Bird Utilization of Woodland Habitat in the Eastern Quarter of South Dakota

Bird utilization of narrow, riparian woodland; riparian; block-like, tree claim; and linear, single-row windbreak habitats in the eastern quarter of South Dakota were studied during the spring migration, reproductive, and winter seasons. The relative importance of these three habitats and multi-row shelterbelt habitat was evaluated using bird species diversity (BSD), bird population density, and habitat preferences of individual bird species. Cluster analysis delineated distinctive vegetation cover types in each of the three habitats studied. Bird communities associated with each cover type were tabulated for comparison purposes and predication capabilities. Multiple regression analysis predicted physical and vegetation features of each habitat type that correlated with BSD, population density, and density of common nesting and wintering birds. Maintenance of BSD at present levels in woodlands of the eastern quarter of South Dakota is dependent primarily upon preservation of riparian woodland habitat, and secondly tree claim habitat. Shelterbelt and windbreak habitats supported bird diversities lower (p \u3c 0.05) than riparian woodland or tree claim habitats during all seasons studied, but supported significantly higher ( p \u3c 0.05 level) population densities during all seasons except winter. Single-row windbreaks were not suitable for supporting winter bird populations. Sparse stands of trees (± = 32.2 trees/0.4 ha) with occasional shrubs (± = 54.0 m3 /0.4 ha) supported all but one of the bird specific associated with dense tree stands (± = 144.2 trees/0.4 ha) with a moderately developed shrub layer (± = 678.8 m3/ 0.4 ha) in riparian woodlands during the reproductive season. Elimination of the shrub layer and loss of tree vigor, however, caused a decrease in number of species using tree claim habitat. Unique transients occurred in tree claim habitat. Unique transients occurred in tree claims with dense tree stands (± = 2126.0 trees/0.4ha) and developed shrub layers (± = 1082.6m3/0.4 ha) and in the denser riparian woodland study plots during spring migration. Maintaining maximum bird diversity in riparian woodland habitat during spring migration and reproductive seasons was most dependent on the area of habitat present. Minimum plot sizes of 6.0 ha and 5.9 ha were predicated to support 95% of the maximum BSD supported by riparian woodland habitat during the spring migration and reproductive seasons, respectfully. [See more in text

Effect of lianas on forest-level tree carbon accumulation does not differ between seasons: Results from a liana removal experiment in Panama

1. Lianas are prevalent in Neotropical forests, where liana-tree competition can be intense, resulting in reduced tree growth and survival. The ability of lianas to grow relative to trees during the dry season suggests that liana-tree competition is also strongest in the dry season. If correct, the predicted intensification of the drying trend over large areas of the tropics in the future may therefore intensify liana-tree competition, resulting in a reduced carbon sink function of tropical forests. However, no study has established whether the liana effect on tree carbon accumulation is indeed stronger in the dry than in the wet season. 2. Using six years of data from a large-scale liana removal experiment in Panama, we provide the first experimental test of whether liana effects on tree carbon accumulation differ between seasons. We monitored tree and liana diameter increments at the beginning of the dry and wet season each year to assess seasonal differences in forest-level carbon accumulation between removal and control plots. 3. We found that median liana carbon accumulation was consistently higher in the dry (0.52 Mg C ha-1 yr-1) than the wet season (0.36 Mg C ha-1 yr-1), and significantly so in three of the years. Lianas reduced forest-level median tree carbon accumulation more severely in the wet (1.45 Mg C ha-1 yr-1) than the dry (1.05 Mg C ha-1 yr-1) season in all years. However, the relative effect of lianas was similar between the seasons, with lianas reducing forest-level tree carbon accumulation by 46.9% in the dry and 48.5% in the wet season. 4. Synthesis: Our results provide the first experimental demonstration that lianas do not have a stronger competitive effect on tree carbon accumulation during the dry season. Instead, lianas compete significantly with trees during both seasons, indicating a large negative effect of lianas on forest-level tree biomass increment regardless of seasonal water stress. Longer dry seasons are unlikely to impact liana-tree competition directly; however, the greater liana biomass increment during dry seasons may lead to further proliferation of liana biomass in tropical forests, with consequences for their ability to store and sequester carbon

Long‐Term Effects of Tree Expansion and Reduction on Soil Climate in a Semiarid Ecosystem

In sagebrush ecosystems, pinyon and juniper tree expansion reduces water available to perennial shrubs and herbs. We measured soil water matric potential and temperatures at 13–30 and 50–65 cm soil depths in untreated and treated plots across a range of environmental conditions. We sought to determine the effects of tree expansion, tree reduction treatments, and expansion phase at time of treatment over 12–13 yr post‐treatment. Because the effects of tree reduction on vegetation can vary with the soil temperature/moisture regime, we also analyzed differences in soil climate variables between the mesic/aridic‐xeric and frigid/xeric regime classifications for our sites. Growing conditions during all seasons except spring were greatly limited by lack of available water, low temperatures, or both. Advanced tree expansion reduced wet days (total hours per 24 hr when hourly average soil water matric potential \u3e−1.5 MPa), especially in early spring. Fire and mechanical tree reduction increased wet days and wet degree days (sum of hourly soil temperatures \u3e0°C when soil is wet per 24 hr) compared with no treatment for most seasons. Burning resulted in higher soil temperatures than untreated or mechanically treated woodlands. Tree reduction at advanced expansion phases increased wet days in spring more than when implemented at earlier phases of expansion. Added wet days from tree reduction were negatively associated with October through June precipitation and vegetation cover, rather than time since treatment, with more wet days added on drier sites and years. The longer period of water availability in spring supports increased growth and cover of not only shrubs and perennial herbs, but also invasive weeds on warmer and drier sites, for many years after tree reduction. We found that sites classified as mesic/aridic‐xeric had warmer soil temperatures all seasons and were drier in spring and winter than sites classified as frigid/xeric. Land managers should consider reducing trees at earlier phases of expansion or consider revegetation when treating at advanced phases on these warmer and drier sites that lack perennial herb potential

Irrigated and unirrigated eastern cottonwood and water oak in a short rotation fiber system on a former agricultural site

Abstract-Seedlings from an open-pollinated family of water oak (Quercus L) and cuttings from clones of eastern cottonwood (Populus Bartr. ex Marsh) and hybrid poplar (P. Torr. and Gray X P. Bartr. ex Marsh.) were tested on a Perry clay soil in east central Arkansas (St Francis County). The test site received a preplant application of 100 pounds of nitrogen per acre and weed control for two growing seasons. Unirrigated and irrigated test families were monitored for survival and growth through age two. Some Populus clones survived best when irrigated and other clones when unirrigated. All test material exhibited significantly more volume per planted tree when irrigated. After two growing seasons, irrigated exceeded unirrigated saplings with enhanced mean performance for height, diameter, and volume per planted tree of 3.1 feet, 0.6 inches and 19.9 respectively. Hybrid poplars exhibited more uniform early growth

Baldcypress Restoration in a Saltwater Damaged Area of South Carolina

Baldcypress (Taxodium distichum (L.) Rich.) seed was collected in 1992 from nine different estuarine areas in the southeastern United States (Winyah Bay, SC, Ogeechee and Altmaha Rivers in GA, Loftin Creek, FL, Ochlockonee River FL, Mobile Bay, AL, West Pearl River, LA, Bayou LaBranche, LA, and Lake Chicot, LA) and planted in Clemson University\u27s Hobcaw nursery in the spring of 1993. Germination ranged from a low of 16 percent for seed from FL to 58 percent for seed from NC. Seedlings were grown in the nursery for two growing seasons, lifted, and planted in an area killed by saltwater introduced by Hurricane Hugo\u27s (1989) storm surge. Half of the seedlings were protected with tree shelters. Seedlings averaged 122 cm tall upon planting. Survival after 6 years was 99 percent. Height growth of seedlings in tree shelters was significantly higher than those not in tree shelters for each year except during year 3. Among the seed sources, seedlings from the Loftin Creek, FL source have shown greatest growth, with and without protection, for all growing seasons except the first year. After 6 years, average height of tree-shelter protected seedlings was 393 cm while the average height of non-protected seedlings was 281 cm. Tree-shelters increased early growth of seedlings, but once they emerged from the tree-shelter, growth differences between shelter and no-shelter treatments decreased and seems to be more related to the degree of deer herbivory experienced by unprotected seedlings

A Survey of Avian Influenza in Tree Sparrows in China in 2011

Tree sparrows (Passer montanus) are widely distributed in all seasons in many countries. In this study, a survey and relevant experiments on avian influenza (AI) in tree sparrows were conducted. The results suggested that the receptor for avian influenza viruses (AIVs), SAα2,3Gal, is abundant in the respiratory tract of tree sparrows, and most of the tree sparrows infected experimentally with two H5 subtype highly pathogenic avian influenza (HPAI) viruses died within five days after inoculation. Furthermore, no AIVs were isolated from the rectum eluate of 1300 tree sparrows, but 94 serological positives of AI were found in 800 tree sparrows. The serological positives were more prevalent for H5 subtype HPAI (94/800) than for H7 subtype AI (0/800), more prevalent for clade 2.3.2.1 H5 subtype HPAI (89/800) than for clade 2.3.4 (1/800) and clade 7.2 (4/800) H5 subtype HPAI, more prevalent for clade 2.3.2.1 H5 subtype HPAI in a city in southern China (82/800) than in a city in northern China (8/800). The serological data are all consistent with the distribution of the subtypes or clades of AI in poultry in China. Previously, sparrows or other passerine birds were often found to be pathogenically negative for AIVs, except when an AIV was circulating in the local poultry, or the tested passerine birds were from a region near waterfowl-rich bodies of water. Taken together, the data suggest that tree sparrows are susceptible to infection of AIVs, and surveys targeting sparrows can provide good serological data about the circulation of AIVs in relevant regions

Effect of cutting diameter and hormonal application on the propagation of Ficus roxburghii Wall. through branch cuttings

Fruit gathering from Ficus roxburghii Wall., a multipurpose tree,hinders its regeneration through seed. The present study was undertaken to propagate this species using branch cuttings treated with different hormones in two different seasons: rainy-July and spring-March. In both seasons (rainy and spring), large sized (1.25-2.5 cm diameter) cuttings resulted in statistically higher growth of all the studied parameters than that of small sized (< 1.25 cm diameter) cuttings, except the number of shoots in both the seasonsand number of lateral roots in rainy season. The effect of hormonal treatments(Indole-acetic acid, Indole-butyric acid and Naphthyl-acetic acid)was also significant on all the studied parameters in both the study seasons except in the case of number of shoots in rainy season where the influence was not-significant. The interaction large size x IBA 100 ppm resulted in significantly better growth of the studied parameters in both seasons except for the number of lateral roots, number of shoots, shoot length and number of leaves in rainy season. This study implies that species is amenable to cloning with different hormonal treatments. In general, it was observed that growth and development of cuttings was better in spring than the rainy season.Therefore, for the successful propagation of Ficus roxburghii, largesized cuttings are to be treated with IBA 100 ppm and be planted in spring

Assessing Environmental Control of Sap Flux of Three Tree Species Plantations in Degraded Hilly Lands in South China

Prerequisite for selection of appropriate tree species in afforestation programs is to understand their water use strategy. Acacia mangium Willd., Schima wallichii Choisy, and Cunninghamia lanceolata (Lamb.) Hook are the three main vegetation restoration pioneer species in southern China, but no comparative research on the water use strategy of these three tree species have been reported. Our objective was to gain a detailed understanding of how photosynthetically active radiation (PAR), vapor pressure deficit (VPD), and soil water content (SWC) at different soil depths control the sap flux density (Js) in the dry and wet seasons. We measured the Js of these three tree species by using the thermal dissipation method in low subtropical China. We found that both S. wallichii and C. lanceolata differed clearly in their stomatal behavior from one season to another, while A. mangium did not. The canopy conductance per sapwood area of S. wallichii and C. lanceolata was very sensitive to VPD in the dry season, but not in the wet season. The Js of A. mangium was negatively correlated to SWC in all soil layers and during both seasons, while the other two species were not sensitive to SWC in the deeper layers and only positively correlated to SWC in dry season. Our results demonstrate that the three species have distinct water use strategies and may therefore respond differently to changing climate

Assessing Environmental Control of Sap Flux of Three Tree Species Plantations in Degraded Hilly Lands in South China

Prerequisite for selection of appropriate tree species in afforestation programs is to understand their water use strategy. Acacia mangium Willd., Schima wallichii Choisy, and Cunninghamia lanceolata (Lamb.) Hook are the three main vegetation restoration pioneer species in southern China, but no comparative research on the water use strategy of these three tree species have been reported. Our objective was to gain a detailed understanding of how photosynthetically active radiation (PAR), vapor pressure deficit (VPD), and soil water content (SWC) at different soil depths control the sap flux density (Js) in the dry and wet seasons. We measured the Js of these three tree species by using the thermal dissipation method in low subtropical China. We found that both S. wallichii and C. lanceolata differed clearly in their stomatal behavior from one season to another, while A. mangium did not. The canopy conductance per sapwood area of S. wallichii and C. lanceolata was very sensitive to VPD in the dry season, but not in the wet season. The Js of A. mangium was negatively correlated to SWC in all soil layers and during both seasons, while the other two species were not sensitive to SWC in the deeper layers and only positively correlated to SWC in dry season. Our results demonstrate that the three species have distinct water use strategies and may therefore respond differently to changing climate