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In the Western Gulf region of the United States cold-tolerant eucalyptus have been explored as pulpwood feedstock. However, non-native plantations may alter understory species diversity, modifying environmental conditions and soil characteristics. Few studies have compared eucalyptus plantations with native ecosystems to understand the impact on understory vegetation in the United States. In this study, we compared understory plant species richness and diversity during 2014–2016 in (1) slash pine (Pinus elliottii) established in 2008, (2) slash pine established in 2013, and (3) and Camden white gum (Eucalyptus benthamii) established in 2013. Overstory characteristics, soil pH, and soil nutrient concentrations were measured to understand factors that affected understory species richness and diversity. Results indicated a decline in understory species richness over time, with Camden white gum in an intermediate condition between same-age slash pine (highest richness) and older slash pine (lowest richness). Leaf area index, soil pH and K, and tree height were the most important factors influencing understory species richness and diversity. The adoption of fast-growing eucalyptus on these sites will probably accelerate the deterioration of natural habitats and reduce open-condition species in favor of shade-tolerant species, overturning the conservation efforts already put in place by governmental agencies and conservation groups. [ABSTRACT FROM AUTHOR]

Highlights • Thinned pine stands have structural conditions consistent with open pine woodlands. • Prescribed fire and herbicide applied after thinning can extend open pine condition. • Duration of open pine condition is influenced by site index and planting density. • Connectivity of open pine patches can facilitate movement for many open pine species. • Gopher tortoises have an even flow of habitat in regenerating and thinned stands. Abstract Pine forests managed for economic return comprise 19% of southeastern U. S. forests and can provide vegetation structure and composition necessary for many wildlife species adapted to open pine conditions. However, in the absence of frequent fire and other disturbance in southeastern pine (Pinus spp.) forests, midstory hardwoods create closed canopy conditions limiting value of pine stands for many endemic, disturbance-adapted wildlife species. Limitations of past research investigating exact mechanisms for producing and maintaining open pine conditions in managed pine systems have led to a paucity of information regarding ecoregion applications and outcomes. This study evaluated (1) to what extent managed pine stands replicate open pine structural conditions and (2) to what extent managed pine stands provide habitat for the gopher tortoise, an open pine keystone species. We used summary statistics from existing literature to identify structural metrics provided by managed loblolly pine (P. taeda) stands and compared them to disturbance-maintained open pine woodlands. We used spatially-explicit forest management simulations to determine amount and configuration of open pine woodland conditions within two large (>9000 ha), economically-feasible managed pine landscapes in the East and West Gulf Coastal Plains ecoregions. As a case study, we estimated availability and connectivity of gopher tortoise (Gopherus polyphemus) habitat, in managed pine stands of the East Gulf Coastal Plains. Pine stands planted at ≤1310 stems/ha (≤530 stems/ac) provide up to four years of "excellent" open pine condition for wildlife following commercial thinning, based on desired conditions for southern pine forests, with temporal availability depending on site quality. Mid-rotation applications of prescribed fire and selective herbicide can extend "excellent" open pine condition initiated by commercial thinning up to an additional four years. Landscape metrics indicated that, under typical management practices, open pine stands can be spatially and temporally connected to the extent necessary to facilitate among-patch movement for many open pine-adapted species of conservation concern. Our landscape analyses indicated tortoises using primarily regenerating and thinned stands potentially can have a relatively even flow of suitable habitat conditions and opportunities to move to adjacent or nearby open stands when currently-occupied stands reach canopy closure. The disturbance regimes inherent in pine plantation management create diverse landscapes that conserve plant and wildlife biodiversity while meeting economic objectives. Therefore, pine plantations may complement current conservation efforts for open pine woodland species dependent on or tolerant of large-scale disturbance and shifting habitat conditions while offering refuge for high vagility species. [ABSTRACT FROM AUTHOR]

Timber harvests may facilitate ant invasions of forested landscapes, fostering interactions between non-native and native ants. Harvests that include removal of low-value woody biomass as forest bioenergy feedstock may reduce residual coarse woody debris, thereby altering food and cover resources for ant species. We manipulated: (1) volume and distribution of coarse woody debris in stand-scale treatments ranging from intensive coarse woody debris removal to no coarse woody debris removal; and (2) coarse woody debris availability at microsite locations within stand-scale treatments, including piles of hardwood stems, piles of conifer stems, and no pile locations in North Carolina, USA and windrows (i.e., long, linear piles of harvest residues) and no windrows in Georgia, USA, in recently clearcut pine plantations ( n  = 4 per state). We captured ants in regenerating stands and tested treatment- and location-level effects on non-native and native ant relative abundances. Invasive ants represented 19% of ant taxa richness, but comprised 94% of total ant captures. Red imported fire ant ( Solenopsis invicta Buren, hereafter “RIFA”) dominated the ant community in young plantations. RIFA avoided windrows, but its relative abundance did not differ among stand-scale treatments. Coarse woody debris retention in stand-scale treatments and at microsite locations favored non-RIFA ants, including Asian needle ant ( Brachyponera chinensis Emery) and several native ant species. Dual invasions of RIFA and Asian needle ant in young plantations of the eastern United States may commonly occur because the two species may not compete for resources on the forest floor. Reduction of coarse woody debris via intensified woody biomass harvesting may negatively affect non-RIFA ant species and promote RIFA colonization, thereby indirectly increasing deleterious effects of RIFA on other wildlife. [ABSTRACT FROM AUTHOR]

Intensively managed pine ( Pinus spp.) forests (IMPFs) in the southern U.S. are often harvested by clearcutting in conjunction with green tree retention (i.e., retention of unharvested or less-intensively harvested trees and other vegetation), which is thought to promote structural diversity and to benefit wildlife. Management units in IMPFs thus primarily consist of regenerating pine clearcuts (RCCs) plus retained cover in streamside management zones (SMZs: vegetative buffers along perennial and intermittent streams) and/or stringers (forested buffers along ephemeral drains). To understand relationships between retained structures and avian communities, we documented and compared species diversity of breeding bird species and avian guilds in three-year-old RCCs and associated SMZs and stringers on 60 IMPF management units within the South Central Plains ecoregion of the southeastern U.S. We detected 5617 individuals of 60 species. Eight species were considered “common birds in steep decline,” one of which was frequently detected (Prairie Warbler, Setophaga discolor ). Three of our 15 most frequently detected species were identified by Partners in Flight as “warranting management attention” for “moderate or high regional declines,” and 19 other species were listed as “warranting management attention” but were uncommonly detected. Forty-two of 44 species documented in RCCs were also observed accessing retention cover areas. SMZs and stringers comprised an average of 17.4% of management unit area, but 27% of species were detected solely in retention cover types. There was an 84% species overlap between SMZs and stringers. Stringers augmented SMZ contributions to site avian diversity by hosting forest specialist guilds. Diversity of early-successional specialists was similar between stringers and RCCs, suggesting stringers also enhanced RCC contributions to site bird diversity. Furthermore, we detected several species only within stringers. Green tree retention land cover contributed to stand scale avian diversity disproportionately to its area, and in particular, stringer cover appeared to enhance the value to avifaunal species diversity of RCC and SMZ patches. [ABSTRACT FROM AUTHOR]

In the southern U.S. (hereafter, South), institutional forest owners engaged in forest certification programs often retain unharvested or less-intensively harvested vegetation when clearcut harvesting intensively managed pine ( Pinus spp.) forests (IMPFs). As a result, IMPF landscapes consist of regenerating forests and associated retained streamside management zones (SMZs), stringers (buffer strips along ephemeral streams), and other forest types and structural classes. Although studies in the South have documented plant and animal communities associated with SMZs, there is a lack of information about stringers. To improve understanding of the potential for stringers to contribute to biodiversity-related management objectives, we characterized stem density and vegetation cover in SMZs and stringers associated with 60 IMPF management units (MUs) in the South Central Plains ecoregion of Arkansas and Louisiana, USA. Snag and log density, midstory pine density, understory deciduous cover, and ground cover were not statistically different in stringers and SMZs; however, overstory (pine and deciduous) and midstory (deciduous) tree density was significantly lower in stringers than in SMZs, and understory pine density was significantly greater in stringers. [ABSTRACT FROM AUTHOR]

Abstract: Although intensively managed pine forests are common in the southeastern US, few studies describe how combinations of mechanical (MSP) and chemical site preparation (CSP) and herbaceous weed control (HWC) techniques affect bird communities that use early successional habitats within young pine forests. Therefore, we examined effects of six treatments of increasing management intensity via combinations of MSP (strip-shear and wide spacing or roller chop and narrow spacing) and CSP (application or no application) treatments with banded or broadcast HWC on bird communities in six loblolly pine (Pinus taeda) plantations in the Coastal Plain of North Carolina, USA, for 8years following site preparation. Wide pine spacing and strip-shear MSP increased bird abundance and species richness over narrow spacing and chopped MSP for 6years after planting. Chemical SP reduced bird abundance in year 2, increased bird abundance in year 6, had no effect on abundance after year 7, and did not affect species richness in any year. Total bird abundance and species richness were similar between banded and broadcast HWC. Site preparation and HWC had no effect on bird diversity and bird communities were most similar in treatments of similar intensity. Site preparation and HWC had few or no effects on birds based upon migratory status, habitat association, or conservation value. The addition of chemical site preparation or HWC had little effect on birds beyond pine spacing, and bird abundance was not proportional to management intensity. Although we observed treatment effects, all treatments provided habitat used by a variety of bird species, and pine plantations may play an increasingly important role in bird conservation as forests become fragmented and converted to other land uses and as natural processes that create early successional habitat, such as fire, are suppressed. [Copyright &y& Elsevier]

The southern United Stales has significant area in managed pine (Pinus spp.) stands that contribute to terrestrial biodiversity via maintenance of forested areas, varied silvicultural practices resulting in diverse plant communities, stands in multiple successional stages interspersed with mature natural forests, and reduction of pressure on natural forests for wood products. However, conservation value of managed forests is dependent on factors such as product target, landscape context, management intensity, rotation length, stocking density, and ownership philosophy. Potential limitations include loss of natural forests, reduction in dead wood, constraints on stand structure, age and size of plantation trees, and economic pressure to increase management intensity. We recommend that landowners develop plans, including metrics for gauging progress, to cost-effectively manage for biological diversity within working forests and communicate outcomes to stakeholders. Forest certification systems offer a formalized approach for meeting biodiversity goals and demonstrating accomplishments. [ABSTRACT FROM AUTHOR]

Abstract: Streamside management zones (SMZs), composed primarily of hardwoods in the southeastern United States, provide habitat diversity within intensively managed pine (Pinus spp.) plantations. However, effects of SMZ width and adjacent plantation structure on riparian wildlife communities are poorly understood. Therefore, during 1990–1995, we examined small mammal communities within 5 SMZ width classes (1–20 to >100m) embedded within three types of pine plantations (young, open canopy; closed canopy; and thinned) and three natural riparian stands in the Ouachita Mountains of Arkansas, USA. We captured small mammals for 10 consecutive days each February using four to six traplines each consisting of nine trap stations with three snap traps at each station. We estimated relative abundance [catch-per-unit-effort (CPUE)], species richness, species diversity, and species evenness for all captures and captures just along the stream course. Within the SMZ/plantation settings and three natural stands, we captured 1701 small mammals of 11 species in 114,285 trapnights. Golden mice (Ochrotomys nuttalli), southern short-tailed shrews (Blarina carolinensis), and Peromyscus spp. comprised 88% of all captures. Our study suggests that narrow (≤20m wide) SMZs in managed pine forests tend to have higher small mammal abundance and species richness than wider SMZs. Additionally, species richness and CPUE was greater in SMZs within young, open canopy and thinned plantations versus closed canopy plantations. Plantation structure appears to influence small mammal community structure within SMZs more than SMZ width. Shortening the amount of time plantations spend in closed canopy conditions would likely improve habitat conditions for small mammals existing in SMZs within intensively managed pine landscapes. Streamside management zones in the South designed to meet voluntary water quality standards are likely sufficient for small mammal conservation. [Copyright &y& Elsevier]

Presents a study that assessed the structure of uneven-aged stands of loblolly and shortleaf pine which were subjected to prescribed winter burn cycles of 0, 3, 6, and 9 years. Methodology; Plot layout and prescribed burning; Species importance; Management implications.