Herbaceous Ground Cover Research Articles

도시공원 생태적 배식의 조성 단계별 문제점 고찰 및 개선방안 -서울시 여의도공원 자연생태의 숲을 사례로-

본 연구에서는 국내 현실을 고려한 도시공원의 생태적 배식기법을 마련하기 위해 여의도공원 자연생태의 숲의 조성단계별 문제점과 원인을 고찰하여 개선방안을 제시하였다. 실시설계단계에서는 가장 중요한 배식모델과 도면작성이 불명확하게 제시되었고, 식재수량 및 규격이 비현실적이었다. 시공단계에서는 설계도면과 다른 유사수종 및 다른 규격의 수목이 식재되었고, 목표군락에 따른 토양환경 기반 조성이 이루어지지 못해 생태적 배식에 한계가 있었다. 관리단계에서는 하자보식 처리가 미흡하고, 하자보수 담보기간 이후의 관리대책이 부재하였다. 도시공원 생태숲 조성을 위한 단계별 개선방안을 제시하였다. 실시설계단계에서는 반드시 목표 배식모델을 고려하여 교목층, 아교목층, 관목층별 식재도면을 작성해야 하고, 수목 자원조사결과를 통해 현실적으로 가능한 식재종 및 규격을 제시해야 한다. 시공단계에서는 이식대상 수목에 인식표를 부착하여 적정한 식재종 및 규격으로 식재가 이루어져야 하며, 수종 변경시 식재모델에 적합한지를 검토하도록 시방서에 명기하고, 규격 변경시 실제규격으로 준공처리를 하고, 목표모델에 적합한 토양이 유입될 수 있도록 반입 토양의 의무적인 분석이 필요하다. 관리단계에서는 관급수목에 대한 하자처리를 위해 설계시 일정 할증율을 반영하고, 하자보수 담보기간을 2년에서 5년으로 확대하며, 시간변화에 따른 목표군락별 변화과정을 관찰할 수 있도록 준공후 5년 동안 모니터링 의무화 등이 필요하다. This study was carried out to analyze the problems on several steps of the establishment of the Nature Ecological Forest in Yeouido Park, Seoul, and also to suggest improved approaches on each step. For execution drawing, planting models and plans seemed to be uncertain, and the quantity and size of planting trees seemed to be impractical. For construction, the woody plants planted on the site were different in species and size from the planting plan. Ecological planting was somewhat limited because of the inappropriate soil properties. For management, replacement of the dead trees was not executed properly, and no management scheme was prepared after the replacement period. We suggested improved approaches for the establishment of ecological forests in urban areas as follows: for execution drawing, overstory, understory and herbaceous ground cover layers should be composed based on standard plant community structures. Trees that are available from tree markets should be specified in the planting plan. For construction, trees for planting need to be tagged to identify species and size. When tree species and size are changed, they should be checked to ensure that they are proper to the plant community model. Soil information should be collected to check that they fit the target plant community model. For management, the proper amount of trees needs to be specified in the planting plan by applying regular discount rates, especially for trees supplied from the government sector. The replacement period should be extended from two years to five years. The change of plant communities should be monitored during first five years after establishment.

Effects of forest fragment management on vegetation condition and maintenance of canopy composition in a New Zealand pastoral landscape

AbstractResidual forest fragments in areas dominated by pastoral agriculture can have high value for biodiversity conservation but are still subject to ongoing degradation as (i) processes initiated by fragmentation continue to operate, for example, changes in canopy replacement probabilities; and (ii) deleterious processes impinge upon them from the surrounding matrix, for example, browsing and trampling by vagrant livestock. Responses by management to slow or reverse these processes require evaluation. Stock (mainly cattle and sheep) exclusion by fencing and mammal pest (mainly Trichosurus vulpecula (brushtail possum)) control are currently used as management tools to maintain or improve the vegetation condition of fragments in New Zealand. We examined the effectiveness of these tools by sampling vegetation composition, forest structure and regeneration of woody species in 41 old‐growth fragments dominated by Beilschmiedia tawa, selected to populate a factorial design that included four different fencing classes (unfenced, fenced 2–10, 10–20 and >20 years ago), with and without sustained mammal pest control. Fencing for more than 10 years led to higher abundances of native ground ferns and shrubs, and lower abundances and numbers of mostly adventive herbaceous ground cover species. In contrast, lianes were less abundant with mammal pest control, whereas herbs were more abundant. Fencing led to a high‐density pulse of seedlings and saplings of woody species within 10 years that then thinned. Mammal pest control allowed increases in abundance of some species palatable to T. vulpecula, and increased the ratio of canopy to subcanopy seedlings in the regeneration pulse caused by fencing. Neither treatment, however, led to the restoration of indigenous species richness to reference forest levels, nor allowed densities of juveniles of shade‐tolerant canopy species to establish to levels commensurate with replacement of existing canopy trees. Most woody seedlings that established following fencing were of short‐lived subcanopy species. These management actions will therefore slow but not reverse the long‐term degradation of these forest fragments, which will eventually differ substantially from continuous forest under current management regimes. Additional measures such as replanting may be necessary not only to ensure replacement of some current species but also to restore lost species.

Forest scenic esthetic assessment - a case study of Taiwania cryptomerioides plantations in the Liouguei Experimental Forest.

This study adopted integration of Scenic Beauty Estimation (SBE) and a cognition model as the research method to understand a sustainable approach to scenic esthetics of Taiwania plantations. The study site was located in Taiwania plantation forests in the Fang-Kang area of the Liouguei Experimental Forest. The respondents were investigated to reveal their scenic preferences, biophysical attributes, and perceptions of cognitive factors including formal esthetic attributes using projected photo images. RMRATE software was used to transfer scores of scenic preferences into SBE values. Then, all data were analyzed by a variance analysis and regression technique. The results indicated that no significant difference was shown in SBEs between students and non- students. It was shown that the ”unity” and ”graduation” of formal esthetic attributes of the investigated cognitive factors had positive effects on scenic preferences. In the analysis of the effect of biophysical attributes on scenic preferences, respondents preferred forest near-view scenes with greater percentage of herbaceous ground cover, less downed wood/debris on the ground, and a higher height to crown base of trees. Furthermore, it was observed that a greater percentage of herbaceous ground cover and less downed wood/debris resulted in higher ratings in the formal esthetic attributes of ”unity” and ”graduation” which positively influenced scenic preferences. Apparently, dealing with relationships of formal attributes (”unity” and ”graduation”) and biophysical attributes (percentage of herbaceous ground cover and downed wood/debris) should be seriously considered in designing scenic esthetics of Taiwania plantations.

Habitat succession, hardwood encroachment and raccoons as limiting factors for Lower Keys marsh rabbits

The Lower Keys marsh rabbit (LKMR, Sylvilagus palustris hefneri), a marsh rabbit subspecies endemic to the Lower Keys, Florida was protected in 1990, however, populations continue to decline despite recovery efforts. We hypothesized on-going habitat loss and fragmentation due to succession and hardwood encroachment has lead to increased edge, reduced habitat quality, and increased activity by native raccoons ( Procyon lotor). These factors reduce the suitability of patches in a later successional state, thus threatening LKMR recovery and metapopulation persistence. We surveyed 150 LKMR patches in 2008, tallying adult and juvenile rabbit pellets, estimating measures of habitat succession and quality (woody and herbaceous ground cover, distribution of herbaceous species) and recording raccoon activity (number of raccoon signs). We calculated patch edge (patch shape index) using ArcGIS. We evaluated the relationship between patch and habitat attributes and LKMR using regression analysis and model selection. We found both adult and juvenile LKMR pellet counts were lower in patches with higher shape indices and higher in patches with greater occurrence of bunchgrasses and forbs. We also found adult LKMR pellet counts were lower in patches with higher raccoon activity. Our results suggest patch edge, habitat succession and quality, and raccoons pose a threat to the persistence and recovery of LKMR populations. Recovery efforts should focus on reducing these trends through habitat management and raccoon removal implemented in carefully controlled experiments with proper monitoring. Measures of patch and habitat attributes important to LKMR should be incorporated into long-term metapopulation monitoring and used to evaluate recovery actions.

Susceptibility of Longleaf Pine Forest Associations in South Mississippi to Invasion by Cogongrass [Imperata cylindrica(L.) Beauv.

If fire affects spread of cogongrass (Imperata cylindrica), a non-native grass that displaces native plants, managers can determine best use of resources to restore and maintain the diverse herbaceous groundcovers of longleaf pine-bluestem (Pinus palustris - Andropogon spp. and Schizachyrium spp.) forests of the southeastern United States. In 2003 and 2004, we measured rates of vegetative encroachment of cogongrass into burned and unburned pine-bluestem and pine-shrub forests one and two years post-burning on Camp Shelby Training Site, Mississippi. Linear growth and tiller production were significantly greater in pine-bluestem forests compared to pine-shrub forests for both time periods. Cogongrass growth was not affected by burning in either forest type one-year post-burning, but was significantly greater in burned forests after two years of growth. Two-years post-burning, mean linear growth of cogongrass was 235 cm in burned pine-bluestem, 139 cm in unburned pine-bluestem, 177 cm in burned pine-shrub, and 92 cm in unburned pine- shrub. Tiller production/m2 for 2004 was greatest in pine-bluestem burned plots and least in pine-shrub unburned plots. Linear growth of cogongrass was significantly and positively correlated to percent cover of adjacent herbaceous vegetation but tiller numbers were significantly and negatively correlated to percent cover of adjacent shrubs. Efforts to restore pine-shrub forests to pine-bluestem forest conditions should implement control of cogongrass before and after use of Are. Vigilant control efforts are needed as restoration shifts conditions to those of pine-bluestem forests and increases susceptibility to cogongrass invasion.

Effects of resource availability on seedling recruitment in a fire-maintained savanna

The herbaceous ground cover of the longleaf pine ecosystem harbors the highest plant species richness in North America, with up to 50 species per square meter, but the mechanisms that regulate this diversity are not well understood. In this system, variability in seedling recruitment events may best explain the extremely high small-scale species richness and its relationship to soil moisture and system net primary productivity. To understand the potential mechanistic controls on species richness, we used a long-term resource manipulation study across a natural soil moisture gradient to assess environmental controls on seedling recruitment. We considered the availability of resources to be an indicator of seedling safe-site supply, and also manipulated seed availability to examine the relative importance of recruitment limitations on seedling diversity. We found that water availability regulated the number of species in the seedling community regardless of the underlying natural moisture gradient, and that this effect may result from differential responses of seedling guilds to resource availability. Water supply was more important than seed supply in determining seedling establishment, suggesting that appropriate sites for regeneration are a factor limiting seedling success. This is the first study that shows that the episodic supply of microsites for recruitment could influence species richness in the highly threatened and biodiverse longleaf pine savanna.

COMPOSITION AND STRUCTURE OF AN IN SITU MIDDLE PENNSYLVANIAN PEAT-FORMING PLANT ASSEMBLAGE BURIED IN VOLCANIC ASH, RADNICE BASIN (CZECH REPUBLIC)

A three-dimensional reconstruction is provided of the composition, spatial distribution, and structure of a single-aged, Middle Pennsylvanian (Moscovian) peat-forming forest of a high-ash, planar (rheotrophic) mire, buried in situ by volcanic ash and preserved in the Lower Radnice Coal of the Radnice Basin (Czech Republic). The reconstruction is based on a detailed taxonomic and taphonomic analysis of fossils in a ∼0.5-m-thick tuff bed at the base of the Whetstone Horizon excavated over an area of 93.5 m 2 . In all, 24 whole-plant taxa of various growth forms were identified. This assemblage represents a lepidodendrid- and Cordaites borassifolius -dominated forest, with a well-developed understory of subarborescent lycopsids, tree ferns, medullosan pteridosperms, and calamites, as well as herbaceous ground cover. Lycopsids were dominated by Lepidodendron simile bearing Flemingites -type cones and L. lycopodioides ; Lepidophloios cf. acerosus was subdominant. Lianas, mostly lyginopterid pteridosperms and some ferns, were usually found close to upright stems. The ground cover, mostly ferns and sphenophyllaleans, was taxonomically the most diverse stratum, although only a minor contributor to the peat. Based on samples from the coal roof, the palynological record is in agreement with the tuff bed assemblage except for the quantity of certain taxa. To reduce this bias, compression R-values were calculated from the percent cover of aerial plant parts in the excavation and in the dispersed palynoflora. These R-values suggest that in the palynological record, arborescent lycopsids and sphenophylls are greatly overrepresented, ferns and cordaites strongly underrepresented, and calamites are almost the same in both records.

English

Reforestation of the Appalachian coalfields with native hardwoods is becoming increasing popular. However, establishing some hardwood species has been difficult due to the poor quality of many mine soils. The purpose of this study was to contrast after 15 years the growth, survival, and overall performance of seven hardwood species planted on three mine sites in Southwestern Virginia. The seven hardwood species were divided into species groups of a non-native fuelwood species, upland hardwoods, riparian species, and a valuable but off-site hardwood species. Overall tree performance was examined as a function of mine soil chemistry and fertility. Eastern cottonwood grew fastest, and black walnut grew slowest. By age 15, the native hardwoods, white and northern red oaks and yellow poplar, grew better than the American sycamore and white ash riparian species. They also responded to a mine soil fertility gradient while the others did not. The overall forest capability of the post-mined condition of these sites was far less than the pre-mined capability. The average weighted site indices (by extent of all soil series) of 10,000 acres in the vicinity of the mined sites are 82 and 77 for yellow poplar and northern red oak, respectively. Reduction in yellow poplar site index between the preand post-mined capability was 26 feet, and the difference for red oak was 15 feet. Northern red oak, white oak, and yellow poplar, all upland native commercial hardwood species, would be better choices for general reforestation than riparian species; however, better reclamation procedures then those used when this study was established (compacted mix of overburden materials with heavy herbaceous ground cover) are needed to restore forest land capability to pre-mining conditions. Additional

Are vegetation—environment relationships different between herbaceous and woody groundcover plants in barrens with shallow soils?

The extent to which woody vegetation exhibits more expansive community structures and different relationships with environmental variables than herbaceous plants is poorly understood in savannas and barrens worldwide, especially those with shallow soils. We explored this question in oak barrens, which are savanna habitats characterized by shallow soils, in southern Ohio, USA. Groundcover plant aerial cover and environmental data were collected using 75 randomly located 1-m2 quadrats in 3 barrens. A combination of non-metric multidimensional scaling (NMDS) and β-flexible cluster analysis revealed 3 distinct herbaceous plant assemblages that varied in abundances of C4 and C3 graminoid species and several forbs. Herbaceous vegetation patterns were correlated with soil acidity, soil depth, plant available water, and especially soil organic matter and quadrat slope. By contrast, woody plants were more widely distributed than herbs, and woody vegetation patterns were strongly correlated only with soil organic matter, although they were weakly associated with quadrat slope and an index of tree influence. The expansion of woody plants into barrens is likely not restricted by most edaphic factors; thus, barrens are highly susceptible to woody plant encroachment that has been fostered by anthropogenic alterations to natural fire regimes (suppression, dormant season fires). We hypothesize that fires that are intended to mimic natural lightning fires during the growing season will be most effective in deterring woody plant encroachment.

Variation in exotic and native seed arrival and recruitment of bird dispersed species in subtropical forest restoration and regrowth

Invasive bird-dispersed plants often share the same suite of dispersers as co-occurring native species, resulting in a complex management issue. Integrated management strategies could incorporate manipulation of dispersal or establishment processes. To improve our understanding of these processes, we quantified seed rain, recruit and seed bank density, and species richness for bird-dispersed invasive and native species in three early successional subtropical habitats in eastern Australia: tree regrowth, shrub regrowth and native restoration plantings. We investigated the effects of environmental factors (leaf area index (LAI), distance to edge, herbaceous ground cover and distance to nearest neighbour) on seed rain, seed bank and recruit abundance. Propagule availability was not always a good predictor of recruitment. For instance, although native tree seed rain density was similar, and species richness was higher, in native plantings, compared with tree regrowth, recruit density and species richness were lower. Native plantings also received lower densities of invasive tree seed rain than did tree regrowth habitats, but supported a similar density of invasive tree recruits. Invasive shrub seed rain was recorded in highest densities in shrub regrowth sites, but recruit density was similar between habitats. We discuss the role of microsite characteristics in influencing post-dispersal processes and recruit composition, and suggest ways of manipulating these processes as part of an integrated management strategy for bird-dispersed weeds in natural areas.

Longleaf Pine (Pinus palustrisP. Mill.) Restoration Using Herbicides: Overstory and Understory Vegetation Responses on a Coastal Plain Flatwoods Site in Florida, U.S.A.

A study was conducted on a Coastal Plain flatwoods site in Florida to determine the effects of common forestry herbicides on Longleaf pine seedling survival and growth and on the understory vegetation. Following removal of the overstory slash pine, five low-rate herbicide treatments were applied over the top of planted Longleaf pine seedlings to provide short-term understory vegetation control and accelerate seedling growth. The objective was to increase Longleaf pine growth by reducing the shrub competition while increasing the herbaceous ground cover. Despite causing reduction in seedling survival over the control treatment, imazapyr (0.21 ae kg/ha) resulted in the highest seedling growth (height and volume). The significant reduction of shrub cover, density, and height by imazapyr was believed to be responsible for the improved seedling growth in this treatment. Both hexazinone (0.56 ai kg/ha) and sulfometuron methyl (0.26 ai kg/ha) + hexazinone (0.56 ai kg/ha) treatments also reduced cover of Runner oak, a major shrub species, but the response was evident only 8 months after treatment. Although sulfometuron methyl (0.26 ai kg/ha) and sulfometuron methyl + hexazinone treatments did not result in any significant change in overall grass, forb, and shrub cover, both treatments resulted in greater Longleaf pine growth compared to the control. None of the herbicides significantly affected the major understory grasses and forbs. Overall, imazapyr provided the best desired results with significant increase in seedling growth and better control of shrub species with no significant effects on grass and other herbaceous species cover.

English

During the past five years, a forestry reclamation approach has been adopted by some coal companies. To ensure adequate tree survival and growth, competition from erosion control groundcovers must be reduced. The purpose of this study was to test the effect of herbaceous groundcover on reforestation success after five years for Phase III bond release. An herbaceous ground cover mix consisting of orchard grass, redtop, birdsfoot trefoil, and red clover was hydroseeded on reclaimed mined land in Wise County, Virginia. The mine soil was a mix of weathered sandstone and unweathered siltstone that was lightly graded and left uncompacted. The following winter, 100 each of white oak, red oak, sugar maple, white ash, and tulip poplar (crop trees) were mixed and planted per acre. An additional wildlife mix of crab apple, dogwood, white pine, and bristly locust was planted at a combined rate of 100 trees/ac. Three half-acre treatment plots were spot-sprayed with Roundup herbicide (3-ft circle around each tree, achieving 70% groundcover (reduced cover) for three years, and three half-acre treatments were left untreated (full cover). After five years, average crop-tree survival rates were 58% and 69% on the untreated plots (full cover) and sprayed (reduced cover) plots, respectively. The actual numbers of trees planted by the professional tree planting crew were 687 and 663 per acre for the full cover and reduced cover plots, respectively. After five years, 415 and 419 surviving trees per acre remained which exceeded the minimum number needed for bond release in Virginia. Tree growth on the full cover plots was suppressed, but growth was excellent on reduced cover plots compared to that expected for these species on undisturbed sites. Reduced cover doubled the growth rate for most species except for red oak, which grew three times faster, and white ash, which grew four times faster when released from some of the ground cover competition. All species in this mix appeared to be compatible and should grow into a valuable tree stand. This study shows that this reforestation approach is quite viable for restoring native hardwoods, except that commonly used ground cover could compromise reforestation success.

Aethomys chrysophilus (Rodentia: Muridae)

Abstract The genus Aethomys currently includes 11 species, but recent evidence indicates a need for taxonomic revision of the genus. Aethomys chrysophilus (De Winton, 1897) is a muroid rodent commonly called the red veld rat. A medium-sized rodent with a long, sparsely haired tail, A. chrysophilus is largely parapatric with its sibling species, A. ineptus, and in areas of co-occurrence, determination of chromosome number, mitochondrial DNA analysis, or morphology of spermatozoa are required to distinguish A. chrysophilus from A. ineptus. Endemic to Africa, A. chrysophilus is found in savanna–woodland habitats that include varying combinations of grass–herbaceous ground cover, shrub understory, and miombo or mopane woodlands. It is not of special conservation concern.

Ruffed grouse brood habitat use in a mixed hardwood forest: Implications for forest management in the Appalachians

Brood habitat quality and availability may be a limiting factor for ruffed grouse ( Bonasa umbellus) populations in the central and southern Appalachians. We measured brood habitat characteristics at forest stand and microhabitat scales in western North Carolina. From 2000 to 2004, we monitored radiotagged females with broods ( n = 36) from hatch to 5 weeks post-hatch. We measured habitat characteristics and invertebrates at 186 brood locations and 186 paired, random locations. Brood sites had greater percent herbaceous ground cover, greater percent vertical cover 0–2 m, greater density of midstory stems <11.4 cm DBH, and greater invertebrate density compared with random sites. Seventeen broods survived the 5-week post-hatch period and were available for home range and second order habitat preference analysis. Mean 75% kernel home range was 24.3 ha (±4.0 S.E.). Top-ranked habitats for relative preference were mixed hardwoods in the 0–5, 6–20, and >80-year age classes, forest roads, and edges of maintained wildlife openings. Broods often were associated with managed stands. From this information, we recommend forest management prescriptions to enhance Appalachian ruffed grouse brood habitat.

Ruffed grouse brood habitat selection at multiple scales in Pennsylvania: implications for survival

Declines in ruffed grouse ( Bonasa umbellus (L., 1766)) populations in the central and southern Appalachians may be linked to low brood survival. Therefore, managing for high-quality brood habitat could improve grouse numbers. Understanding how brood habitat selection affects survival and the spatial scale at which this occurs is therefore fundamental to developing effective habitat management strategies. From 1999–2002, we monitored 38 broods for 5 weeks post hatch and estimated utilization distributions (n = 28), site-scale habitat use (n = 21), and daily survival rate (mean = 0.966, range = 0.920–0.997, and n = 19). Relative to available habitat, broods selected sites with greater herbaceous ground cover and higher small (&lt;2.5 cm diameter at breast height, DBH) stem densities and landscapes containing higher proportions of road and young deciduous forest. Herbaceous ground cover provided arthropod prey and concealment from predators and was a primary factor driving habitat selection. High stem densities and early successional habitats provided increased security, but were only used if adequate ground cover was present. Broods strongly selected roads and experienced higher survival near edges. However, higher road densities were associated with lower survival at the landscape scale. This pattern reflects the differential scale at which grouse and their predators respond to edge.

Wolf, &lt;em&gt;Canis lupus&lt;/em&gt;, Den Site Selection in the Rocky Mountains

Because mortality of Wolves, Canis lupus, is highest during the first six months of life, den site selection may affect reproductive success of Wolf populations. We studied fine-scale denning habitat selection (within 100 m of den site) by comparing field-measured characteristics of 22 dens in Idaho, Montana, and Alberta with 22 paired random contrast locations within pack home ranges. In order of importance, Wolves denned in areas with greater canopy cover, hiding cover, herbaceous ground cover, and woody debris, and were closer to water than paired random sites. Thus Wolves may select den sites for physical protection and available water. We also studied coarse-scale denning habitat selection by comparing 35 Wolf dens with 35 paired contrast locations in Idaho, Montana, and Wyoming with respect to six remotely-sensed variables (elevation, slope, coniferous forest cover, solar radiation, distance to water, and distance to roads). Although these variables did not differ (univariate P &gt; 0.10) between den and contrast locations, a Mahalanobis-distance model using four remotely-sensed variables (slope, elevation, coniferous forest cover, and solar radiation) suggested &gt; 85% of dens would occur in potential denning habitat occupying &lt; 12% of the Wolf recovery areas in the northern Rocky Mountains. This model may be useful for identifying likely den locations in areas not yet occupied by Wolves. Wolf core use areas, including den areas, showed higher intensity of use throughout the year when compared to the entire territory.

Late Pliocene grassland from Olduvai Gorge, Tanzania

The Olduvai fossil plants documented by us in this paper are the first direct evidence for open grassland in the late Neogene of Africa based on macroplant remains. Silicified remains of herbaceous ground cover are exceptionally well preserved in situ within Late Pliocene sediments below the initial pyroclastic ash surge unit of Tuff IF in the uppermost part of Bed I, Olduvai Gorge, northern Tanzania. Published radiometric and palaeomagnetic dates place this grass layer between 1.839 + 0.005 Ma and 1.785 + 0.01 Ma. Exposed at localities on the south side of the Gorge this herbaceous ground cover grew on a floodplain developed on a dried out lake bed, following pronounced lake retreat of saline–alkaline palaeo-Lake Olduvai during a developing dry climatic phase. Sheathed basal culms, rhizomes and roots are interpreted as those of one or more small mat-forming grasses or less likely, sedges. Small dicotyledonous herbs were probably also present. The proximity of adjacent plants indicates a relatively dense ground cover. Roots extended at least 8 cm below the ground surface. Aerial parts of the plants were absent or were not preserved when the weathered basal culms were covered by a thin layer of brown waxy clay, followed by fallout of pyroclastic ash. Both units were mostly eroded away prior to emplacement of a wet, cool pyroclastic surge which then buried and preserved in situ remnants of the herbaceous ground cover. Preservation of the semi-woody rhizomes implies well-drained soils, otherwise the plant material would have quickly rotted. Collections from discontinuous exposures indicate the grassland covered an area of at least a few hectares. This open grassland would have provided grazing for the Late Pliocene fauna.

Seasonal Use of Recently Fenced Agricultural Riparian Habitat by Avifauna in Pennsylvania

Streambank fencing is increasingly used to exclude livestock from riparian corridors and to enhance biological communities. Our study examined vegetative change and avian-community use of recently fenced agricultural habitat. We conducted strip-transect surveys to census bird communities, line-transect and plot surveys to assess vegetation, and intensive nest monitoring to gauge use and reproductive success across 12 fenced riparian sites in southwestern Pennsylvania. Selected sites varied in age from 3 to 8 years since fencing and averaged 21 m in width. We found avian use was significantly greater in spring than in fall across our fenced sites. We determined that canopy cover, shrub cover, and herbaceous ground cover could predict various attributes of the avian community present within the fenced riparian areas. Our results also suggest that the avian community has greater species richness within sites containing greater habitat complexity, and that these sites are important breeding and nesting areas. Among the 145 nests monitored, 38% successfully fledged young. We found no differences in distance to corridor edge between successful nests and nests that failed. Our study confirms that riparian renovation efforts do have conservation value for both migratory and resident birds.

A Comparison of Planted Loblolly Pine (Pinus taeda) Growth in Areas Receiving Different Levels of Establishment Regime Intensity

Management intensity of southeastern US pine (Pinus spp.) plantations has increased during past decades, emphasizing timber production. Managers need more information about tree growth responses to different establishment intensities to successfully meet their economic and ecological objectives. We established a comparison of five loblolly pine (P. taeda) plantation establishment regimes in the Mississippi Lower Coastal Plain (LCP, n = 4), using a gradient of mechanical and chemical site preparation and herbaceous weed control intensities. Treatments varied from “low intensity” to “high intensity” and were expected to produce a gradient in vegetative and pine growth response. We monitored herbaceous and woody ground cover, woody stem density, pine survival, and pine growth during years one and two post-treatment (2002 and 2003). Herbaceous cover, woody cover, and woody stem density decreased as treatment intensity increased. Pine survival was less on Treatment 5 and decreased slightly on all treatments during 2003. Pine height and diameter increased as treatment intensity increased, except for the treatment with no mechanical preparation, indicating the importance of subsoiling and bedding in the LCP. After two growing seasons, a combination of mechanical and chemical site preparation followed by one or two years of broadcast herbaceous weed control maximized pine growth.

Forest Stand Characteristics Altered by Restoration Affect Western Bluebird Habitat Quality

Abstract Forest managers are setting Ponderosa pine (Pinus ponderosa) forests in the southwestern United States on a trajectory toward a restored ecosystem by reducing tree densities and managing with prescribed fire. The process of restoration dramatically alters forest stands, and the effects of these changes on wildlife remain unclear. Our research evaluated which aspects of habitat alteration from restoration treatments may be affecting the habitat quality of Western Bluebird (Sialia mexicana), an insectivorous songbird whose populations are declining. Habitat loss resulting from fire‐suppression activities may be partially responsible for their population declines; thus, the bluebird is a good representative species for assessing how the reconstruction of presuppression forest conditions can affect wildlife. We measured habitat variables at 63 successful and 19 unsuccessful Western Bluebird nests in 1999–2001 and 2003. We compared habitat models that represented bluebird biology and habitat changes from restoration. Two models of nest success that included (1) an increased herbaceous and bare ground cover and (2) increased Gambel oak (Quercus gambelii) densities and reduced Ponderosa pine densities were most supported by the data. Increased herbaceous ground cover and Gambel oak density likely represent improved invertebrate assemblages and thus improved forage abundance for nesting bluebirds. Lower Ponderosa pine densities may provide bluebirds with open perches from which to hunt and thereby improve the availability of invertebrates as a food source. We also provide a landscape‐scale example of changes to bluebird habitat quality from treatments, which we recommend as a useful tool in restoration planning.