Search USGS⌕ Search

SEARCH · Search USGS

Results for “Weeds”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources
USGS2002

Water-quality and physical characteristics of streams in the Treyburn development area of Falls Lake watershed, North Carolina, 1994–98

Treyburn is a 5,400-acre planned, mixed-use development in the upper Neuse River Basin of North Carolina. The development, which began in 1986, is located in the Falls Lake watershed near three water-supply reservoirs-Lake Michie to the north, Falls Lake to the southeast, and Little River Reservoir to the west. A study began in 1988 to determine the water-quality characteristics of surface waters in and around the Treyburn development area. Data to characterize water quality at five different sites were collected from July 1994 through September 1998. Data from a previous study are available for some sites for the period 1988–93. The sites were selected to characterize water quality and quantity in and near the Treyburn development and included an undeveloped basin, a relatively small basin containing single-family residences and a golf course, a basin downstream from the western part of the development with some industrial land use, and two basins unaffected by the development where agricultural land is being converted to urban and forested land use. Suspended-sediment concentrations ranged from less than 1 to 581 milligrams per liter and were fairly uniform among the five sites. Median suspended-sediment concentrations ranged from 12 to 21 milligrams per liter. Few concentrations of metals and trace elements, except aluminum, iron, and manganese, exceeded the laboratory reporting levels or water-quality criteria. At one site, concentrations of silver exceeded both the action level and the reporting level; copper was detected at each site and exceeded the action level of 7 micrograms per liter at one site. The lowest range and median concentrations of total organic nitrogen, nitrate, ammonia, total phosphorus, and orthophosphorus occurred in the relatively undisturbed, forested site. The maximum concentration of organic nitrogen (1.97 milligrams per liter) occurred at one of the sites unaffected by the Treyburn development where agricultural land is being converted to urban land use. At all sites, ammonia concentrations ranged from less than 0.02 to 0.36 milligram per liter, and median concentrations were near the reporting level. Nitrate concentrations ranged from less than 0.05 to 0.80 milligram per liter. Phosphorus concentrations at all of the Treyburn study sites were low compared to phosphorus concentrations that typically exceed 0.1 milligram per liter at sites sampled nationally for the U.S. Geological Survey National Water-Quality Assessment Program, including the Albemarle-Pamlico study area in North Carolina. Total phosphorus concentrations ranged from less than 0.01 to 0.87 milligram per liter, and orthophosphorus concentrations ranged from less than 0.01 to 0.76 milligram per liter as phosphorus. The maximum concentrations of total phosphorus and orthophosphorus occurred at the Treyburn residential and golf-course site, likely as a result of the fertilizer applications associated with these two types of land use. Of the 119 different pesticides tested, 11 were detected in concentrations that exceeded the laboratory reporting levels, though in very low concentrations. Water samples from the residential and golf-course site contained the greatest number of pesticides (10). Five of six samples collected at this site had detectable concentrations of simazine, atrazine, and pendimethalin-all herbicides used to control weeds in crops or turf. Channel geometry was assessed at eight sites in the study area in February 1997. These sites were separated into three groups based on mean bank angle and mean channel width-to-depth ratios. Channel gradient ranged from 0.04 to 1.63 percent, and mean cross sectional area ranged from 31 to 1,227 square feet. Three macroinvertebrate samples were collected from each of 10 sites. These three samples were from areas designated as richest targeted habitats, depositional targeted habitats, and qualitative multitargeted habitats. Over 230 taxa were identified fromthese 10 sites. The North Carolina Biotic Indices ranged from 4.98 (excellent) to 6.82 (fair). River sites tended to have higher total taxa richness (91-108) than did the small, intermittent streams (49–84) or the midsize Mountain Creek (85). Intermittent streams represent fairly hostile environments for most aquatic organisms. Samples from richest targeted habitats typically were more than twice as rich as samples from depositional targeted habitats and represented from 50 to 75 percent of the taxa found at each site (mean of 62 percent). The industrial site lacked many of the mayfly taxa that were present at the undeveloped site. Mayflies are very sensitive to metals contamination, and their absence may indicate a possible problem. The supporting chemical information is not available for the industrial site, and additional study would be necessary to substantiate this possibility. The two sites with residential and golf-course land use tended to support more different types of sensitive invertebrates (that is, mayflies, stoneflies, and caddis flies) than did the forested/residential site, though the abundances of these taxa were very similar. Land-use effects were not evident based on a comparison among these sites. Indirect gradient analysis was used to determine patterns in the distribution of invertebrates and to examine the relations between these patterns and physical and chemical site characteristics determined in this study. This analysis supports the contention that the dominant factors accounting for the distribution of benthic invertebrates are associated with natural factors, such as basin size, rather than land use. Constituent loads at five study sites were calculated for nutrients, suspended sediment, and total organic carbon. The median annual total nitrogen yield ranged from 0.635 to 1.63 tons per square mile. The median annual phosphorus yield ranged from 0.046 to 0.619 ton per square mile, and the median annual orthophosphate yield ranged from 0.022 to 0.379 ton per square mile. Orthophosphate accounted for more than half of the phosphorus yield at the residential and golf-course site. The maximum suspended-sediment yield was 422 tons per square mile, and the minimum yield was 32 tons per square mile. The suspended-sediment yield at one of the sites unaffected by the Treyburn development where agricultural was being converted to urban land use was high compared to other forested basins in the Piedmont of North Carolina. Total organic carbon data sufficient for estimating loads were available at three of the five sites. Of these three sites, the undeveloped site had substantially more organic carbon yield than the other two sites. The only significant water-quality trend (alpha=0.05) was a downward trend for total nitrogen and organic nitrogen at the undeveloped site. The trend slope was small, only 0.019 milligram per liter as nitrogen or less than 9 percent of the median organic nitrogen concentration. No trend was observed for nitrite plus nitrate or for ammonia, indicating that the downward trend in total nitrogen was due only to organic nitrogen.

North Carolina↗
USGS2009

Uncertainty in georeferencing current and historic plant locations

With shrinking habitats, weed invasions, and climate change, repeated surveys are becoming increasingly important for rare plant conservation and ecological restoration. We often need to relocate historical sites or provide locations for newly restored sites. Georeferencing is the technique of giving geographic coordinates to the location of a site. Georeferencing has been done historically using verbal descriptions or field maps that accompany voucher collections. New digital technology gives us more exact techniques for mapping and storing location information. Error still exists, however, and even georeferenced locations can be uncertain, especially if error information is not included with the observation. We review the concept of uncertainty in georeferencing and compare several institutional database systems for cataloging error and uncertainty with georeferenced locations. These concepts are widely discussed among geographers, but ecologists and restorationists need to become more aware of issues related to uncertainty to improve our use of spatial information in field studies. ?? 2009 by the Board of Regents of the University of Wisconsin System.

Ecological Restoration↗
USGS2024

Vegetation responses to large dam removal on the Elwha River, Washington, USA

Large dam removal can trigger changes to physical and biological processes that influence vegetation dynamics in former reservoirs, along river corridors downstream of former dams, and at a river’s terminus in deltas and estuaries. We present the first comprehensive review of vegetation response to major fluvial disturbance caused by the world’s largest dam removal. After being in place for nearly a century, two large dams were removed along the Elwha River, Washington, USA, between 2011 and 2014. The exposure, erosion, transport, and deposition of large volumes of sediment and large wood that were impounded behind the dams created new fluvial surfaces where plant colonization and growth have occurred. In the former reservoirs, dam removal exposed ~290 ha of unvegetated sediment distributed on three main landforms: valley walls, high terraces, and dynamic floodplains. In addition to natural revegetation in the former reservoirs, weed control and seeding and planting of desirable plants influenced vegetation trajectories. In early years following dam removal, ~20.5 Mt of trapped sediment were eroded from the former reservoirs and transported downstream. This sediment pulse, in combination with transport of large wood, led to channel widening, an increase in gravel bars, and floodplain deposition. The primary vegetation responses along the river corridor were a reduction in vegetated area associated with channel widening, plant establishment on new gravel bars, increased hydrochory, and altered plant community composition on gravel bars and floodplains. Plant species diversity increased in some river segments. In the delta, sediment deposition led to the creation of ~26.8 ha of new land surfaces and altered the distribution and dynamics of intertidal water bodies. Vegetation colonized ~16.4 ha of new surfaces: mixed pioneer vegetation colonized supratidal beach, river bars, and river mouth bars, and emergent marsh vegetation colonized intertidal aquatic habitats. In addition to the sediment-dominated processes that have created opportunities for plant colonization and growth, biological processes such as restored hydrochory and anadromous fish passage with associated delivery of marine-derived nutrients may influence vegetation dynamics over time. Rapid changes to landforms and vegetation growth were related to the large sediment pulse in the early years following dam removal, and the rate of change is expected to attenuate as the system adjusts to natural flow and sediment regimes.

Washington↗
USGS2022

Scanning the horizon for invasive plant threats using a data-driven approach

Early detection and eradication of invasive plants are more cost-effective than managing well-established invasive plant populations and their impacts. However, there is high uncertainty around which taxa are likely to become invasive in a given area. Horizon scanning that combines a data-driven approach with rapid risk assessment and consensus building among experts can help identify invasion threats. We performed a horizon scan of potential invasive plant threats to Florida, USA—a state with a high influx of introduced species, conditions that are generally favorable for plant establishment, and a history of negative impacts from invasive plants. We began with an initial list of 2128 non-native plant taxa that are known invaders or crop pests. We built on previous invasive species horizon scans by developing data-based criteria to prioritize 100 taxa for rapid risk assessment. The semi-automated prioritization process included selecting taxa “on the horizon” (i.e., not yet in the target location and not on a noxious weed list) with climate matching, naturalization history, “weediness” record, and global commonness. We derived overall invasion risk scores with rapid risk assessment by evaluating the likelihood of each of the taxa arriving, establishing, and having an impact in Florida. Then, following a consensus-building discussion, we identified six plant taxa as high risk, with overall risk scores ranging from 75 to 100 out of a possible 125. The six taxa are globally distributed, easily transported to new areas, found in regions with climates similar to Florida’s, and can impact native plant communities, human health, or agriculture. Finally, we evaluated our initial and final lists for potential biases. Assessors tended to assign higher risk scores to taxa that had more available information. In addition, we identified biases towards four plant families and certain geographical regions of origin. Our horizon scan approach identified taxa conforming to metrics of high invasion risk and used a methodology refined for plants that can be applied to other locations.

NeoBiota↗
USGS2022

Annual summer submersed macrophyte standing stocks estimated from long-term monitoring data in the Upper Mississippi River

System-scale restoration efforts within the Upper Mississippi River National Wildlife and Fish Refuge have included annual monitoring of submersed aquatic vegetation (SAV) since 1998 in four representative reaches spanning ∼ 440 river kilometers. We developed predictive models relating monitoring data (site-scale SAV abundance indices) to diver-harvested SAV biomass, used the models to back-estimate annual standing stock biomass between 1998 and 2018, and compared biomass estimates with previous abundance measures. We modeled two morphologically distinct groups of SAV with differing sampling efficiencies and estimated each separately: the first category included only wild celery Vallisneria americana, which has long, unbranched leaves and dominates lotic environments, while the second category included 17 branched morphology species (e.g., hornwort Ceratophyllum demersum and Canadian water weed Elodea canadensis ) and dominates lentic environments. Wild celery accounted for approximately half of total estimated total biomass in the four reaches, combined branched species accounted for half, and invasive species (Eurasian watermilfoil Myriophyllum spicatum and curly-leaf pondweed Potamogeton crispus ), a fraction of the branched species, accounted for < 1.5%. Site-scale SAV estimates ranged from 0 to 535 g·m −2 (dry mass). We observed increases in biomass in most areas between 1998 and 2009 and substantial increases (e.g., from < 10 g·m −2 to ∼ 125 g·m −2 ) in wild celery in extensive impounded areas between 2002 and 2007. Analyses also indicate a transitional period in 2007–2010 during which changes in biomass trajectories were evident in all reaches and included the start of a 9-y, ∼ 70% decrease in wild celery biomass in the southernmost impounded area. Biomass estimates provided new insights and illustrated scales of change that were not previously apparent using traditional metrics. The ability to estimate biomass from Long Term Resource Monitoring data improves conservation efforts through better understanding of changes in habitat and food resources for biota, improved goal setting for restoration projects and improved quantification of SAV-mediated structural effects such as anchoring of sediments and feedbacks with water quality.

Illinois, Iowa, Minnesota, Wisconsin↗
USGS2011

Structural and functional effects of herbicides on non-target organisms in aquatic ecosystems with an emphasis on atrazine

Herbicide use has increased dramatically around the world over the past 6 decades (Gianessi and Reigner, 2007). Few herbicides were in use in the 1950s. However, by 2001 approximately 1.14 billion kilograms of herbicides were applied globally for the control of undesireable vegetation in agricultural, silvicultural, lawncare, aquacultural, and irrigation/recreational water management activities (Kiely et al., 2004). Twenty-eight percent of the total mass of herbicides is applied in the United States, with the remaining 72 percent being applied elsewhere around the globe (Kiely et al., 2004). Herbicides represent 36% of global pesticide use, followed by insecticides (25%), fungicides (10%) and other chemical classes (Kiely et al., 2004). Agricultural production accounts for approximately 90% of herbicide use in the U.S. (Kiely et al., 2004). Gianessi and Reigner (2007) indicated that herbicides are routinely used on more than 90% of the area designated for large commercial crops including corn, soybeans, cotton, sugar beets, peanuts, and rice. Increased farm mechanization, technological advancements in production of inexpensive sources of inorganic nitrogen fertilizer (e.g., anhydrous ammonia), and conversion of forest, grassland, and wetland habitats to cropland has led to a tremendous increase in global food production over the past half-century. Herbicides have augmented advances in large-scale agricultural systems and have largely replaced mechanical and hand-weeding control mechanisms (Gianessi and Reigner, 2007). The wide-spread use of herbicides in agriculture has resulted in frequent chemical detections in surface and groundwaters (Gilliom, 2007). The majority of herbicides used are highly water soluble and are therefore prone to runoff from terrestrial environments. In additon, spray drift and atmospheric deposition can contribute to herbicide contamination of aquatic environments. Lastly, selected herbicides are deliberately applied to aquatic environments for controlling nuisance aquatic vegetation. Although aquatic herbicide exposure has been widely documented, these exposures are not necessarily related to adverse non-target ecological effects on natural communities in aquatic environments. This chapter evaluates the potential for effects of herbicides on the structure and function of aquatic envrionments at the population, community, and ecosystem levels of biological organization. In this manuscript I examine several critical aspects of the subject matter area: primary herbicides in use and chemical modes of action; the regulatory process used for registration and risk assessment of herbicides; data regarding non-target risks and the relative sensitivity of aquatic plants, inveretebrates, and fish to herbicides; and emerging areas of science regarding the potential for endocrine-disrupting effects of herbicides on aquatic vertebrates. Much of the focus of this paper is on atrazine due to the extensive database which exists regarding its fate and effects.

Book chapter↗
USGS2018

“Naturalness” in designated Wilderness: Long-term changes in non-native plant dynamics on campsites, Boundary Waters, Minnesota

Wilderness areas in the United States are preserved for their untrammeled naturalness and opportunities for unconfined recreation. The Boundary Waters Canoe Area Wilderness has these qualities, but long-term recreation visitation pressures on campsites can cause significant ecological changes. This article explores changes on campsites, specifically examining non-native plant ecology over 3 decades. The research replicates a 1982 study analyzing vegetation composition and cover on campsites and environmentally paired controls. Camping activities have removed substantial tree cover on campsites, altering their ecological conditions and perceived wilderness character. Over the span of 32 years, the number of non-native plant species found on campsites has not risen, although their mean relative cover has increased significantly and they have spread to more sites. Of the 23 non-native herbs and grasses found on the campsites, only Cirsium arvense is considered a noxious weed by the state of Minnesota. Other noninvasive, non-native plants fall into a gray area in the context of "naturalness" for an area protected as Wilderness because they provide some positive ecological services even as they degrade wilderness character. Thus, wilderness managers face a difficult challenge in coping with the long-term impacts of visitor use on wilderness conditions and character.

Minnesota↗
USGS1994

Relationship between resistance of salmonids to furunculosis and recovery of Aeromonas salmonicida from external mucus

Fish were sampled at the Ed Weed State Fish Hatchery (South Hero, Vermont, USA) in September 1992. Aeromonas salmonicida was common, with concentrations as high as 10 5 to 10 7 colony-forming units per gram of mucus, and readily recovered from most mucus samples obtained from furunculosis-sensitive populations of brook trout ( Salvelinus fontinalis ), lake trout ( Salvelinus namaycush ), and Atlantic salmon (Salmo salar) . The pathogen was the predominant microorganism and accounted for greater than 85% of the total number of bacteria isolated from the mucus of these fish. By comparison, A. salmonicida was recovered only from two rainbow trout ( Oncorhynchus mykiss ), and bacterial frequencies did not exceed 10 3 colony-forming units per gram of mucus. The pathogen was not recovered from the mucus of steelhead ( O. mykiss ) or Rome brown trout ( Salmo trutta ) selectively bred for resistance to furunculosis, even though there was widespread contagion throughout the hatchery and fish were cultured on a common, unprotected water supply.

Journal of Wildlife Diseases↗
USGS2018

Northern Great Plains

In the Northern Great Plains, the timing and quantity of both precipitation and runoff have important consequences for water supplies, agricultural activities, and energy production. Overall, climate projections suggest that the number of heavy precipitation events (events with greater than 1 inch per day of rainfall) is projected to increase. Moving forward, the magnitude of year-to-year variability overshadows the small projected average decrease in streamflow. Changes in extreme events are likely to overwhelm average changes in both the eastern and western regions of the Northern Great Plains. Major flooding across the basin in 2011 was followed by severe drought in 2012, representing new and unprecedented variability that is likely to become more common in a warmer world. The Northern Great Plains region plays a critical role in national food security. Among other anticipated changes, projected warmer and generally wetter conditions with elevated atmospheric carbon dioxide concentrations are expected to increase the abundance and competitive ability of weeds and invasive species, increase livestock production and efficiency of production, and result in longer growing seasons at mid- and high latitudes. Net primary productivity, including crop yields and forage production, is also likely to increase, although an increasing number of extreme temperature events during critical pollination and grain fill periods is likely to reduce crop yields. Ecosystems across the Northern Great Plains provide recreational opportunities and other valuable goods and services that are ingrained in the region’s cultures. Higher temperatures, reduced snow cover, and more variable precipitation will make it increasingly challenging to manage the region’s valuable wetlands, rivers, and snow-dependent ecosystems. In the mountains of western Wyoming and western Montana, the fraction of total water in precipitation that falls as snow is expected to decline by 25% to 40% by 2100 under a higher scenario (RCP8.5), which would negatively affect the region’s winter recreation industry. At lower-elevation areas of the Northern Great Plains, climate-induced land-use changes in agriculture can have cascading effects on closely entwined natural ecosystems, such as wetlands, and the diverse species and recreational opportunities they support. Energy resources in the Northern Great Plains include abundant crude oil, natural gas, coal, wind, and stored water, and to a lesser extent, corn-based ethanol, solar energy, and uranium. The infrastructure associated with the extraction, distribution, and energy produced from these resources is vulnerable to the impacts of climate change. Railroads and pipelines are vulnerable to damage or disruption from increasing heavy precipitation events and associated flooding and erosion. Declining water availability in the summer would likely increase costs for oil production operations, which require freshwater resources. These cost increases will either lead to lower production or be passed on to consumers. Finally, higher maximum temperatures, longer and more severe heat waves, and higher overnight lows are expected to increase electricity demand for cooling in the summer, further stressing the power grid. Indigenous peoples in the region are observing changes to climate, many of which are impacting livelihoods as well as traditional subsistence and wild foods, wildlife, plants and water for ceremonies, medicines, and health and well-being. Because some tribes and Indigenous peoples are among those in the region with the highest rates of poverty and unemployment, and because many are still directly reliant on natural resources, they are among the most at risk to climate change (e.g., Gamble et al. 2016, Cozzetto et al. 2013, Espey et al. 2014, Wong et al. 2014, Kornfeld 2016, Paul and Caplins 2016, Maynard 2014, USGCRP 2017)

Report↗
USGS1989

Atrazine Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review

The herbicide atrazine (2chloro4ethylamino6isopropylamino1,3,5triazine) is the most heavily used agricultural pesticide in North America. Domestically, more than 50 million kg are applied yearly to more than 25 million ha, primarily to control weeds in corn and sorghum crops. Atrazine residues have been detected in runoff from treated fields in lakes and streams at phytotoxic levels. Birds and mammals were comparatively resistant, with a low probability for atrazine accumulation and retention. Data are lacking on indirect effects of atrazine on wildlife granivores and insectivores. Direct effects to aquatic fauna occur at 94 micrograms/l, and higher; however, indirect effects may occur at 20 micrograms/l, and higher, partly through reduction of the food supply of herbivores, and partly through loss of macrophyte habitat. Ecological and toxicological aspects of atrazine in the environment are briefly reviewed, with special emphasis on fishery and wildlife resources.

Contaminant Hazard Reviews↗
USGS2006

Contaminant exposure and potential effects on terrestrial vertebrates residing in the National Capital Region network and Mid-Atlantic network

Part of the mission of the National Park Service is to preserve the natural resources, processes, systems, and associated values of its units in an unimpaired condition. Environmental contamination and pollution processes are well recognized stressors addressed by its management policies and plans. A recent study indicates that contemporary terrestrial vertebrate ecotoxicological data are lacking for 59 of 126 Park Service units located in coastal watersheds exhibiting serious water quality problems or high vulnerability to pollution. Based upon these findings, a more in-depth evaluation of contaminant threats and ecotoxicological data gaps related to terrestrial vertebrates was undertaken at 23 Inventory and Monitoring National Park units in National Capital Region and Mid-Atlantic Networks. Ecotoxicological data were compiled for each park unit through literature searches and meetings with Park Service personnel. Information on contemporary and on persistent legacy pollutants in air, water, soil, and terrestrial vertebrates (amphibians, reptiles, birds and mammals) were evaluated. To identify contaminant threats in proximity to the 23 Park Service study units, data was gathered on National Priority List Superfund sites, Section 303(d) Impaired Waterbodies, the number and relative toxicity of current use pesticides and herbicides, Toxic Release Inventory sites and discharge of priority pollutants, and Fish Consumption Advisories. A metric was derived that described the quality and quantity of existing data for each park, and in combination with known contaminant threats, park units in need of additional study were identified. Results demonstrated that over half of the Park Service study units are near Toxic Release Inventory sites discharging dioxins, polychlorinated biphenyls, lead or mercury into air or water, and fish consumption advisories are in effect at or near 22 of the 23 study units. Pesticide and herbicide use at the park units is minimal, with the exception of those units with significant agricultural leases. Despite highly regulated use, many of the pesticides and herbicides applied are believed to be highly toxic to amphibians, and some of the compounds are also highly toxic to birds. Only 70 reports were found that describe terrestrial vertebrate ecotoxicology data on or near the study units. Of the greater than 75,000 compounds in commerce in the United States, existing terrestrial vertebrate exposure and effects data in the pr esent study were limited to 58 legacy organochlorine pesticides, polychlorinated biphenyls and individual congeners, insecticides and rodenticides, metals, and some contemporary compounds (e.g., polybrominated diphenyl ether flame retardants, and alkylphenol and ethoxylate surfactants). Based upon these and other findings, ecotoxicological monitoring and research investigations of terrestrial vertebrates are warranted at several National Parks. These include Shenandoah National Park, Richmond National Battlefield, Chesapeake & Ohio Canal National Historic Park, Valley Forge National Historic Park, Hopewell Furnace National Historic Site, Monocacy National Battlefield, and Harpers Ferry National Historic Park. The types of investigations vary according to the species present at these parks and potential contaminant threats, but should focus on contemporary use pesticides and herbicides, polychlorinated biphenyls, mercury, lead, and perhaps, emerging contaminants including antibiotics, flame retardants, pharmaceuticals, and surfactants. Other management recommendations include additional training for natural resource staff members in the area of ecotoxicology, inclusion of terrestrial vertebrate contaminant monitoring and the Contaminant Assessment Process (U.S. Geological Survey Biomonitoring of Environmental Status and Trends Project) into the National Park Service Vital Signs Program, development of protocols for hand ling and toxicological analysis of dead or seemingly affected wildlife, consideration of some alternative methods and compounds for pest management and weed control, and use of non-toxic fishing tackle by visitors.

Maryland, Pennsylvania, Virginia↗
USGS2003

Synergy of agroforestry and bottomland hardwood afforestation

Afforestation of bottomland hardwood forests has historically emphasized planting heavy-seeded tree species such as oak (Quercus spp.) and pecan (Caryaillinoensis) with little or no silvicultural management during stand development. Slow growth of these tree species, herbivory, competing vegetation, and limited seed dispersal, often result in restored sites that are slow to develop vertical vegetation structure and have limited tree diversity. Where soils and hydrology permit, agroforestry can provide transitional management that mitigates these historical limitations on converting cropland to forests. Planting short-rotation woody crops and intercropping using wide alleyways are two agroforestry practices that are well suited for transitional management. Weed control associated with agroforestry systems benefits planted trees by reducing competition. The resultant decrease in herbaceous cover suppresses small mammal populations and associated herbivory of trees and seeds. As a result, rapid vertical growth is possible that can 'train' under-planted, slower-growing, species and provide favorable environmental conditions for naturally invading trees. Finally, annual cropping of alleyways or rotational pulpwood harvest of woody crops provides income more rapidly than reliance on future revenue from traditional silviculture. Because of increased forest diversity, enhanced growth and development, and improved economic returns, we believe that using agroforestry as a transitional management strategy during afforestation provides greater benefits to landowners and to the environment than does traditional bottomland hardwood afforestation.

Book chapter↗
USGS1997

Bottomland hardwood reforestation for neotropical migratory birds: Are we missing the forest for the trees?

Reforestation of bottomland hardwoods on lands managed for wildlife or timber production has historically emphasized planting heavy-seeded oaks (Quercus spp.). Although techniques have been developed for successful oak establishment, these plantings often require 5 or more years before establishing a 3-dimensional forest structure. We suggest that lands planted to fast-growing early-successional species, in combination with oaks, provide: (1) more expedient benefits to Neotropical migratory birds; (2) greater forest diversity; (3) more rapid economic return to landowners; and (4) enhanced public relations. Under good growing conditions, and with effective weed control, some fast-growing species can develop a substantial 3-dimensional forest structure in as few as 2 or 3 years. Forest-breeding Neotropical migratory birds use stands planted with early successional species several years before sites planted solely with oaks. Where desirable, succession to forests with a high proportion of oak species can be achieved on sites initially planted with fast-growing species through silvicultural management.

Wildlife Society Bulletin↗
USGS1967

Magruder Park Swamp

The last Tuesday in August, between five-thirty and seven in the evening, we zigzaged through this glorious jungle, attended by a family of Wood Pewees for whom we seemed to be stirring up a feast of flying insects. There was gentle background music by Mole Crickets. A few steps in from the playing field and we were out of sight in ten-foot-high Cattails. All through, we met -- as high as we, or higher--clumped Cinnamon Ferns, deep-rose Joe Pye Weed, and orange, pendent flowers of Jewelweed (first cousins to Balsam and Sultana). Here and there were soft, white spikes of Canadian Burnet, a rare plant hereabouts, and deep purple Ironweed. Dense-foliaged Hempweed climbed over bushes and up small trees, filling the air with its delicate fragrance. Arrowleaf Tear-thumb snatched at us with tiny prongs on its angled stems. Once in a while we tripped over huge sedge tussocks, half-hidden in the tangle. A few times we steered around a small bush of Poison Sumac. The next day We remembered seeing ninety kinds of plants on this hasty trip. Skunk Cabbage leaves recalled April, when a person, from the edge of the lawn, could see huge clumps of them all the way across the swamp. The sky had been washed by last week's downpours; scattered Gums were reddening; and Maples were getting ready for crimson beauty a month from now. There wasn't a mosquito! (Ed. Note.-The Hyattsville City Council is taking pains to preserve this interesting swamp.)

Prince Georges Post↗
USGS2006

Small clusters of fast-growing trees enhance forest structure on restored bottomland sites

Despite the diversity of trees in bottomland forests, restoration on bottomland sites is often initiated by planting only a few species of slow-growing, hard mast?producing trees. Although successful at establishing trees, these young forests are slow to develop vertical structure, which is a key predictor of forest bird colonization. Furthermore, when natural seed sources are few, restored sites may be depauperate in woody species. To increase richness of woody species, maximum tree height, and total stem density, I supplemented traditional plantings on each of 40 bottomland restoration sites by planting 96 Eastern cottonwood (Populus deltoides) and American sycamore (Platanus occidentalis) in eight clusters of 12 trees. First year survival of cottonwood stem cuttings (25%) and sycamore seedlings (47%) was poor, but survival increased when afforded protection from competition with weeds. After five growing seasons, 165 of these 320 supplemental tree clusters had at least one surviving tree. Vegetation surrounding surviving clusters of supplemental trees harbored a greater number of woody species, increased stem density, and greater maximum tree height than was found on paired restoration sites without supplemental trees. These increases were primarily accounted for by the supplemental trees.

Restoration Ecology↗
USGS2010

Baseline survey for rare plant species and native plant communities within the Kamehameha Schools 'Lupea Safe Harbor Planning Project Area, North Kona District, Island of Hawai'i

Kamehameha Schools, in conjunction with several federal, state, and private organizations, has proposed to conduct conservation management on approximately 5,340 ha (~13,200 acres) of land they own in the vicinity of Kīpukalupea in the North Kona District on the island of Hawai'i. The goal of this program is to restore and enhance the habitat to benefit native plant and animal populations that are currently, or were formerly, found in this site. The initial phase of this project has been focused on various activities including conducting baseline surveys for bird and plant species so Kamehameha Schools could develop a Safe Harbor Agreement (SHA) for the proposed project lands relative to the habitat management and species reintroduction efforts they would like to conduct in the Lupea Project area. This report summarizes methods that were used to collect field data on plant species and communities within the project area, and the results of that initial survey. The information was used to calculate baseline values for all listed threatened or endangered plant species found, or expected to be found, within the project area, and to design a monitoring program to assess changes in plant communities and rare plant species relative to management activities over the duration of the SHA. The Lupea Project area contains excellent examples of several high elevation native plant communities including montane dry forest and woodland, native subalpine shrubland, and native grassland. Between November 2003 and January 2004 we sampled plant communities and species along seven transects established through the project area. A total of 109 plant species were found during this survey, within the transect grid and in nearby areas. Forty-four of these plants are endemic species, 21 are indigenous species, 43 are introduced, and one species is believed to have been introduced to Hawai&bdquo;i by early Polynesian settlers. Only one federally listed Endangered plant, Asplenium peruvianum var. insulare , was found within the survey area. Additionally, we found one immature plant that may be Sicyos macrophyllus , a candidate species for listing. However, we were not able to make a definite determination of this species‟ identity since it did not have fruits or flowers. Finally, we documented four plant species within the survey area that have no official status designation but are considered to be rare and informally recognized as &ldquo;species of concern&rdquo; (SOC) as they appear to be declining in distribution and abundance statewide. These included Chamaesyce olowaluana, Eragrostis deflexa, Sisyrinchium acre, and Tetramolopium consanguineum . In addition to conducting field surveys, we performed a query on a spatial database developed by Dr. Jonathan Price of the University of Hawai&bdquo;i at Hilo which models the potential range of all native Hawaiian plant species based on historic observations and a set of environmental parameters. The potential species list for the Lupea Project area includes 47 taxa that we did not find during our surveys, as well as three other listed species that were not modeled by Price, but known from historic records in adjacent habitats. Some of these species are extremely rare or, in some cases have been locally extirpated. However, most of the plants that were predicted but not found during our surveys are expected to be located with additional searching, or may potentially recolonize the area following the elimination of ungulates and initiation of other restoration efforts. Forty-four introduced plant species were found within the survey area, seven of which are considered to be highly invasive. These include the grasses Pennisetum clandestinum and Pennisetum setaceum , vines Delairea odorata and Passiflora tarminiana , herbs Senecio madagascariensis and Verbascum thapsus , and the shrub Rubus niveus . Non-zero baseline values are proposed for the one listed plant species found within the Lupea Project area, one species that is a candidate for listing, and the four other rare species we found that may be considered for listing in the future. Additionally, a zero baseline is proposed for 23 other species that were predicted, but not found within the project area. These include 14 Endangered species, one Threatened species, two candidates for listing, and six species of concern. Subsequent monitoring of the site will be necessary to determine if the populations of these species have increased or decreased relative to their baseline values. It is presumed that the management activities Kamehameha Schools has proposed for this area, particularly removal of the ungulates and weed control, will provide a benefit to the habitat as a whole and allow for natural regeneration and maintenance of the all elements of the plant communities found there.

Hawaii↗
USGS2011

Design of forest bird monitoring for strategic habitat conservation on Kaua'i Island, Hawai'i

This report was commissioned by the U.S. Fish and Wildlife Service (USFWS). The purpose was to develop a monitoring program for Kaua`i forest birds in the USFWS Strategic Habitat Conservation and adaptive management frameworks. Monitoring within those frameworks is a tool to assess resource responses to management and conservation actions, and through an iterative learning process improve our understanding of species recovery, effective management, and knowledge gaps. This report provides only the monitoring component of both frameworks, and we apply the monitoring program to the East Alaka`i Protective Fence Project. The East Alaka`i Protective Fence Project is a joint project by the USFWS, State of Hawai`i Division of Forest and Wildlife, Kaua`i Watershed Alliance, and The Nature Conservancy to restore and preserve an 809 ha area of native forest bird habitat through fencing, and ungulate and weed control. The primary purpose of the project is to restore and preserve the habitat that will in turn support abundant and resilient bird populations. This report contains: A monitoring program specifically developed to track bird distribution, density and demography, and habitat for the East Alaka`i Protective Fence Project; A review of the Kaua`i forest bird surveys; A description of the current status and trends of Kaua`i forest birds; An assessment and evaluation of the current surveys; A monitoring program developed to sample bird distribution, density and demography, and habitat at three general levels of spatial scale. Without the management components described in the East Alaka`i Protective Fence Project and the Revised Recovery Plan for Hawaiian Forest Birds (USFWS 2006) the bird monitoring recommended in this report is little better than surveillance (i.e., monitoring without a link to management). If, however, the proposed management actions are implemented in conjunction with the recommended bird monitoring, then this monitoring program will identify population changes in a timely manner and facilitate identification of the proximate causes of population changes.

Hawaii↗
USGS2000

Monitoring hydrilla using two RAPD procedures and the nonindigenous aquatic species database

Hydrilla (Hydrilla verticillata (L.f.) Royle), an invasive aquatic weed, continues to spread to new regions in the United States. Two biotypes, one a female dioecious and the other monoecious have been identified. Management of the spread of hydrilla requires understanding the mechanisms of introduction and transport, an ability to map and make available information on distribution, and tools to distinguish the known U.S. biotypes as well as potential new introductions. Review of the literature and discussions with aquatic scientists and resource managers point to the aquarium and water garden plant trades as the primary past mechanism for the regional dispersal of hydrilla while local dispersal is primarily carried out by other mechanisms such as boat traffic, intentional introductions, and waterfowl. The Nonindigenous Aquatic Species (NAS) database is presented as a tool for assembling, geo-referencing, and making available information on the distribution of hydrilla. A map of the current range of dioecious and monoecious hydrilla by drainage is presented. Four hydrilla samples, taken from three discrete, non-contiguous regions (Pennsylvania, Connecticut, and Washington State) were examined using two RAPD assays. The first, generated using primer Operon G17, and capable of distinguishing the dioecious and monoecious U.S. biotypes, indicated all four samples were of the monoecious biotype. Results of the second assay using the Stoffel fragment and 5 primers, produced 111 markers, indicated that these samples do not represent new foreign introductions. The differences in the monoecious and dioecious growth habits and management are discussed.

Connecticut, Pennsylvania, Washington↗