Changes in vegetation structure and gopher tortoise population structure after 17 years of restoration management

Rebecca C. Pudner; Hardin Waddle; Suzi P. Mersmann; John S. Kush; Craig Guyer; Sharon M. Hermann

doi:10.3375/21-3

Home/Archive/USGS

USGS · 70230264

Changes in vegetation structure and gopher tortoise population structure after 17 years of restoration management

Rebecca C. Pudner·Hardin Waddle·Suzi P. Mersmann·John S. Kush·Craig Guyer·Sharon M. Hermann

View original source ↗Export metadata ↓

Abstract

We examined a study plot sampled in the Conecuh National Forest of southern Alabama in 1999 and again in 2016 after stand thinning and persistent prescribed fire were used to improve habitat quality. These management activities were designed, in part, to enhance habitat quality for the gopher tortoise ( Gopherus polyphemus ), a species considered for protection under the Endangered Species Act because of range-wide population declines. Comparisons of vegetation structure were made at burrows that were active in 1999 and remained active in 2016, and at burrows that were active in 1999 but were classified as abandoned in 2016. Burrows that remained active across this span of time were distinctive in retaining a greater reduction of canopy cover and lacking hardwoods while having a high percentage of longleaf pine in neighboring canopy trees. Active burrows that were abandoned in 2016 were distinctive in possessing hardwoods among neighboring canopy trees, lacking pine seedlings in the midstory, and having increased frequency of legumes and decreased bare ground in the understory. All burrows experienced a decrease in canopy cover and an increase in distance to, and dbh of, neighboring canopy trees; all burrows also had a decrease in litter and non-legume forbs as well as an increase in shrub stems in the understory and midstory. These results indicate that management activities were successful in opening canopy cover but were largely unsuccessful at reducing shrub stems and increasing understory grasses and forbs. Nevertheless, burrows of gopher tortoises increased in abundance during this time period. The size distribution of these burrows changed from a unimodal distribution dominated by adults to a bimodal distribution indicative of increased juvenile recruitment. Thus, the gopher tortoise population increased in association with vegetation changes that suggest tortoises are more sensitive to shading caused by canopy closure than they are to available forage.

Explore related subjects

Natural Areas Journal Article

Source-reported bounding extent: 31.016235250004833° to 31.061095508655708° latitude; -86.7139720916748° to -86.65655136108397° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Rebecca C. Pudner, Hardin Waddle, Suzi P. Mersmann, John S. Kush, Craig Guyer, Sharon M. Hermann. 2021. Changes in vegetation structure and gopher tortoise population structure after 17 years of restoration management. https://doi.org/10.3375/21-3

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2026

Conducting feasibility assessments of potential conservation reintroductions: A case study with the imperiled foothill yellow-legged frog, Rana boylii

Conservation translocations are an increasingly common and often necessary component of recovering species that have become extirpated from portions of their range. Understanding and ameliorating potential threats that reduce the likelihood of successful population establishment at recipient sites is a key component of successful translocation planning. We examined multiple potential threats, including pathogens, contaminants, and invasive species, as well as habitat suitability and food resources, to assess the feasibility of reintroducing threatened, stream-obligate foothill yellow-legged frogs, Rana boylii , to Pinnacles National Park. Foothill yellow-legged frogs were extirpated from this protected area more than half a century ago. Although invasive species, disease, contaminants, food resources, and water temperatures are unlikely to inhibit foothill yellow-legged frog population establishment, potential recipient streams at Pinnacles National Park had shorter hydroperiods and much higher canopy cover than reference streams with extant foothill yellow-legged frog populations. Although the exact cause of extirpation of foothill yellow-legged frogs from Pinnacles National Park is unknown, translocations of foothill yellow-legged frogs to the park are more likely to succeed if riparian canopy cover is reduced and stream hydroperiods increased to better match those at nearby populations. Thoroughly understanding the threats to and characteristics of potential recipient sites could improve the likelihood of success of translocation outcomes in natural areas.

California↗

USGS2026

A template for integrated ecological restoration planning, implementation, and monitoring: Case study from the Little Saint Francis River Chat Pile mining site

We present here a template for integrated ecological restoration planning and monitoring, using a case study from the Little Saint Francis River chat pile restoration site in Madison County, Missouri, USA. We used US Department of Agriculture Ecological Site Descriptions (ESDs) to identify a range of potential target vegetation communities given the site's biophysical setting. Preliminary site inspection allowed qualitative assessment of current vegetation condition in relation to potential ESD community types and identification of broad restoration goals (for example, “restore woodlands”). By examining the results of the site assessment with ESD descriptions, we identified specific and achievable objectives for those goals as well as relevant metrics for monitoring vegetation change through time. Pre-restoration vegetation sampling enabled refinement of objectives and quantified conditions against which to assess change as restorations mature. Because the sampling methods were adopted to address the specific objectives for the restoration, they continue to provide the framework for monitoring vegetation changes following restoration implementation. Herein we describe how this approach was applied in each of the broad community types encountered at the Little Saint Francis River site, relating pre-restoration species abundance measures to abundance values typical of community types associated with each ESD. In so doing, we demonstrate an iterative, data-driven process that can be applied to restoration planning and monitoring in many ecological systems and restoration contexts.

Missouri↗

USGS2026

A little-known piñon from the Mogollon Highlands: Natural history of Pinus x fallax in the Prescott National Forest, Arizona, USA

The Mogollon Highlands is an area of rich biodiversity in central Arizona and western New Mexico. The piñon-juniper/chaparral in the Mogollon Highlands is unique from other piñon-juniper woodlands in both taxonomy and structure. The hybridization of the common piñon there, Pinus × fallax (Mogollon Highlands piñon, MHP), is hypothesized to render it more tolerant to heat and aridity than one of the parent plants, Pinus edulis (Colorado piñon). Yet as Climate Water Deficit continues to increase, so does concern for the future of these woodlands and the MHP. Using demographic data on MHP from the last four decades, we evaluate fecundity and mortality patterns in woodlands where MHP is co-dominant with three Juniperus species and numerous perennial shrubs. Our data indicate that MHP stands continue to reproduce and that mortality is low relative to the more northern P. edulis stands. We also present a simple calculation of historical fire rotation in Prescott National Forest woodlands, estimating a fire rotation of two centuries, far shorter than other piñon-juniper associations. We also explore fire patterns since 1985 across the ecoregion; abundant charcoal indicates small patchy fires were common. In spite of widespread fires, most Mogollon Highlands fires have occurred in Pinus ponderosa (ponderosa pine) forests, leaving piñon-juniper/chaparral intact. Together these trends indicate that MHP and associated perennial co-dominants are tolerant of current climates. We suggest that hybrid genetic combinations, the complex perennial understory (e.g., actinorhizal shrubs, rich diversity of nurse microsites), and fire patterns are responsible for this resiliency.

Arizona↗