Long-term exclusion of deer may decrease some plant species through interspecific competition. I studied the effects of deer exclosures for 16 y on tall forbs and tree saplings inside and outside three exclosures of beech forest in the Tanzawa Mountains, eastern Japan. Understory cover ranged from 69% to 95%, and herb-layer height ranged from 1.1 to 1.4 m, inside and outside the exclosures. The density of 2–4 of 18 targeted tall forb species was significantly greater inside than outside the exclosures (Mann–Whitney U-test, P < 0.05). No species showed a higher density outside the exclosures. Mature ramet density of tall forbs was greater inside than outside exclosures, with the exception of two species. No clear relationship between forb densities and those of tree saplings was observed. The maximum height of saplings of most tree species exceeded the height of the herb layer. The mode of tree sapling height was 1–2 m and the tree density ≥2 m in height was 2260–5400 ha^–1, whereas no tree saplings >1 m in height were observed outside the exclosures. The results suggested that deer exclusion for 16 y maintained growth of tall forbs and concurrently promoted establishment of tree saplings, and almost no suppression of forbs and tree saplings was induced by the dense understory.

Biological diversity and ecological integrity in native prairies of the northern Great Plains are substantially modified from pre-Euro-American settlement. About 90,000 ha of native mixed-grass and tallgrass prairie are managed by the US Fish and Wildlife Service (Service) in North Dakota, South Dakota, and northeastern Montana. We used belt transects to classify floristic composition of all Service-owned prairies in the Dakotas and northeastern Montana. Prairies were significantly degraded, mainly by invasion of introduced grass and forb species and by native shrubs. In general, floristic integrity of Service-managed prairies was most compromised by smooth brome (Bromus inermis) and Kentucky bluegrass (Poa pratensis). The degradation was, in part, an unintended outcome of long-term management by the Service. The degree of degradation varied spatially across the broad geographic area defined by our study and was invader-specific, corresponding to geographic patterns in precipitation and temperature. Within the study area, floristic quality was relatively high on prairies toward the north and west, where plant growth sites generally were cooler and drier, based on long-term averages. In contrast, growth sites to the south and east generally were warmer, moister, and characterized by lower floristic quality, primarily because they were substantially invaded by smooth brome. Kentucky bluegrass was the most widespread invader of Service-owned prairies, with less frequent occurrence only in prairies dominated by smooth brome, especially in South Dakota or by native grass–forbs, especially in northwestern North Dakota and northeastern Montana. Improved knowledge of geographic and climate-related patterns of plant invasion enhances decision making for protecting northern mixed-grass and tallgrass prairies by focusing restoration efforts where probability of success is greater.

Temperate woodlands are one of the world's ecosystems in greatest need of ecological restoration, but relatively little is known about their floristic recovery dynamics over decadal timescales. From 2000 to 2012, we monitored understory plant communities in a woodland mosaic in Missouri, USA, as it underwent restoration via prescribed, dormant-season burning and mechanical thinning of red cedar (Juniperus virginiana) and exotic shrubs. Native species richness increased linearly by 36% over this time period, driven primarily by an influx of forb species in thin-soiled upland areas where red cedar was removed. Floristic quality also increased with differential dynamics across local communities; forest floristic quality saturated quickly whereas floristic quality increased gradually over the time series in woodlands and red cedar–dominated woodlands. Species that underlay these patterns were mainly ruderal or matrix forbs and grasses with little dependence on intact, undisturbed habitats. In contrast, conservative species were rare or absent. This case study suggests that understory plant recovery dynamics may be slower in harsher and more degraded sites and faster in more mesic sites within a woodland mosaic. Our observations set a benchmark for woodland understory plant recovery dynamics and indicate that a future restoration challenge is to prioritize the managed translocation of dispersal-limited, conservative species.

The restoration of tallgrass prairies is often centered on reestablishing plants, with only minor efforts directed to the fauna that inhabit these areas. Small mammals play important ecological roles in many ecosystems, so understanding how management techniques such as the reintroduction of bison (Bison bison) and prescribed fire affect them can assist in a more comprehensive evaluation of restoration efforts in sites being actively restored. Our objective was to assess impacts of reintroduced bison and prescribed fire in restored prairies on small mammals in the first two years of bison presence. Small mammal abundance decreased with restoration age and time since fire. Small mammal diversity increased with restoration age and was slightly lower in sites where bison were present. Differences in diversity were driven primarily by prairie voles (Microtus ochrogaster), and abundance was driven by deer mice (Peromyscus maniculatus). The mechanism for these impacts is likely habitat availability: fires remove litter and residual dead vegetation, which are important habitat for voles. The removal of litter and residual dead vegetation with fire usually results in a higher amount of bare ground being exposed relative to pre-fire conditions. Although bison impacts may continue to change over time as grazing effects accrue, we demonstrate relatively weak effects of this megaherbivore on small mammal communities. Our results underscore that utilizing bison reintroductions and prescribed fire in concert and employing them to maximize habitat heterogeneity is likely to best maintain small mammal diversity across restored prairies.

Marginal land now devoted to growing harvested crops may be better suited to other land uses such as biodiversity enhancement and carbon sequestration. However, farmers are not encouraged to explore the development of these opportunities due largely to subsidized federal crop insurance (FCI). This study examined FCI outcomes from 2013 to 2017 in 69 Coastal Plain counties of North Carolina and South Carolina. The loss ratio (total crop indemnities paid/total insurance premiums paid) was used to identify 21 counties with high-risk agriculture. Then an index of conservation opportunity was calculated for each county using the loss ratio, insurance subsidy, and an estimate of natural capital (i.e., renewable or nonrenewable natural resources that can provide benefits to humans). Where marginal farmland is surrounded by forest and natural capital is high, the index will identify counties currently supported by FCI that more quickly and completely incorporate the full range of ecological dynamics and biological diversity when farming is abandoned. The top 10 counties for conservation opportunity, with the exceptions of Scotland County, North Carolina, and Marion County, South Carolina, were located in the outer Coastal Plain or coastal zone where natural capital is high. Transitioning land use from harvested crops to biodiversity enhancement or carbon sequestration will require bold changes in agricultural policies and subsidies so that income streams to farmers are maintained while novel ecological targets are met.

In 1996 the Missouri Department of Conservation purchased Pawnee Prairie, a 190-ha mix of remnant tallgrass prairie and formerly row-cropped prairie with varying degrees of Festuca arundinacea invasion and past cattle grazing intensities on rolling terrain in the central dissected till plains ecological section. Management actions implemented over the following 20 y included prescribed fire, herbicide treatments of invasive nonnative species, and seeding of local ecotype prairie seed. Concurrently, four vegetation monitoring transects were sampled for plant species composition and cover five times between 1996 and 2017. Each of the transects increased significantly over time in the following per-quadrat means: % native plant species cover, plant species conservatism, and cover-weighted plant species conservatism. At the site level, native grasses increased by 22%, nonnative grasses declined by 76%, native forbs increased by 91%, nonnative forbs declined by 94%, and native sedges declined by 37%. In 1996 the top species in importance value across all transects included weedy native species (e.g., Dicanthelium lanuginosum) and nonnative species (e.g., Daucus carota). By 2017 the top species had transitioned to characteristic prairie species (e.g., Schizachyrium scoparium). Ordination results documented compositional trends across all transects toward greater native species richness, cover, and species conservatism values. At Pawnee Prairie, 20 y of sustained prairie reconstruction and restoration practices applied across an area of differing land use histories resulted in significant gains in the natural quality of the site's vegetation, including a greater abundance of prairie flora matrix species and some conservative species.

In the Great Lakes Region, minor differences in soils and location (e.g., proximity to the Great Lakes) can lead to strong differences in vegetation; thus, the utility of broad-scale mapping often depends on capturing subtle landscape features and local processes. Similarly, vegetation patterns are in part a result of disturbances that have changed drastically over time, therefore mapping efforts must take into account vegetation–fire relationships to various biophysical settings (e.g., landtype associations, climate, and soils). Despite this, too little attention has been given to potential sources of mapping error, which include data limitations, ecological similarity, community classifications, locational error, sample quality, and lack of knowledge of systems—specifically natural disturbance regimes. We used ∼23,500 plots with detailed vegetation, soils, and classification information to (1) evaluate LANDFIRE (Landscape Fire and Resource Management Planning Tools) historical vegetation (Biophysical Settings or BpS) classifications, (2) refine these classifications based on detailed soil regime and plant associations, and (3) draft fuzzy set soil-classification gradient maps to evaluate uncertainty in mapping and sources of mapping errors. Locally derived reference plot data often did not agree with LANDFIRE BpS mapping even for classifications generalized broadly by Fire Regime Groups. Our fuzzy methodological approach improves decision-making processes by assessing mapping confidence and highlighting potential sources for errors including classifications themselves. Our mapping efforts suggest that soil drainage and productivity data helped to delineate BpS classifications, which may in turn help stratify Existing Vegetation Types into feasible options.

Changes in historical disturbance regimes have increased the susceptibility of Great Plains ecosystems to various threats, including invasive species. Kentucky bluegrass (Poa pratensis; hereafter bluegrass) invasion in the northern Great Plains is displacing native species and has created novel ecosystems with no historical precedent to guide management. Traditional season-long (SL) grazing management increases bluegrass abundance, so we conducted a field experiment to determine if alternative early-intensive (EI) and patch-burn (PB) grazing management strategies can elicit more desirable outcomes in bluegrass-invaded pastures. Alternative EI grazing involved a triple of the stock density, compared to SL and PB stock density, for the first third of the grazing season while PB grazing incorporated SL grazing with prescribed burns. We randomly assigned treatments to 16-ha pastures with three replicates per treatment (n = 3). We conducted vegetation cover surveys and collected aboveground biomass samples to analyze plant community dynamics and production at study initiation and after 4 y of treatment. The SL grazing treatment increased bluegrass abundance by approximately 20% after 4 y of treatment while the alternative EI and PB grazing maintained its abundance at study initiation levels. Compositional differences also indicated increased native plant species cover with alternative management. Annual aboveground biomass production was not affected by management, but has the potential to become less variable with PB grazing in bluegrass-dominated pastures. Our results provide promising evidence that alternative grazing management may help combat bluegrass invasion by preventing additional increases in its abundance in the northern Great Plains.

North America harbors a rich native flora of crop wild relatives—the progenitors and closely related species of domesticated plants—as well as a range of culturally significant wild utilized plants. Despite their current and potential future value, they are rarely prioritized for conservation efforts; thus many species are threatened in their natural habitats, and most are underrepresented in plant genebanks and botanical gardens. Further coordination of efforts among land management, botanical, and agricultural science organizations will improve conservation and general public awareness with regard to these species. We present examples of productive collaborations focused on wild cranberries (Vaccinium macrocarpon and Vaccinium oxycoccos) and chile peppers (Capsicum annuum var. glabriusculum). We then discuss five shared priorities for further action: (1) understand and document North America's crop wild relatives and wild utilized plants, (2) protect threatened species in their natural habitats, (3) collect and conserve ex situ the diversity of prioritized species, (4) make this diversity accessible and attractive for plant breeding, research, and education, and (5) raise public awareness of their value and the threats to their persistence.

White-tailed deer (Odocoileus virginianus) are now the dominant large herbivores in tallgrass prairie ecosystems of the U.S. Midwest and have unique ecological impacts compared to the historically dominant bison (Bison bison) and elk (Cervus elaphus) that were extirpated from this region. While most of our knowledge of white-tailed deer impacts on plant communities and ecosystem processes comes from forested habitats, relatively little research has focused on deer effects in prairies. In this review, we discuss the ecological impacts of white-tailed deer in North American tallgrass prairies, potential deer management strategies, and areas of future research.

Unlike bison and elk, deer are selective grazers that preferentially eat nutrient-rich forbs. At high deer densities, this consumption of forbs can have negative effects on prairie biodiversity and alter nutrient cycling. Deer can decrease plant diversity by reducing the abundance and reproductive success of their preferred plant species, shifting the plant community to one dominated by species avoided by deer or tolerant of herbivory.

At lower densities, deer may maintain biodiversity in accordance with the intermediate disturbance hypothesis. Deer are able to maintain a balance between deer-avoided and deer-preferred species abundance by giving unpreferred or herbivory-tolerant species an advantage, but not completely suppressing herbivory-sensitive species. Nonconsumptive deer impacts also influence prairies through transporting invasive species, trampling on deer trails, and redistributing nutrients in fecal pellets and carcasses. Management strategies such as hunting, use of fences, and patch-burning can alleviate the pressures of overabundant deer populations, while maintaining their ability to promote heterogeneity.