doi: 10.1098/rstb.2011.0049, 3292-3302366 2011 Phil. Trans. R. Soc. B

Valerie Kapos, Glen Reynolds, Waidi Sinun, Jake L. Snaddon and Edgar C. TurnerRobert M. Ewers, Raphael K. Didham, Lenore Fahrig, Gonalo Ferraz, Andy Hector, Robert D. Holt, Altered Forest Ecosystems ProjectA large-scale forest fragmentation experiment: the Stability of

Referenceshttp://rstb.royalsocietypublishing.org/content/366/1582/3292.full.html#ref-list-1

This article cites 41 articles, 7 of which can be accessed free

Email alerting service hereright-hand corner of the article or click Receive free email alerts when new articles cite this article - sign up in the box at the top

http://rstb.royalsocietypublishing.org/subscriptions go to: Phil. Trans. R. Soc. BTo subscribe to

This journal is 2011 The Royal Society

on October 17, 2011rstb.royalsocietypublishing.orgDownloaded from

http://rstb.royalsocietypublishing.org/content/366/1582/3292.full.html#ref-list-1http://rstb.royalsocietypublishing.org/cgi/alerts/ctalert?alertType=citedby&addAlert=cited_by&saveAlert=no&cited_by_criteria_resid=royptb;366/1582/3292&return_type=article&return_url=http://rstb.royalsocietypublishing.org/content/366/1582/3292.full.pdfhttp://rstb.royalsocietypublishing.org/subscriptionshttp://rstb.royalsocietypublishing.org/

on October 17, 2011rstb.royalsocietypublishing.orgDownloaded from

Phil. Trans. R. Soc. B (2011) 366, 32923302

doi:10.1098/rstb.2011.0049

Research

* Autho

One conAsian ra

A large-scale forest fragmentationexperiment: the Stability of Altered

Forest Ecosystems ProjectRobert M. Ewers1,*, Raphael K. Didham2,3,4, Lenore Fahrig5,

Goncalo Ferraz6,7, Andy Hector8, Robert D. Holt9, Valerie Kapos10,11,

Glen Reynolds12, Waidi Sinun13, Jake L. Snaddon8,11

and Edgar C. Turner1,11

1Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot,Berkshire SL5 7PY, UK

2School of Animal Biology, The University of Western Australia, 35 Stirling Highway, Crawley,Western Australia 6009, Australia

3CSIRO Ecosystem Services, Centre for Environment and Life Sciences, Underwood Avenue,Floreat, Western Australia 6014, Australia

4School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, New Zealand5Ottawa-Carleton Institute of Biology, Carleton University, Ottawa, Ontario, Canada K1S 5B6

6Biological Dynamics of Forest Fragments Project, Smithsonian Tropical Research Institute/InstitutoNacional de Pesquisas da Amazonia, 69011 Manaus AM, Brazil

7Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Republic of Panama8Institute of Evolutionary Biology and Environmental Studies, University of Zurich,

Winterthurerstrasse 190, 8057 Zurich, Switzerland9Department of Biology, University of Florida, 111 Bartram, PO Box 118525,

Gainsville, FL 32611, USA10United Nations Environmental Programme (UNEP), World Conservation Monitoring Centre

(WCMW), 219 Huntingdon Road, Cambridge CB3 0DL, UK11Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK

12The Royal Society South East Asia Rainforest Research Programme (SEARRP),Danum Valley Field Centre, PO Box 60282, Lahad Datu, Sabah 91112, Malaysia13Conservation and Environmental Management Division, Yayasan Sabah Group,

Menara Tun Mustapha, Kota Kinabalu, Sabah 88817, Malaysia

Opportunities to conduct large-scale field experiments are rare, but provide a unique opportunity toreveal the complex processes that operate within natural ecosystems. Here, we review the design ofexisting, large-scale forest fragmentation experiments. Based on this review, we develop a design forthe Stability of Altered Forest Ecosystems (SAFE) Project, a new forest fragmentation experimentto be located in the lowland tropical forests of Borneo (Sabah, Malaysia). The SAFE Project representsan advance on existing experiments in that it: (i) allows discrimination of the effects of landscape-levelforest cover from patch-level processes; (ii) is designed to facilitate the unification of a wide rangeof data types on ecological patterns and processes that operate over a wide range of spatial scales;(iii) has greater replication than existing experiments; (iv) incorporates an experimental manipulationof riparian corridors; and (v) embeds the experimentally fragmented landscape within a wider gradientof land-use intensity than do existing projects. The SAFE Project represents an opportunity for ecol-ogists across disciplines to participate in a large initiative designed to generate a broad understanding ofthe ecological impacts of tropical forest modification.

Keywords: Biological Dynamics of Forest Fragments Project; Calling Lake FragmentationExperiment; deforestation; hierarchical sampling design; Savannah River Site Corridor Experiment;

Wog Wog Habitat Fragmentation Experiment

r for correspondence (r.ewers@imperial.ac.uk).

tribution of 16 to a Theme Issue The future of South Eastinforests in a changing landscape and climate.

3292

1. INTRODUCTIONHabitat fragmentation is one of the central issues inconservation biology [1] and has been a source of con-siderable scientific debate since the early application of

This journal is q 2011 The Royal Society

mailto:r.ewers@imperial.ac.ukhttp://rstb.royalsocietypublishing.org/

The SAFE Project R. M. Ewers et al. 3293

on October 17, 2011rstb.royalsocietypublishing.orgDownloaded from

island biogeography theory [2] to terrestrial habitatislands and the design of nature reserves [3,4]. Thesedebates led directly to the establishment of the Mini-mum Critical Size of Ecosystems experiment in theBrazilian Amazon [5,6], now known as the BiologicalDynamics of Forest Fragments Project (BDFFP). Thisvisionary experiment has probably had the single greatestimpact on the general understanding of the ecologicalimpact of forest fragmentation and is routinely cited inthe conservation literature around the world [7,8].

The BDFFP heralded a new approach to the studyof habitat fragmentation, lifting it from one basedalmost solely on observational studies, to one basedon experimentation. The implications for scientificadvancement were tremendous: the use of statisticallybased before-after-control-impact sampling providesmuch stronger inference than observational studies rely-ing on a space-for-time substitution to act as a control[9]. Since the establishment of the BDFFP, there havebeen at least 20 more experimental tests of habitat frag-mentation [10], based mostly in grasslands or fields,but just one of these has matched the BDFFP in termsof the size and number of fragments [11].

Large-scale experiments may be the only way todetermine the responses of forest systems to globalchange [12]. They generate results that are comparableto those arising from observational studies [13], whichensure that large-scale experiments have real-worldpractical relevance. However, the opportunities forlarge-scale, replicated and controlled landscape exper-iments are rare. When they are undertaken, they areinvariably time-consuming and costly to establish, andconsequently there will always be a premium placed onmaximizing the long-term scientific pay-off from thisinitial investment. Consequently, any such experimentsshould address a wide range of ecological questions [10].Moreover, just as the BDFFP was designed to address acentral, policy-relevant issue about reserve design, it isincumbent upon researchers establishing new fragmen-tation projects to ensure that they address policyquestions that are relevant not only at the time of projectestablishment but also for the foreseeable future.

Focusing on four large-scale forest fragmentationexperiments located on three different continents, wesummarize the key features of existing experimentaldesigns and assess their ability to address emergingissues in landscape ecology. Based on this review, wedevelop and scrutinize the design for the Stability ofAltered Forest Ecosystems (SAFE) Project, a newrainforest fragmentation experiment being establishedin the wet tropical forests of Malaysian Borneo.

2. AN OVERVIEW OF EXPERIMENTAL DESIGNSFOR FOREST FRAGMENTATION STUDIESHabitat area is probably the single most influentialvariable that can be manipulated in a fragmentationexperiment, and has formed the backbone of the designsat the BDFFP, the Calling Lake Fragmentation Exper-iment and the Wog Wog Habitat FragmentationExperiments. All three experiments used replicates of asmall number of fragment size categories, rather thanopting for a more extensive, continuous gradient of unre-plicated fragment sizes. In all cases, fragment sizes were

Phil. Trans. R. Soc. B (2011)

distributed on a log-scale. The BDFFP initially plannedfour size categories on a log10 scale (10

0, 101, 102 and103 ha), but the largest of these was never isolated. Call-ing Lake followed a similar design, but added anintermediate fragment size of 40 ha. Wog Wog, however,had a much smaller forest area available for the exper-iment and used fragment sizes of 0.25, 0.875 and3.062 ha.

Surprisingly, given the island biogeography frameworkon which these experiments were initially designed,isolation (or conversely connectivity) has seldom beenbuilt into large-scale fragmentation experiments. Onlythe Savannah River Site Corridor Experiment hasmanipulated isolation distances, with fragments separ-ated from each other by distances of 64 to 384 m [14].Two other experiments used a coarser approach tomanipulate isolation by introducing a connectedversus isolated treatment [11,15]. A second experimentat the Savannah River site was focused around issues offragment connectivity, with connected versus unconnec-ted patches f