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USGS2022

Landscape change, fire and erosion

New Mexico has a dynamic landscape, which will become even more so in response to climate change over the next 50 years, in part because of increasing incidence of wildfire. As the climate changes to warmer conditions, less rainfall will infiltrate into aquifers, leading to increased overland runoff. Landform processes can be complex, but in general, the predicted changes in climate and precipitation will lead to increased flooding, increased upland erosion caused by runoff, and increased downstream sediment deposition. Canyons and mesas, small basins or valleys filled with sediment will be particularly affected. Rapid rearrangement of sediments by water is disruptive and potentially hazardous to ecosystems and societies. Dramatic examples of accelerated erosion following the Whitewater-Baldy, Las Conchas and other wildfires here in New Mexico illustrate the types of hazards created when forested landscapes are severely burned. Post-wildfire erosion is typically initiated by intense rainfall events. Given that both the number of wildfires, and rainfall intensities are likely to increase as the climate warms, New Mexico can expect to see increases in widespread erosion and sedimentation across and downstream from upland forested areas in the state. The large volume of sediment predicted to be on the move will be of concern for many reasons including filling reservoirs, choking channels, blocking or destroying infrastructure and positive feedback loops that lead to further reductions in slope stability.

New Mexico↗

USGS2021

Global application of an unoccupied aerial vehicle photogrammetry protocol for predicting aboveground biomass in non-forest ecosystems

Non-forest ecosystems, dominated by shrubs, grasses and herbaceous plants, provide ecosystem services including carbon sequestration and forage for grazing, and are highly sensitive to climatic changes. Yet these ecosystems are poorly represented in remotely sensed biomass products and are undersampled by in situ monitoring. Current global change threats emphasize the need for new tools to capture biomass change in non-forest ecosystems at appropriate scales. Here we developed and deployed a new protocol for photogrammetric height using unoccupied aerial vehicle (UAV) images to test its capability for delivering standardized measurements of biomass across a globally distributed field experiment. We assessed whether canopy height inferred from UAV photogrammetry allows the prediction of aboveground biomass (AGB) across low-stature plant species by conducting 38 photogrammetric surveys over 741 harvested plots to sample 50 species. We found mean canopy height was strongly predictive of AGB across species, with a median adjusted R 2 of 0.87 (ranging from 0.46 to 0.99) and median prediction error from leave-one-out cross-validation of 3.9%. Biomass per-unit-of-height was similar within but different among, plant functional types. We found that photogrammetric reconstructions of canopy height were sensitive to wind speed but not sun elevation during surveys. We demonstrated that our photogrammetric approach produced generalizable measurements across growth forms and environmental settings and yielded accuracies as good as those obtained from in situ approaches. We demonstrate that using a standardized approach for UAV photogrammetry can deliver accurate AGB estimates across a wide range of dynamic and heterogeneous ecosystems. Many academic and land management institutions have the technical capacity to deploy these approaches over extents of 1–10 ha −1 . Photogrammetric approaches could provide much-needed information required to calibrate and validate the vegetation models and satellite-derived biomass products that are essential to understand vulnerable and understudied non-forested ecosystems around the globe.

Remote Sensing in Ecology and Conservation↗

USGS1997

Clonal expansion and seedling recruitment of Oregon grape (Berberis nervosa) in Douglas-fir (Pseudotsuga menziesii) forests: Comparisons with salal (Gaultheria shallon)

Seedling regeneration and morphology of Oregon grape ( Berberis nervosa Pursh) and salal ( Gaultheria shallon Pursh) were studied in thinned and unthinned Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) stands in the central Coast Range, Oregon. Above- and below-ground growth of both species were significantly and negatively correlated with stand density. Oregon grape appears to have less potential for vegetative spread than does salal. It produced two to three times fewer rhizome extensions, and rhizome extensions were only half as long as those of salal. Oregon grape seedlings were common in areas of moss ground cover among patches of the two species. Salal seedlings were restricted to decaying logs. Seedling densities of Oregon grape in thinned stands were more than six times those in unthinned stands. For Oregon grape, understory establishment is accomplished by seedling establishment and recruitment of new genets. In contrast, salal maintains itself in forest understories primarily through vegetative growth, since its seedling establishment is restricted mainly to decayed wood. Continual recruitment of new aerial stems or ramets enables Oregon grape to maintain a dense cover once it is established in the understory.

Canadian Journal of Forest Research↗

USGS2025

Status and trends of forest bird populations at Hakalau Forest National Wildlife Refuge, 1987–2024

Since 1985, the Hakalau Forest Unit of the Big Island National Wildlife Refuge Complex (hereafter, Hakalau) has protected the largest endemic forest bird diversity in the State of Hawaii. This includes three endangered and one threatened species and their habitats. Hakalau’s vast area (155 km2), mostly high elevation (>1500 m) montane forest, provides refuge from avian malaria (Plasmodium relictum) vectored by introduced southern house mosquitoes (Culex quinquefasciatus). However, increases in the seasonal temperatures optimal for disease carrying mosquitoes associated with climate change have coincided with recent downward trends of native species in the closed forest area of the refuge (1450–1750 m), where disease is most likely to occur. Therefore, to inform refuge management with the most updated information on these populations and their trends, we analyzed forest bird survey data collected using point transect distance sampling with new survey data from 2021–2024. We stratified our analysis across management units, including the open forest and pasture since 1987, and the closed forest since 1999, and across four elevation ranges (<1500, 1500–1700, 1700–1900, and >1900 m) since 1999. We used distance sampling to estimate species- and strata-specific abundances and applied log-linear regression to detect trends across the timeseries. We found a continuation of previous trends, wherein most native forest birds declined in the closed forest strata (mostly below 1700 m) and increased in the highest elevation and pasture strata. Patterns were highly species-specific for the three lower elevations and open forest strata. ‘Apapane (Himatione sanguinea) and warbling white-eye (Zosterops japonicus), the most abundant native and introduced bird species, respectively, increased in nearly all strata. ‘I‘iwi (Drepanis coccinea) and Hawai‘i ‘amakihi (Chlorodrepanis virens virens), also common, decreased in closed forest, were stable in open forest, and increased in pasture. Both species were generally stable or increasing across all elevation bands, except Hawaiʻi ʻamakihi decreased in the below 1500 m and the 1500–1700 m elevation bands. All three of the federally endangered forest bird species declined in closed forest. Hawai‘i ‘ākepa (Loxops coccineus) also declined in the open forest and 1700–1900 m band and was the only species to decline overall. ‘Akiapōlā‘au (Hemignathus wilsoni) declined in closed forest but increased overall. ‘Alawī (Loxops mana, also known as Hawai‘i creeper) also decreased in the closed forest, but was stable to increasing in most strata and remained stable overall. Hawaiʻi ʻelepaio (Chasiempis sandwichensis) declined in closed forest, was stable in open forest and most elevation strata, and increased in pasture. ʻŌmaʻo (Myadestes obscurus) was stable in open and closed forest and at middle elevations and increased in the pasture. Introduced red-billedleiothrix (Leiothrix lutea) declined in closed forest, was stable in the open forest and at most elevations, and increased in the pasture. Coinciding with these changes, seasonal conditions for vector occurrence have continued to lengthen in the lower elevation strata through 2024, while Hakalau’s outplanting efforts continued to increase forest cover in the pasture, suggesting that disease-free habitat may have decreased in the closed forest and increased in the pasture. The declines in the closed forest and mixture of trends in the open forest and middle elevations bands suggest emigration into the higher elevation strata from lower elevation strata, and that possible threats have suppressed forest birds even at elevations >1500 m.

Hawaii↗

USGS2002

Parasitism at the landscape scale: Cowbirds prefer forests

Landscape-scale examination of parasitism patterns of Brown-headed Cowbirds ( Molothrus ater ) revealed heterogeneous parasitism rates across the mosaic of a forest and associated old-field communities. In a two year study in Dutchess County, New York, we found a significantly higher parasitism rate in the forest-interior community ( n = 301 nests; 17 species) than on the species in the adjacent and nearby old field and edge ( n = 328 nests; 15 species; 32.3% versus 6.5%; p < 0.0001). Cowbirds invaded a mature 1300-ha forest stand even when their traditional host species were available in adjacent old-field and edge habitats. The forest and old-field study areas were located in a 38,000-ha township with 55% forest cover and contained numerous agriculture, dairy, and horse farms that provided favorable habitat for cowbirds. Within-forest examination of parasitism patterns revealed four aspects of cowbird parasitism that contrasted with patterns described in other regions: (1) parasitism was concentrated significantly more often on ground- and low-nesting (nests ≤ 1 m) forest species than on medium- and high-nesting species (nests> 1 m; 35.01% versus 29.93%; p = 0.0393); (2) parasitism was not significantly greater on Neotropical migrant species than on short-distance migrants and residents; (3) the parasitism rate was not higher in nests close to edges; and (4) the parasitism level was low on certain forest species (such as Wood Thrush) that have experienced high parasitism levels in the Midwest. From a management perspective these data suggest that cowbirds exhibit regional differences in host and habitat use; the target host community of a particular cowbird population is unpredictable at the landscape scale; and a landscape scale should be used in designing cowbird studies to accurately assess local population dynamics.

New York↗

USGS1996

Soil and soil solution chemistry under red spruce stands across the northeastern united states

Red spruce ecosystems in the northeastern United States are of interest because this species is undergoing regional decline. Their underlying soils have been examined closely at only a few sites, and information available on red spruce soils throughout this region is limited.This study was conducted to examine soil and soil solution chemistry at red spruce sites in the northeastern US that encompass the range of soil conditions in which red spruce grow. Soils and soil solutions from Oa and B horizons were obtained over a 2-year period from 12 undisturbed red spruce forests (elevations of 80-975 m) in New York, Vermont, New Hampshire, and Maine. All sites had extremely acid Spodosols (Oa soil pH range 2.56 to 3.11 in 0.01 M CaCl2), with generally low concentrations of base cations and high concentrations of Al on soil exchange sites. There was considerable range in exchange chemistry across the sites, however, with exchangeable Ca in Oa horizons ranging from 2.1 to 21.6 cmolckg-1 and exchangeable Al from 3.6 to 18.3 cmolckg-1. Solution chemistry had high concentrations of DOC in the Oa horizons (1160-15200 ??mol L-1), with higher concentrations in the fall than in the spring, which was probably a reflection of fresh litter inputs. Despite high concentrations of DOC in all solutions, inorganic Al was found in some Oa solutions at concentrations as high as 26 ??mol L-1. Ratios of Ca2+ to inorganic Al concentraturns were less than 1.0 in the Oa horizon of one site, and were well below 1.0 in B horizons of all sites. That soil chemistry was related to soil solution chemistry was demonstrated by solution Al concentrations in the forest floor having significant relationships with pyrophosphate extractable Al, although it was not related in the B horizon. Soil exchangeable Ca/Al ratios in the Oa horizon explained 75% of the variation in solution Ca2+/inorganic Al ratios when mean values were used for each site. Our studies have expanded the range of soil chemical conditions measured for red spruce soils. By characterizing the regional variability, these results will enable site intensive process studies to be better applied to regional problems such as spruce decline.

Soil Science↗

USGS1998

Retention of NO3/- in an upland stream environment: A mass balance approach

Models of the effects of atmospheric N deposition in forested watersheds have not adequately accounted for the effects of aquatic and near-stream processes on the concentrations and loads of NO3/- in surface waters. This study compared the relative effects of aquatic and near-stream processes with those from the terrestrial ecosystem on the retention and transport of NO3/- in two contrasting stream reaches of the Neversink River, a forested watershed in the Catskill Mountains of New York that receives among the highest load of atmospheric N deposition in the northeastern United States. Stream water samples were collected every two hours and ground-water and tributary samples were collected daily at base flow conditions during four 48-hour periods from April to October 1992, and NO3/- mass balances were calculated for each site. Results indicated diurnal variations in stream NO3/- concentrations in both reaches during all four sampling periods; this is consistent with uptake of NO3/- by photoautotrophs during daylight hours. Mass-balance results revealed significant stream reach losses of NO3/- at both sites during all sampling periods. The diurnal variations in NO3/- concentrations and the retention of NO3/- relative to terrestrial contributions to the stream reaches were greater downstream than upstream because physical factors such as the head gradients of inflowing ground water and the organic matter content of sediment are more favorable to uptake and denitrification downstream. The mass retention of NO3/- increased as the mean 48-hr stream discharge increased at each site, indicating that the responsible processes are dependent on NO3/- supply. Low stream temperatures during the April sampling period, however, probably reduced the rate of retention processes, resulting in smaller losses of NO3/- than predicted from stream discharge alone. Water samples collected from the stream, the hyporheic zone, and the alluvial ground water at sites in both reaches indicated that the net effect of hyporheic processes on downstream NO3/- transport ranged from conservative mixing to complete removal by denitrification. The relative effects of biological uptake and denitrification as retention mechanisms could not be quantified, but the results indicate that both processes are significant. These results generally confirm that aquatic and near-stream processes cause significant losses of NO3/- in the Neversink River, and that the losses by these processes at downstream locations can exceed the NO3/- contributions to the stream from the terrestrial environment during summer and fall base-flow conditions. Failure to consider these aquatic and near-stream processes in models of watershed response to atmospheric N deposition could result in underestimates of the amount of NO3/- leaching from forested ecosystems and to an inability to unequivocally relate geographic differences in NO3/- concentrations of stream waters to corresponding differences in terrestrial processes.

Biogeochemistry↗

USGS2001

Controls of stream chemistry and fish populations in the Neversink watershed, Catskill Mountains, New York

The Neversink Watershed Study was initiated in 1991 to develop an understanding of the key natural processes that control water quality within the forested, 166 km 2 (64 mi 2 ), Neversink River watershed; part of the New York City drinking water supply system, in the Catskill Mountain region of New York. The study entailed (1) hydrological investigations of water movement from the atmosphere to streams, (2) biogeochemical investigations of nitrogen and calcium, important nutrients in forest and aquatic ecosystems whose availability has been altered by acidic deposition, (3) an investigation of elevational patterns in atmospheric deposition, and (4) fisheries investigations to determine the relative importance of physical habitat and acidic deposition in controlling the abundance and diversity of fish species in the watershed. This report summarizes the results of these investigations, which have also been presented, in detail, in peer-reviewed technical articles and reports that are cited throughout the text.

New York↗

USGS2008

Temporal change in fragmentation of continental US forests

Changes in forest ecosystem function and condition arise from changes in forest fragmentation. Previous studies estimated forest fragmentation for the continental United States (US). In this study, new temporal land-cover data from the National Land Cover Database (NLCD) were used to estimate changes in forest fragmentation at multiple scales for the continental US. Early and late dates for the land-cover change data were ca. 1992 and ca. 2001. Forest density was used as a multi-scale index of fragmentation by measuring the proportion of forest in neighborhoods ranging in size from 2.25 to 5314.41 ha. The multi-scale forest density maps were classified using thresholds of 40% (patch), 60% (dominant), and 90% (interior) to analyze temporal change of fragmentation. The loss of dominant and interior forest showed distinct scale effects, whereas loss of patch forest was much less scale-dependent. Dominant forest loss doubled from the smallest to the largest spatial scale, while interior forest loss increased by approximately 80% from the smallest to the second largest spatial scale, then decreased somewhat. At the largest spatial scale, losses of dominant and interior forest were 5 and 10%, respectively, of their ca. 1992 amounts. In contrast, patch forest loss increased by only 25% from the smallest to largest spatial scale. These results indicate that continental US forests were sensitive to forest loss because of their already fragmented state. Forest loss would have had to occur in an unlikely spatial pattern in order to avoid the proportionately greater impact on dominant and interior forest at larger spatial scales.

Landscape Ecology↗

USGS2017

Climate change and collapsing thermal niches of Mexican endemic reptiles

Recent climate change should result in expansion of species to northern or high elevation range margins, and contraction at southern and low elevation margins due to extinction. Climate models predict dramatic extinctions and distributional shifts in the next century, but there are few ground-truths of these dire forecasts leading to uncertainty in predicting extinctions due to climate change. Previously, we reported on recent extinctions of Mexican Sceloporus lizards by comparing recent surveys to historical distributional records for 48 species at 200 sites. We also ground-truthed extinctions on five continents across 8 lizard families by comparing observed and predicted extinctions from an eco-physiological species distribution model and obtained a high R 2 of 0.72 (1, 2). Here, we derive more detailed predictions for 15 terrestrial reptile families and 142 species for the Mexican and California Biogeographic provinces using all known museum occurrence records, and detailed measures on eco-physiology. We adopt the eco-physiological model of extinction developed earlier but use a species-specific model. We predict massive and rapid extinctions of 22% of the reptile populations in Mexico within the next 50 years. We also predict that 3 of 15 reptile families, all three endemic to the Mexican and Californian biogeographic provinces, will go extinct by 2070, the hallmark of the beginnings of a mass extinction event. However, extinctions may be attenuated by forest cover and by presence of montane environments in contemporary ranges. We describe impacts of altitude on three species (Gopherus morafkai, G. evgoodei, and Gambelia sila) to illustrate regional management strategies (AZ-Mexico, Sinoloa, CA) for reserves in tandem with global strategies of CO2 limits that might limit climate impacts. By carefully selecting new montane preserves adjacent to desert and tropical forest habitats, and by implementing global controls on atmospheric CO2 emissions, extinctions may be reduced to less than 11% of species and only a single reptile family.

Report↗

USGS2007

Restoring coastal wetlands that were ditched for mosquito control: a preliminary assessment of hydro-leveling as a restoration technique

The wetlands surrounding Tampa Bay, Florida were extensively ditched for mosquito control in the 1950s. Spoil from ditch construction was placed adjacent to the wetlands ditches creating mound-like features (spoil-mounds). These mounds represent a loss of 14% of the wetland area in Tampa Bay. Spoil mounds interfere with tidal flow and are locations for non-native plants to colonize (e.g., Schinus terebinthifolius ). Removal of the spoil mounds to eliminate exotic plants, restore native vegetation, and re-establish natural hydrology is a restoration priority for environmental managers. Hydro-leveling, a new technique, was tested in a mangrove forest restoration project in 2004. Hydro-leveling uses a high pressure stream of water to wash sediment from the spoil mound into the adjacent wetland and ditch. To assess the effectiveness of this technique, we conducted vegetation surveys in areas that were hydro-leveled and in non-hydro-leveled areas 3 years post-project. Adult Schinus were reduced but not eliminated from hydro-leveled mounds. Schinus seedlings however were absent from hydro-leveled sites. Colonization by native species was sparse. Mangrove seedlings were essentially absent (≈2 m −2 ) from the centers of hydro-leveled mounds and were in low density on their edges (17 m −2 ) in comparison to surrounding mangrove forests (105 m −2 ). Hydro-leveling resulted in mortality of mangroves adjacent to the mounds being leveled. This was probably caused by burial of pneumatophores during the hydro-leveling process. For hydro-leveling to be a useful and successful restoration technique several requirements must be met. Spoil mounds must be lowered to the level of the surrounding wetlands. Spoil must be distributed further into the adjacent wetland to prevent burial of nearby native vegetation. Finally, native species may need to be planted on hydro-leveled areas to speed up the re-vegetation process.

Journal of Coastal Conservation↗

USGS2008

Faunal impact on vegetation structure and ecosystem function in mangrove forests: A review

The last 20 years witnessed a real paradigm shift concerning the impact of biotic factors on ecosystem functions as well as on vegetation structure of mangrove forests. Before this small scientific revolution took place, structural aspects of mangrove forests were viewed to be the result of abiotic processes acting from the bottom-up, while, at ecosystem level, the outwelling hypothesis stated that mangroves primary production was removed via tidal action and carried to adjacent nearshore ecosystems where it fuelled detrital based food-webs. The sesarmid crabs were the first macrofaunal taxon to be considered a main actor in mangrove structuring processes, thanks to a number of studies carried out in the Indo-Pacific forests in the late 1970s and early 1980s. Following these classical papers, a number of studies on Sesarmidae feeding and burrowing ecology were carried out, which leave no doubts about the great importance of these herbivorous crabs in structuring and functioning Old world ecosystems. Although Sesarmidae are still considered very important in shaping mangrove structure and functioning, recent literature emphasizes the significance of other invertebrates. The Ocypodidae have now been shown to have the same role as Sesarmidae in terms of retention of forest products and organic matter processing in New world mangroves. In both New and Old world mangroves, crabs process large amounts of algal primary production, contribute consistently to retention of mangrove production and as ecosystem engineers, change particle size distribution and enhance soil aeration. Our understanding of the strong impact of gastropods, by means of high intake rates of mangrove products and differential consumption of propagules, has changed only recently. The role of insects must also be stressed. It is now clear that older techniques used to assess herbivory rates by insects strongly underestimate their impact, both in case of leaf eating and wood boring species and that herbivorous insects can potentially play a strong role in many aspects of mangrove ecology. Moreover, researchers only recently realized that ant–plant interactions may form an important contribution to our understanding of insect–plant dynamics in these habitats. Ants seem to be able to relieve mangroves from important herbivores such as many insects and sesarmid crabs. It thus seems likely that ants have positive effects on mangrove performance.

Aquatic Botany↗

USGS2024

Recent, widespread nitrate decreases may be linked to persistent dissolved organic carbon increases in headwater streams recovering from past acidic deposition

Long-term monitoring of water quality responses to natural and anthropogenic perturbation of watersheds informs policies for managing natural resources. Dissolved organic carbon (DOC) and nitrate (NO 3 − ) in streams draining forested landscapes provide valuable information on ecosystem function due to their biogeochemical reactivity and solubility in water. Here we evaluate a 20-year record (2001−2021) of biweekly stream-water samples ( n > 3000) and continuous discharge in three forested catchments in the Adirondack region of New York to investigate and interpret long-term trends in DOC and NO 3 − concentrations. Results from the intensively monitored catchments were compared with data from synoptic surveys of streams throughout the Adirondack region. A weighted regressions on time, discharge, and season (WRTDS) model, used to estimate daily flow-normalized concentrations, determined that DOC increased by ~30 to 50 % while NO 3 − decreased by ~50 to 70 % over the study period. The large amount of data from catchments with different soil properties permitted us to assess the relative effects of hydrology, season, and land cover factors on temporal trends in DOC and NO 3 − concentrations. We found weak evidence of climatic forcing of long-term increases in DOC, and instead contend that declining ionic strength in precipitation linked to declining anthropogenic acid deposition is driving DOC trends in stream waters. Nitrate concentrations were more variable but clearly decreased in recent years possibly related to declining N deposition. The recent increase in DOC:NO 3 − in all catchments indicates a major shift in stream stoichiometry that reflects changes in ecosystem functioning that may have important biogeochemical implications for terrestrial as well as aquatic ecosystems.

Science of the Total Environment↗

USGS2006

Streams in Catskill Mountains still susceptible to acid rain

Precipitation in North America has become less acidic over the past 2 decades because of reduced power plant emissions and compliance with the Clean Air Act Amendments [ Sirois , 19937rsqb;. The 1990 Clean Air Act Amendments were developed to reduce the acidity of sensitive surface waters, which are primarily in upland forested environments, where acidified waters and associated high aluminum concentrations are toxic to many species of aquatic flora and fauna [ Schindler et al. , 1989]. Our studies show that in spite of less acidic precipitation, the buffering capacity of streams in upland forests of the Catskill Mountains in southeastern New York has not increased in recent years. These data suggest that long-term leaching by acid rain has lowered exchangeable calcium ion concentrations in the soil in upland areas, where the underlying, slow-weathering bedrock provides an inadequate supply of cations to neutralize acidity.

New York↗

USGS2006

Old-growth forests can accumulate carbon in soils

Old-growth forests have traditionally been considered negligible as carbon sinks because carbon uptake has been thought to be balanced by respiration. We show that the top 20-centimeter soil layer in preserved old-growth forests in southern China accumulated atmospheric carbon at an unexpectedly high average rate of 0.61 megagrams of carbon hectare-1 year-1 from 1979 to 2003. This study suggests that the carbon cycle processes in the belowground system of these forests are changing in response to the changing environment. The result directly challenges the prevailing belief in ecosystem ecology regarding carbon budget in old-growth forests and supports the establishment of a new, nonequilibrium conceptual framework to study soil carbon dynamics.

Science↗

USGS2011

The 1996-2009 borehole dilatometer installations, operation, and maintenance at sites in Long Valley Caldera, CA

High seismicity levels with accelerating uplift (under the resurgent dome) in Long Valley caldera in the eastern Sierra Nevada from 1989 to 1997, triggered upgrades to dilational strainmeters and other instrumentation installed in the early 1980's following a series of magnitude 6 earthquakes. This included two additional high-resolution borehole strainmeters and replacement of the failed strainmeter at Devil's Postpile. The purpose of the borehole-monitoring network is to monitor crustal deformation and other geophysical parameters associated with volcanic intrusions and earthquakes in the Long Valley Caldera. Additional instrumentation was added at these sites to improve the capability of providing continuous monitoring of the magma source under the resurgent dome. Sites were selected in regions of hard crystalline rock, where the expected signals from magmatic activity were calculated to be a maximum and the probability of an earthquake of magnitude 4 or greater is large. For the most part, the dilatometers were installed near existing arrays of surface tiltmeters, seismometers, level line, and GPS arrays. At each site, attempts are made to separate tectonic and volcanic signals from known noise sources in each instrument type. Each of these sites was planned to be a multi-parameter monitoring site, which included measurements of 3-component seismic velocity and acceleration, borehole strain, tilt, pore pressure and magnetic field. Using seismicity, geophysical knowledge, geologic and topographic maps, and geologists recommendations, lists of preliminary sites were chosen. Additional requirements were access, and telemetry constraints. When the final site choice was made, a permit was obtained from the U.S. Forest Service. Following this selection process, two new borehole sites were installed on the north and south side of the Long Valley Caldera in June of 1999. One site was located near Big Spring Campground to the east of Crestview. The second site was located at the Motocross Track (near Old Mammoth) in the South Moat. This report describes the methods used to install these strainmeters and various other types of borehole instruments at these sites together with the site at Devil's Postpile and telemeter the data obtained to the USGS base in Menlo Park, Calif.

California↗

USGS2011

CRMS vegetation analytical team framework: Methods for collection, development, and use of vegetation response variables

This document identifies the main objectives of the Coastwide Reference Monitoring System (CRMS) vegetation analytical team, which are to provide (1) collection and development methods for vegetation response variables and (2) the ways in which these response variables will be used to evaluate restoration project effectiveness. The vegetation parameters (that is, response variables) collected in CRMS and other coastal restoration projects funded under the Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA) are identified, and the field collection methods for these parameters are summarized. Existing knowledge on community and plant responses to changes in environmental drivers (for example, flooding and salinity) from published literature and from the CRMS and CWPPRA monitoring dataset are used to develop a suite of indices to assess wetland condition in coastal Louisiana. Two indices, the floristic quality index (FQI) and a productivity index, are described for herbaceous and forested vegetation. The FQI for herbaceous vegetation is tested with a long-term dataset from a CWPPRA marsh creation project. Example graphics for this index are provided and discussed. The other indices, an FQI for forest vegetation (that is, trees and shrubs) and productivity indices for herbaceous and forest vegetation, are proposed but not tested. New response variables may be added or current response variables removed as data become available and as our understanding of restoration success indicators develops. Once indices are fully developed, each will be used by the vegetation analytical team to assess and evaluate CRMS/CWPPRA project and program effectiveness. The vegetation analytical teams plan to summarize their results in the form of written reports and/or graphics and present these items to CRMS Federal and State sponsors, restoration project managers, landowners, and other data users for their input.

Open-File Report↗

USGS2019

Simulating land cover change impacts on groundwater recharge under selected climate projections, Maui, Hawaiʻi

This project developed an integrated land cover/hydrological modeling framework using remote sensing and geographic information systems (GIS) data, stakeholder input, climate information and projections, and empirical data to estimate future groundwater recharge on the Island of Maui, Hawaiʻi, USA. End-of-century mean annual groundwater recharge was estimated under four future land cover scenarios: Future 1 (conservation-focused), Future 2 (status-quo), Future 3 (development-focused), and Future 4 (balanced conservation and development), and two downscaled climate projections: a coupled model intercomparison project (CMIP) phase 5 (CMIP5) representative concentration pathway (RCP) 8.5 “dry climate” future and a CMIP3 A1B “wet climate” future. Results were compared to recharge estimated using the 2017 baseline land cover to understand how changing land management and climate could influence groundwater recharge. Estimated recharge increased island-wide under all future land cover and climate combinations and was dominated by specific land cover transitions. For the dry future climate, recharge for land cover Futures 1 to 4 increased by 12%, 0.7%, 0.01%, and 11% relative to 2017 land cover conditions, respectively. Corresponding increases under the wet future climate were 10%, 0.9%, 0.6%, and 9.3%. Conversion from fallow/grassland to diversified agriculture increased irrigation, and therefore recharge. Above the cloud zone (610 m), conversion from grassland to native or alien forest led to increased fog interception, which increased recharge. The greatest changes to recharge occurred in Futures 1 and 4 in areas where irrigation increased, and where forest expanded within the cloud zone. Furthermore, new future urban expansion is currently slated for coastal areas that are already water-stressed and had low recharge projections. This study demonstrated that a spatially-explicit scenario planning process and modeling framework can communicate the possible consequences and tradeoffs of land cover change under a changing climate, and the outputs from this study serve as relevant tools for landscape-level management and interventions.

Hawaii↗