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2015

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Articles 571 - 600 of 1152

Full-Text Articles in Earth Sciences

Model Of Residence Time And Analysis Of Nitrogen Removal For Two Constructed Wetlands At The Franklin Demonstration Farm In Lexington, Illinois, Emma Singh Baghel Apr 2015

Model Of Residence Time And Analysis Of Nitrogen Removal For Two Constructed Wetlands At The Franklin Demonstration Farm In Lexington, Illinois, Emma Singh Baghel

Theses and Dissertations

Pollution from nonpoint agricultural runoff has become a major problem facing our streams and rivers today. Not only are fish and aquatic life affected, but so is the quality of our drinking and recreational water resources. Studies have shown that wetlands have proven to be the most cost-effective and low maintenance method of removing nonpoint or diffused contaminate inputs. The biological processes and removal of nutrients in wetlands depend on the total surface area available for microbial activity in the soil and a certain period of water retention time. Since chemical processes take time, the measure of residence time is …


Effects Of Physical Characteristics Of Urban Storm Sewersheds On Water Quality In Bloomington, Il, Alicia Terese O'Hare Apr 2015

Effects Of Physical Characteristics Of Urban Storm Sewersheds On Water Quality In Bloomington, Il, Alicia Terese O'Hare

Theses and Dissertations

Increasing urbanization has consequences for surface water quality. Stormwater is a large component of urban water degradation that is poorly understood. Precipitation is quickly transported via underground pipes, from the land to the stream without following water's natural flow path. Studies have correlated detention ponds with improved water quality and impervious surface cover with degraded water quality. However, other physical characteristics within a storm sewer shed including the presence of sump pumps, area and pipe miles may also affect the stormwater quality. We chose 18 storm sewer systems in Bloomington, IL. We measured pH, temperature, conductivity, dissolved oxygen, chloride, nitrate, …


Linking Hematite (Uth)/He Dating With The Microtextural Record Of Seismicity In The Wasatch Fault Damagezone, Utah, Usa, Alexis K. Ault, Peter W. Reiners, James P. Evans, Stuart N. Thomson Apr 2015

Linking Hematite (Uth)/He Dating With The Microtextural Record Of Seismicity In The Wasatch Fault Damagezone, Utah, Usa, Alexis K. Ault, Peter W. Reiners, James P. Evans, Stuart N. Thomson

Geosciences Faculty Publications

Techniques directly dating fault slip are few, limiting the ability to interpret the rock record of seismicity. Hematite is commonly found in fault zones, amenable to (U-Th)/He dating, and slip surface hematite may be reset by shear heating events and/or recrystallization. Glossy hematite-coated fault surfaces in the Wasatch fault footwall damage zone, Utah (USA), exhibit evidence of hematite cataclasis and preserve Pliocene hematite (U-Th)/He dates. Apatite (U-Th)/He and fission track data from the host gneiss indicate footwall unroofing through ∼2 km by ca. 4.5 Ma. Internally reproducible but disparate hematite (U-Th)/He dates 4.5 Ma and younger from isolated locations on …


Quantifying Meltwater Refreezing Along A Transect Of Sites On The Greenland Ice Sheet, C. Cox, N. Humphrey, Joel T. Harper Apr 2015

Quantifying Meltwater Refreezing Along A Transect Of Sites On The Greenland Ice Sheet, C. Cox, N. Humphrey, Joel T. Harper

Geosciences Faculty Publications

On the Greenland ice sheet, a significant quantity of surface meltwater refreezes within the firn, creating uncertainty in surface mass balance estimates. This refreezing has the potential to buffer seasonal runoff to future increases in melting, but direct measurement of the process remains difficult. We present a method for quantifying refreezing at point locations using in situ firn temperature observations. A time series of sub-hourly firn temperature profiles were collected over the course of two melt seasons from 2007 to 2009 along a transect of 11 sites in the accumulation zone of Greenland. Seasonal changes in temperature profiles combined with …


Analysis Of Spatial Variability Of Near-Surface Soil Moisture To Increase Rainfall-Runoff Modelling Accuracy In Sw Hungary, P. Hegedüs, S. Czigány, E. Pirkhoffer, L. Balatonyi, Robert Hickey Apr 2015

Analysis Of Spatial Variability Of Near-Surface Soil Moisture To Increase Rainfall-Runoff Modelling Accuracy In Sw Hungary, P. Hegedüs, S. Czigány, E. Pirkhoffer, L. Balatonyi, Robert Hickey

All Faculty Scholarship for the College of the Sciences

Between September 5, 2008 and September 5, 2009, near-surface soil moisture time series were collected in the northern part of a 1.7 km2 watershed in SWHungary at 14 monitoring locations using a portable TDR-300 soil moisture sensor. The objectives of this study are to increase the accuracy of soil moisture measurement at watershed scale, to improve flood forecasting accuracy, and to optimize soil moisture sensor density.

According to our results, in 10 of 13 cases, a strong correlation exists between the measured soil moisture data of Station 5 and all other monitoring stations; Station 5 is considered representative for the …


Longitudinal Profile And Sediment Mobility As Geomorphic Tools To Interpret The History Of A Fluviokarst Stream System, John Woodside, Eric Wade Peterson, Toby Dogwiler Apr 2015

Longitudinal Profile And Sediment Mobility As Geomorphic Tools To Interpret The History Of A Fluviokarst Stream System, John Woodside, Eric Wade Peterson, Toby Dogwiler

International Journal of Speleology

The complex drainage systems within karst settings can result in atypical longitudinal profiles. Features, such as cave entrances, can be expressed as anomalous ‘bumps’ in the longitudinal profile of a stream if downcutting has continued upstream of the area in which the water is pirated to the subsurface. Horn Hollow, a fluviokarst valley located in Carter Caves State Park Resort in northeastern Kentucky, was examined for these types of features. The objectives of this study were to determine if sediment mobility can be used as a proxy for anomalous areas along the profile of the valley and if detailed cross-sections …


U.S. Drought Monitor, April 14, 2015, Michael J. Brewer Apr 2015

U.S. Drought Monitor, April 14, 2015, Michael J. Brewer

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for April 14, 2015 (4/14/15) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.


Twentieth Century Dust Lows And The Weakening Of The Westerly Winds Over The Tibetan Plateau, Bjorn Grigholm, P. A. Mayewski, S. Kang, Y. Zhang, U. Morgenstern, M. Schwikowski, Susan D. Kaspari, V. Aizen, E. Aizen, N. Takeuchi, K. A. Maasch, S. Birkel, M. Handley, S. Sneed Apr 2015

Twentieth Century Dust Lows And The Weakening Of The Westerly Winds Over The Tibetan Plateau, Bjorn Grigholm, P. A. Mayewski, S. Kang, Y. Zhang, U. Morgenstern, M. Schwikowski, Susan D. Kaspari, V. Aizen, E. Aizen, N. Takeuchi, K. A. Maasch, S. Birkel, M. Handley, S. Sneed

All Faculty Scholarship for the College of the Sciences

Understanding past atmospheric dust variability is necessary to put modern atmospheric dust into historical context and assess the impacts of dust on the climate. In Asia, meteorological data of atmospheric dust is temporally limited, beginning only in the 1950s. High‐resolution ice cores provide the ideal archive for reconstructing preinstrumental atmospheric dust concentrations. Using a ~500 year (1477–1982 A.D.) annually resolved calcium (Ca) dust proxy from a Tibetan Plateau (TP) ice core, we demonstrate the lowest atmospheric dust concentrations in the past ~500 years during the latter twentieth century. Declines in late nineteenth to twentieth century Ca concentrations significantly correspond with …


Reconstructing Thermal Properties Of Firn At Summit, Greenland, From A Temperature Profile Time Series, Alexandra L. Giese, Robert L. Hawley Apr 2015

Reconstructing Thermal Properties Of Firn At Summit, Greenland, From A Temperature Profile Time Series, Alexandra L. Giese, Robert L. Hawley

Dartmouth Scholarship

We have constrained the value for thermal diffusivity of near-surface snow and firn at Summit Station, Greenland, using a Fourier-type analysis applied to hourly temperature measurements collected from eight thermistors in a closed-off, air-filled borehole between May 2004 and July 2008. An implicit, finite-difference method suggests that a bulk diffusivity of ∼25 ± 3m2 a−1 is the most reasonable for representing macroscale heat transport in the top 30 m of firn and snow. This value represents an average diffusivity and, in a conduction-only model, generates temperature series whose phase shifts with depth most closely match those of the Summit borehole …


Accelerated Glacier Melt On Snow Dome, Mount Olympus, Washington, Usa, Due To Deposition Of Black Carbon And Mineral Dust From Wildfire, Susan D. Kaspari, S. Mckenzie Skiles, Ian Delaney, Daniel Dixon, Thomas H. Painter Apr 2015

Accelerated Glacier Melt On Snow Dome, Mount Olympus, Washington, Usa, Due To Deposition Of Black Carbon And Mineral Dust From Wildfire, Susan D. Kaspari, S. Mckenzie Skiles, Ian Delaney, Daniel Dixon, Thomas H. Painter

All Faculty Scholarship for the College of the Sciences

Assessing the potential for black carbon (BC) and dust deposition to reduce albedo and accelerate glacier melt is of interest in Washington because snow and glacier melt are an important source of water resources, and glaciers are retreating. In August 2012 on Snow Dome, Mount Olympus, Washington, we measured snow surface spectral albedo and collected surface snow samples and a 7 m ice core. The snow and ice samples were analyzed for iron (Fe, used as a dust proxy) via inductively coupled plasma sector field mass spectrometry, total impurity content gravimetrically, BC using a single-particle soot photometer (SP2), and charcoal …


On The Influence Of Ionic Strength On Radium And Strontium Sorption To Sandy Loam Soils, Brian A. Powell, Todd Miller, Daniel I. Kaplan Apr 2015

On The Influence Of Ionic Strength On Radium And Strontium Sorption To Sandy Loam Soils, Brian A. Powell, Todd Miller, Daniel I. Kaplan

Journal of the South Carolina Academy of Science

Models which can estimate environmental transport of radioactive contaminants in natural and engineered systems are required to 1) deploy effective remediation strategies for contaminated sites, 2) design waste repositories for future waste streams, and 3) ensure protection of human and environmental health in all cases. These models require accurate transport parameters in order to correctly predict how these contaminants will move in the subsurface. This work aimed to determine more accurately the distribution coefficients for radium and strontium sorption to Savannah River Site (SRS) soils. Radium and strontium sorption to the soils was found to be highly dependent upon ionic …


Landforms Along The Lower Columbia River And The Influence Of Humans, Charles Matthew Cannon Apr 2015

Landforms Along The Lower Columbia River And The Influence Of Humans, Charles Matthew Cannon

Dissertations and Theses

River systems, such as the Columbia River in the Pacific Northwest, USA have been influenced by human activities, resulting in changes to the physical processes that drive landform evolution. This work describes an inventory of landforms along the Columbia River estuary between the Pacific Ocean and Bonneville Dam in Oregon and Washington. Groupings of landforms are assigned to formative process regimes that are used to assess historical changes to floodplain features. The estuary was historically a complex system of channels with a floodplain dominated by extensive tidal wetlands in the lower reaches and backswamp lakes and wetlands in upper reaches. …


Mid-Holocene Speleothem Climate Proxy Records From Florida And Belize, Anna L. Pollock Apr 2015

Mid-Holocene Speleothem Climate Proxy Records From Florida And Belize, Anna L. Pollock

USF Tampa Graduate Theses and Dissertations

As global temperatures rise due to anthropogenic climate change, water resources, thus economies, are threatened. A geologically recent period of increased temperatures is the mid-Holocene and an investigation of its climate may allow for a better understanding of future precipitation and changes to regional water resources. The regions of interest are tropical Northern Central America and subtropical North America with Belize and Florida representing each climate zone. By reconstructing mid-Holocene climate in Florida and Belize, I hope to provide a better understanding of how increased temperatures and a reduced latitudinal temperature gradient impacts both precipitation patterns and variability. Today, drivers …


Tempestites Of The Entrada Sandstone: Mapping And Reservoir Characterization, Jeffery Valenza, Dr. Tom Morris Apr 2015

Tempestites Of The Entrada Sandstone: Mapping And Reservoir Characterization, Jeffery Valenza, Dr. Tom Morris

Journal of Undergraduate Research

Tempestites are sedimentary deposits traditionally thought to be formed by high-energy storm events. Typically, water depth for tempestites has been interpreted to be between fair weather and storm wave base. Tempestites are primarily identified in the rock record by hummocky cross-stratification (HCS). HCS is a typical indicator of oscillatory flow in subaqueous settings, where strong wave action can scour and redeposit sediment. Tempestites may also contain sole marks and various forms of ripples. Some work has been done on tempestites in lower shoreface and carbonate ramp settings, but little research has been done on tempestites in very shallow water to …


Analyzing Panama Water Resources Using Radar Topography And Gps, Tim Klug Apr 2015

Analyzing Panama Water Resources Using Radar Topography And Gps, Tim Klug

Research Horizons Day Posters

No abstract provided.


Characterizing The Tgf-Lightning Relationship Using Entln, Kareem Omar Apr 2015

Characterizing The Tgf-Lightning Relationship Using Entln, Kareem Omar

Research Horizons Day Posters

No abstract provided.


Impact Of Desert Dust And Biomass Burning On The Radiative Budget Of The Sahel, Christopher E. Phillips Apr 2015

Impact Of Desert Dust And Biomass Burning On The Radiative Budget Of The Sahel, Christopher E. Phillips

Research Horizons Day Posters

No abstract provided.


River Discharge As Affected By Precipitation, Temperature And Soil Characteristics, Susan Kotikot, Kelly Hodgskins Apr 2015

River Discharge As Affected By Precipitation, Temperature And Soil Characteristics, Susan Kotikot, Kelly Hodgskins

Research Horizons Day Posters

No abstract provided.


Digital Outcrop Model And Paleoecology Of The Eight-Foot Rapid Algal Field (Middle Pennsylvanian Lower Ismay Sequence), Paradox Basin, Utah, Colton Goodrich, Scott Ritter Apr 2015

Digital Outcrop Model And Paleoecology Of The Eight-Foot Rapid Algal Field (Middle Pennsylvanian Lower Ismay Sequence), Paradox Basin, Utah, Colton Goodrich, Scott Ritter

Journal of Undergraduate Research

Although phylloid algal mounds have been studied for 50 year, much remains to be determined concerning the ecology and sedimentology of these Late Paleozoic carbonate buildups. Herein we perform a digital outcrop study of the well-known Middle Pennsylvanian Lower Ismay mound interval in the Paradox Basin because 1) the concept of phylloid algae was established in this interval and 2) outcropping mounds along the San Juan River are cited as outcrop analogs of reservoir carbonates in the Paradox Basin oil province of Utah and adjacent states. The principal field area is the Eight Foot algal field located at river mile …


The Impact Of Stegastes Planifrons On The Resurgence Of Acropora Cervicornis, Zebulon Martin Apr 2015

The Impact Of Stegastes Planifrons On The Resurgence Of Acropora Cervicornis, Zebulon Martin

Undergraduate Distinction Papers

This study examines resurgent patches of Acropora cervicornis in the “Coral Gardens” back-reef area of Ambergris Caye, Belize. The goal of this study was to understand the carbonate budget and ecosystem dynamics of this successful reef, with an emphasis on the role of Stegastes planifrons (the herbivorous threespot damselfish), on the health of the coral. Benthic survey data from photo-quadrats along six transects were supplemented with counts of S. planifrons, their chimney scars, and sea urchin (Echinometra viridis) to assess their impact on the reef. The data indicate a positive correlation between the density of Stegastes …


A Tectonic Origin For Mountains On Saturn’S Moon Titan, Jani Radebaugh Apr 2015

A Tectonic Origin For Mountains On Saturn’S Moon Titan, Jani Radebaugh

Journal of Undergraduate Research

In this proposal, we proposed to: (1) undertake a global study of peak heights and slopes of mountains on Titan to determine the relative importance of tectonism and erosion, and thereby gain a better understanding of the timing of mountain formation and subsequent evolution by erosion. We also proposed to: (2) complete general global and detailed regional structure maps to investigate the orientation of forces required to build the selected mountains. We will investigate the role of liquids in the lithosphere in fault propagation and mountain formation, similar to Critical Wedge Theory, explored extensively on Earth. Finally, we planned to: …


Uncertainty In Simulating Gross Primary Production Of Cropland Ecosystem From Satellite-Based Models, Wenping Yuan, Wenwen Cai, Anthony L. Nguy-Robertson, Huajun Fang, Andrew E. Suyker, Yang Chen, Wenjie Dong, Shuguang Liu, Haicheng Zhang Apr 2015

Uncertainty In Simulating Gross Primary Production Of Cropland Ecosystem From Satellite-Based Models, Wenping Yuan, Wenwen Cai, Anthony L. Nguy-Robertson, Huajun Fang, Andrew E. Suyker, Yang Chen, Wenjie Dong, Shuguang Liu, Haicheng Zhang

School of Natural Resources: Faculty Publications

Accurate estimates of gross primary production (GPP) for croplands are needed to assess carbon cycle and crop yield. Satellite-based models have been developed to monitor spatial and temporal GPP patterns. However, there are still large uncertainties in estimating cropland GPP. This study compares three light use efficiency (LUE) models (MODIS-GPP, EC-LUE, and VPM) with eddy-covariance measurements at three adjacent AmeriFlux crop sites located near Mead, Nebraska, USA. These sites have different croprotation systems (continuous maize vs. maize and soybean rotated annually) and water management practices (irrigation vs. rainfed). The results reveal several major uncertainties in estimating GPP which need to …


Early Miocene Antarctic Glacial History: New Insights From Heavy Mineral Analysis From Andrill And–2a Drill Core Sediments, Francesco Iacoviello, Giovanna Giorgetti, Isabella Turbanti Memmi, Sandra Passchier Apr 2015

Early Miocene Antarctic Glacial History: New Insights From Heavy Mineral Analysis From Andrill And–2a Drill Core Sediments, Francesco Iacoviello, Giovanna Giorgetti, Isabella Turbanti Memmi, Sandra Passchier

ANDRILL Research and Publications

The present study deals with heavy mineral analysis of late Early Miocene marine sediments recovered in the McMurdo Sound region (Ross Sea, Antarctica) during the ANDRILL— SMS Project in 2007. The main objective is to investigate how heavy mineral assemblages reflect different source rocks and hence different provenance areas. These data contribute to a better understanding of East Antarctica ice dynamics in the Ross Sea sector during the Early Miocene (17.6–20.2 Ma), a time of long-term global warming and sea level rise. The AND-2A drill core recovered several stratigraphic intervals that span from Early Miocene to Pleistocene and it collected …


Remote Sensing Of Beachrock And Other Geomorphological Indicators Of Sea-Level Rise On Lesvos, Greece, Frankie St. Amand Apr 2015

Remote Sensing Of Beachrock And Other Geomorphological Indicators Of Sea-Level Rise On Lesvos, Greece, Frankie St. Amand

Thinking Matters Symposium Archive

While research has shown the possibility of seafloor mapping at depths of up to 30m, a number of factors restrict exploration of bathymetry such as pixel size, sun azimuth, season, water turbidity and suspended sediments, as well as seafloor topography13. Though the 30m composite images of Lesvos were able to penetrate shallow water to expose submerged features, pixel size prevented mapping of beachrock outcrops because they couldn’t be differentiated from other sediments or underwater features. Higher resolution aerial images enabled accurate beachrock mapping. These images were obtained by a helicopter but increasingly, remote drones are a cost effective way of …


An Investigation To Remotely Sense Mineral Leeching Through Soils, Paul C. Shaffer Apr 2015

An Investigation To Remotely Sense Mineral Leeching Through Soils, Paul C. Shaffer

Thinking Matters Symposium Archive

Satellite data on Earth's surface provide a wealth of information on landscape conditions. I use Landsat data to determine an important geologic process that influences the composition of the soils. My project focusses on the experimental hypothesis that we can use plant vigor as a proxy to document mineral washing downslopes through soils. I constructed a Normalized Difference Vegetation Index (NDVI) composite image from Landsat data to help assess vegetation heath in my target location - a national park south of Mount St. Helens. This location was selected because of its steep inclines, dense undisturbed vegetation, and fertile soils. It …


Habitat Fragmenta-On In The Sebago Lake Watershed, Jared Lank Apr 2015

Habitat Fragmenta-On In The Sebago Lake Watershed, Jared Lank

Thinking Matters Symposium Archive

The goal of this research was to evaluate the extent of land use change occurring in the Sebago lake watershed of southern Maine. The primary data set used was Landsat 7 Near Infrared satellite imagery of the region which was analyzed with ESRI’s ArcGIS soQware. Data was clipped to the Portland Water District’s sub watershed shape file and analyzed with the soQware’s image analysis ‘difference’ tool which calculates the differences in pixel values between to raster datasets. The 2013 Landsat reclassifica-on was compared to 1987, 1995 and 2009 reclassifica-ons. NOAA’s Habitat Priority Planner plugin tool was also u-lized in order …


Glowing Seashells: Diversity Of Fossilized Coloration Patterns On Coral Reef-Associated Cone Snail (Gastropoda: Conidae) Shells From The Neogene Of The Dominican Republic, Jonathan R. Hendricks Apr 2015

Glowing Seashells: Diversity Of Fossilized Coloration Patterns On Coral Reef-Associated Cone Snail (Gastropoda: Conidae) Shells From The Neogene Of The Dominican Republic, Jonathan R. Hendricks

Faculty Publications

The biology of modern Conidae (cone snails)—which includes the hyperdiverse genus Conus—has been intensively studied, but the fossil record of the clade remains poorly understood, particularly within an evolutionary framework. Here, ultraviolet light is used to reveal and characterize the original shell coloration patterns of 28 species of cone snails from three Neogene coral reef-associated deposits from the Cibao Valley, northern Dominican Republic. These fossils come from the upper Miocene Cercado Fm. and lower Pliocene Gurabo Fm., and range in age from about 6.6-4.8 Ma. Comparison of the revealed coloration patterns with those of extant species allow the taxa to …


Should Nuclear Energy Be More Heavily Incorporated By The United States?, Matthew Romer Apr 2015

Should Nuclear Energy Be More Heavily Incorporated By The United States?, Matthew Romer

Nebraska College Preparatory Academy: Senior Capstone Projects

America is involved in one of the biggest races towards electrical efficiency, cleanliness, and productivity. Nuclear energy is a major part of the U.S.’s non-­‐carbon emitting electricity, and has strict regulations for management. However, this form of energy has been on the decline in the past couple decades due to cost and competition with cheaper, less clean methods. Is nuclear energy feasible enough to continue?


Climate Change Impact Assessments Using The Water Erosion Prediction Project Model, Joseph Trotochaud Apr 2015

Climate Change Impact Assessments Using The Water Erosion Prediction Project Model, Joseph Trotochaud

Open Access Theses

This study was conducted to develop a simplified method of obtaining future climate data inputs for natural resource models and apply that method to three locations within the continental United States to assess the effect of climate change on soil erosion, runoff, and fire risk. A method was developed for quickly obtaining future climate data over a wide range of scenarios, General Circulation Models (GCMs), and timescales from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) and Fifth Assessment Report (AR5) model families using the MarkSim® DSSAT Weather Generator and a Microsoft Excel VBA Macro, the …


The Promise And Peril Of Intensive-Site-Based Ecological Research: Insights From The Hubbard Brook Ecosystem Study, Timothy J. Fahey, Pamela H. Templer, Bruce T. Anderson, John J. Battles, John L. Campbell, Charles T. Driscoll, Anthony R. Fusco, Mark B. Green, Karim-Aly S. Karrim, Nicholas L. Rodenhouse, Lindsay E. Rustad, Paul G. Schaberg, Matthew A. Vadeboncoeur Apr 2015

The Promise And Peril Of Intensive-Site-Based Ecological Research: Insights From The Hubbard Brook Ecosystem Study, Timothy J. Fahey, Pamela H. Templer, Bruce T. Anderson, John J. Battles, John L. Campbell, Charles T. Driscoll, Anthony R. Fusco, Mark B. Green, Karim-Aly S. Karrim, Nicholas L. Rodenhouse, Lindsay E. Rustad, Paul G. Schaberg, Matthew A. Vadeboncoeur

All Materials

Abstract.

Ecological research is increasingly concentrated at particular locations or sites. This trend reflects a variety of advantages of intensive, site-based research, but also raises important questions about the nature of such spatially delimited research: how well does site based research represent broader areas, and does it constrain scientific discovery?We provide an overview of these issues with a particular focus on one prominent intensive research site: the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA. Among the key features of intensive sites are: long-term, archived data sets that provide a context for new discoveries and the elucidation of ecological mechanisms; …