Impacts of Riparian Forest Removal on Palauan Streams
Article first published online: 17 JUL 2008
© 2008 by The Association for Tropical Biology and Conservation No claim to original US government works
Volume 40, Issue 6, pages 666–675, November 2008
How to Cite
MacKenzie, R. A. (2008), Impacts of Riparian Forest Removal on Palauan Streams. Biotropica, 40: 666–675. doi: 10.1111/j.1744-7429.2008.00433.x
- Issue published online: 17 OCT 2008
- Article first published online: 17 JUL 2008
- Received 12 October 2007; Revision accepted 5 May 2008.
- benthic algae;
- chlorophyll a;
- net daily metabolism;
- nutrient concentrations;
- total suspended sediments;
- tropical streams
The 2006 completion of the circum-island Compact Road on the island of Babeldaob in the Republic of Palau resulted in several deforested stream reaches with modified stream channels. To determine the impacts of deforestation and road construction, various ecosystem parameters were compared between road-impacted reaches, reforested savanna reaches, and forested reaches. Compared to adjacent forested reaches, road-impacted reaches received significantly more light (0.4 ± 0.1 vs. 87.8 ± 4.1 % light transmittance, respectively), were significantly warmer (25.7 ± 0.1 vs. 26.1 ± 0.1°C, respectively), and received higher nutrient and sediment loads, all of which were attributed to the removal of riparian vegetation and increased surface runoff from the road. These differences were believed to have shifted the benthic algal community in road-impacted reaches from diatoms to filamentous algae with significantly greater chl a biomass (10×) and benthic algal ash free dry mass AFDM (3×) compared to adjacent forested reaches. Savanna-impacted and forested reaches had similar chl a, algal AFDM, and received similar amounts of light. Nutrient and sediment concentrations varied between the two reach types. Results from this study emphasize the need for the maintenance of riparian forests especially with predicted increases in population, development, and deforestation. Future studies are needed to determine effective riparian widths and riparian forest community structure to help resource managers and land owners protect and preserve the many ecosystem services that Palauan streams and watersheds provide.