Effects of Landscape Structure in Florida Scrub: A Population Perspective

Hokit, D. Grant; Stith, Bradley M.; Branch, Lyn C.

doi:10.2307/2641173

Cited by 38 publications

(73 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Overall, in 14 of 19 (73.7%) studies in which habitat quality of focal patches was considered, habitat quality of source patches was ignored when measuring connectivity (Appendix). We are responsible for such an inconsistent treatment of patch quality in some of our own research (Hokit et al 1999;Schooley and Wiens 2005; but see Hokit et al 2001;Branch 2007, 2009).…”

Section: Mini-review Resultsmentioning

confidence: 95%

“…Researchers now recognize that quality of focal patches can affect local extinctions, colonizations, and occupancy (Thomas 1994;Hokit et al 1999;Fleishman et al 2002;Franken and Hik 2004;Armstrong 2005;Thornton et al 2011). Patch areas can be weighted by habitat quality to create a more ecologically relevant measure termed 'effective patch areas' (Hanski 1994;Hokit et al 2001).…”

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

Habitat quality of source patches and connectivity in fragmented landscapes

Schooley

Branch

2011

Biodivers Conserv

Self Cite

View full text Add to dashboard Cite

Because spatial connectivity is critical to dispersal success and persistence of species in highly fragmented landscapes, the way that we envision and measure connectivity is consequential for biodiversity conservation. Connectivity metrics used for predictive modeling of spatial turnover and patch occupancy for metapopulations, such as with Incidence Function Models (IFM), incorporate distances to and sizes of possible source populations. Here, our focus is on whether habitat quality of source patches also is considered in these connectivity metrics. We propose that effective areas (weighted by habitat quality) of source patches should be better surrogates for population size and dispersal potential compared to unadjusted patch areas. Our review of a representative sample of the literature revealed that only 12.5% of studies incorporated habitat quality of source patches into IFM-type connectivity metrics. Quality of source patches generally was not taken into account in studies even if habitat quality of focal patches was included in analyses. We provide an empirical example for a metapopulation of a rare wetland species, the round-tailed muskrat (Neofiber alleni), demonstrating that a connectivity metric based on effective areas of source patches better predicts patch colonization and occupancy than a metric that used simple patch areas. The ongoing integration of landscape ecology and metapopulation dynamics could be hastened by incorporating habitat quality of source patches into spatial connectivity metrics applied to species conservation in fragmented landscapes.

show abstract

Section: Mini-review Resultsmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 98%

Habitat quality of source patches and connectivity in fragmented landscapes

Schooley

Branch

2011

Biodivers Conserv

Self Cite

View full text Add to dashboard Cite

show abstract

“…Scrub patches on APAFR and ASF are isolated naturally by mesic and hydric habitat. Prior to sampling, we delineated clusters of patches within each ridge so that gaps between neighboring patches were no greater than 750 m, the estimated maximum dispersal distance for scrub lizards (Hokit et al 1999). This resulted in one cluster of patches on ASF and two clusters, referred to as north and south, on APAFR ( Fig.…”

Section: Methodsmentioning

confidence: 99%

“…These studies showed deep genetic separations among disjunct ridges and population structure within ridges. Experimental field studies also suggest that movement of lizards is limited by mesic and hydric habitat that separates scrub patches (Tiebout and Anderson 1997;Clark et al 1999;Hokit et al 1999). State and federal conservation initiatives for scrub habitat focus on establishment of an archipelago of reserves (United States Fish Wildlife Service 1991; The Nature Conservancy 1991).…”

Section: Introductionmentioning

confidence: 97%

Ecological metrics predict connectivity better than geographic distance

et al. 2009

Self Cite

View full text Add to dashboard Cite

We use microsatellite loci to examine genetic structure of the Florida scrub lizard (Sceloporus woodi) and test for the effects of landscape variables at the scale of neighboring patches. We evaluate ecological metrics of connectivity with genetics data, which to our knowledge is the first application of these particular metrics to landscape-level genetics studies in Florida scrub. Florida scrub is a highly threatened ecosystem in which habitat patches are remnants of a previously widespread xeric landscape. Analysis of mitochondrial DNA (mtDNA) has shown that landscape structure influenced the evolutionary history of the Florida scrub lizard (S. woodi) across its range. Our results concur with these mtDNA studies in documenting divergence between xeric ridge systems and also demonstrate divergence at very local scales. Both least-cost distance and pairwise isolation (a metric used in ecological studies that includes patch size, quality and a modified isolation index) were better predictors of genetic distance than Euclidean distance, indicating that mesic and hydric habitat influence spatial patterns in genetic variation. Our results support the need for focusing on spatial distribution of scrub habitat at the scale of neighboring patches, as well as regionally, in conservation management and restoration. Also, our study points to the value of integrating landscape ecology metrics into landscape genetics.

show abstract

“…Lower mobilities may increase vulnerability to local extinction to a greater extent than for birds, mammals and butterflies (birds: see Simberloff 1995;Wiens 1995;Mac Nally and Bennett 1997; reptiles: see Sarre et al 1995;Webb and Shine 1997;Coddington and Cree 1998;Hokit et al 1999). …”

Section: Introductionmentioning

confidence: 99%

Reptiles and habitat fragmentation in the box-ironbark forests of central Victoria, Australia: predictions, compositional change and faunal nestedness

2001

View full text Add to dashboard Cite

There are few published accounts addressing the impact of habitat fragmentation on biodiversity of terrestrial reptiles. Here we provide information on the saurofaunas of fragments of box-ironbark forest of central Victoria, south-eastern Australia, gathered over three years. Data for fragments of four size classes (10 ha, 20 ha, 40 ha, 80 ha) are compared with similar information for 'reference areas', which are sites of the same range of areas but set within large blocks of continuous forest (>10,000 ha). These comparisons are used to differentiate fragmentation effects from normal species-area relationships. Two sets of data are presented. One is an 'extensive' set based on 68 fragments and reference areas surveyed by using transect counts and area searches. The other 'intensive' set also included pitfall trapping, but was restricted to just 17 fragments and reference areas. The reptilian fauna generally was both depauperate and of low abundance. Differences in capture-rates and species richness between fragments and reference areas collectively are minor, but there are significant differences in species richness between area classes. While fragmentation does not seem to be influential on total numbers and richness, there are important differences in the occurrence of certain species. The two most abundant species in reference areas were very rare in fragments, while a number of species were either in much greater numbers or only occurred in fragments. Many of the observed distributions were consistent with predictions made prior to the study on differences in vulnerability between species. We show that the saurofaunas are 'nested subsets' by area, with strongest nesting apparent in the intensive data-set for reference areas.

show abstract

Effects of Landscape Structure in Florida Scrub: A Population Perspective

Cited by 38 publications

References 39 publications

Habitat quality of source patches and connectivity in fragmented landscapes

Habitat quality of source patches and connectivity in fragmented landscapes

Ecological metrics predict connectivity better than geographic distance

Reptiles and habitat fragmentation in the box-ironbark forests of central Victoria, Australia: predictions, compositional change and faunal nestedness

Contact Info

Product

Resources

About