease in abundance at Wellington East is uncertain as reduced numbers have not been observed at other FORESTCHECK locations;
• and Numbers of mardo in harvested grids had increased markedly at Wellington East compared to 2004-05.

The FORESTCHECK team is to be commended for their commitment to the project. In 2011-12 monitoring is being conducted in grids established in 2005 in the Blackwood Plateau in the Blackwood district and initially monitored in 2005-06.

Read the full  Report of Progress 2010–2011 (PDF 8.1 MB)