TY - JOUR
T1 - How does experimental selective timber harvesting affect invertebrate diversity across different spatial scales in subtropical streams?
AU - Rolls, Robert J.
AU - Smolders, Kate E.
AU - Boulton, Andrew J.
AU - Webb, Ashley A.
AU - Sheldon, Fran
N1 - Funding Information:
We thank Aumony Forsyth, Ian Hanson, Rob Lloyd, Geoff Smith and Sandi Smolders for field assistance, and Marti Anderson and Jani Heino for statistical advice. Revisions to this paper were stimulated by comments provided by four referees. This research was funded by Forests NSW and an Australian Postgraduate Award scholarship .
Publisher Copyright:
© 2018 Elsevier Ltd
PY - 2019/3
Y1 - 2019/3
N2 - In forestry, selective timber harvesting best management practices (BMPs) are widely adopted to mitigate the effects of clearfell harvesting on stream ecosystems. However, there have been surprisingly few studies experimentally assessing the effects of selective harvesting on freshwater benthic macroinvertebrate assemblages and how anthropogenic disturbances impact biodiversity across multiple spatial scales. We assessed how selective timber-harvesting BMPs affected alpha and beta diversity of stream macroinvertebrates when measured across three spatial scales – between harvested impact and unharvested control streams, among pools within streams, and among samples within pools. Using a multiple paired, Before-After Control-Impact design of two pairs of streams draining unharvested control and harvested impact catchments, we sampled stream macroinvertebrates bimonthly over two years before and after selective timber harvesting. Effects of selective harvesting varied between ‘impact’ streams and among different spatial scales. At the whole-stream scale, harvesting did not impact either alpha or beta diversity in both pairs of control-impact streams. Within streams, harvesting temporarily reduced beta diversity in streams with increasingly intermittent flow, yet caused brief increases in beta diversity in increasingly permanently flowing streams. At the finest spatial scale, harvesting had transient variable effects on within-pool beta diversity in one pair of experimental streams but not the other. The absence of impacts of selective harvesting on alpha diversity at all three spatial scales, and the only transient impacts on beta diversity suggest that these BMPs are sufficient to allow timber harvesting while simultaneously preserving headwater stream biodiversity. Our study provides a basis for developing monitoring programs to assess the relative impacts and consequences of anthropogenic disturbances on multi-species assemblages across different spatial scales. Our findings suggest fine scale (within-stream) beta diversity may be a more sensitive indicator of catchment disturbances than comparisons of alpha and beta diversity at broader scales among streams.
AB - In forestry, selective timber harvesting best management practices (BMPs) are widely adopted to mitigate the effects of clearfell harvesting on stream ecosystems. However, there have been surprisingly few studies experimentally assessing the effects of selective harvesting on freshwater benthic macroinvertebrate assemblages and how anthropogenic disturbances impact biodiversity across multiple spatial scales. We assessed how selective timber-harvesting BMPs affected alpha and beta diversity of stream macroinvertebrates when measured across three spatial scales – between harvested impact and unharvested control streams, among pools within streams, and among samples within pools. Using a multiple paired, Before-After Control-Impact design of two pairs of streams draining unharvested control and harvested impact catchments, we sampled stream macroinvertebrates bimonthly over two years before and after selective timber harvesting. Effects of selective harvesting varied between ‘impact’ streams and among different spatial scales. At the whole-stream scale, harvesting did not impact either alpha or beta diversity in both pairs of control-impact streams. Within streams, harvesting temporarily reduced beta diversity in streams with increasingly intermittent flow, yet caused brief increases in beta diversity in increasingly permanently flowing streams. At the finest spatial scale, harvesting had transient variable effects on within-pool beta diversity in one pair of experimental streams but not the other. The absence of impacts of selective harvesting on alpha diversity at all three spatial scales, and the only transient impacts on beta diversity suggest that these BMPs are sufficient to allow timber harvesting while simultaneously preserving headwater stream biodiversity. Our study provides a basis for developing monitoring programs to assess the relative impacts and consequences of anthropogenic disturbances on multi-species assemblages across different spatial scales. Our findings suggest fine scale (within-stream) beta diversity may be a more sensitive indicator of catchment disturbances than comparisons of alpha and beta diversity at broader scales among streams.
KW - Alpha diversity
KW - Beta diversity
KW - Biodiversity
KW - Forestry
KW - Headwater stream
KW - Riparian
KW - Selective harvesting
KW - Subtropical
UR - http://www.scopus.com/inward/record.url?scp=85057467718&partnerID=8YFLogxK
UR - http://www.mendeley.com/research/experimental-selective-timber-harvesting-affect-invertebrate-diversity-across-different-spatial-scal
U2 - 10.1016/j.ecolind.2018.11.050
DO - 10.1016/j.ecolind.2018.11.050
M3 - Article
AN - SCOPUS:85057467718
SN - 1470-160X
VL - 98
SP - 723
EP - 735
JO - Ecological Indicators
JF - Ecological Indicators
ER -