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Litterfall, Biomass and Productivity in CRUI Land Use Project at Harvard Forest 1996-1997

Prior agricultural land use often plays an important role in the present condition of forests. This research was conducted to find any productivity differences among previously plowed, pastured, and woodlot sites. There are six sites, two from each of the land use types. With this research we wanted to estimate the productivity for each of the six stands and test the hypothesis that rates of annual aboveground biomass and annual litter fall in recovering forests would decline in the order woodlot - pastured - plowed. Twenty-five trees, of various diameters and species, were cored at each site. The cores were analyzed and the radial growth was calculated for the most recent 5 and 10 year intervals. Biomass increments were also calculated for the same time span using published allometric equations. Aboveground woody productivity was calculated for diameter classes within species and semi-log relationships of productivity per diameter were used to calculate the productivity of all trees in the stand that were not cored. Site-specific and species-specific equations were used. Litter fall was estimated by collecting litter from ten traps each in the six stands. Litter was sorted by species and reported on a dry matter basis. Red oaks and red maples were the major contributors of biomass and litter fall in all six of the stands, accounting for about seventy percent of the total aboveground biomass. Although woodlots had higher total biomass there was not a significant difference in productivity across the six sites. The range of productivity including both litter fall and aboveground woody production was from 7524-9014 Kg/ha. This fell into the range for temperate forests according to results published by the International Biological Program. Production per unit biomass was greater in the plowed stand and least in the woodlots.

Tree Canopy Leaf Area Index in CRUI Land Use Project at Harvard Forest 1997

Numerous variables related to land use disturbance and recovery processes can influence forest composition and structure. We’ve measured differences in forest communities in six sites that were formerly plowed, pastured, or continuously forested woodlots in Prospect Hill. None of the sites had noticeable canopy gap disturbance at the time of the measurements. Leaf area index (LAI) was measured with an LAI-2000 plant canopy analyzer (Li-Cor, Inc., Lincoln, NE) at all 77 edge and interior intersection points in the 30 m x 50 m permanent plot (7 columns x 11 rows) in 5 of our 6 land use sites. Under-canopy measurements were made in each site over 25-30 minutes during midday hours (11:00-2:30 EST) on overcast days near solstice (June 13, 18). The under-canopy readings were contrasted with an open-sky measurement taken in an open field near the Harvard Forest headquarters just before beginning data collection in each site. LAI averaged 3.98 and ranged from 2.28 to 5.93 across all sites. W1 had the highest site-level mean (4.62) and maximum (5.93) LAI while S2 had the lowest values (mean = 3.41, max = 4.55). The woodlot also showed the greatest spatial variation as measured by C.V., while plow #1 showed the least variation.

Canopy Sky Factors in CRUI Land Use Project at Harvard Forest 1998

Hemispherical photos were taken at 35 interior grid corners in each land use site’s 30 m x 50 m permanent plot on uniformly overcast days during summer 1998. A Canon A-1 35 mm camera with a 7.5 mm lens was mounted on a tripod, positioned so the film plane was 0.5 m above ground, oriented N-S with a compass, and leveled. Ektachrome 100 slide film was used. Two exposures were made for each location. The slides were processed and digitized in jpeg format by Kodak, Inc. at a resolution of 1536 x 1024 dpi. The jpeg images were screened for nearground obstructions. Fifteen of the 35 photo locations per site were used in subsequent analysis. Hemiview software (v. 2.0, Delta-T Devices Ltd., Cambridge, UK) was used to process the images and calculate indirect, direct, and global (= indirect + direct) sky factors for each sample location, plus the proportion of global sky factor represented by direct beam radiation. Several images spanning a wide range of canopy density were used to develop protocols for setting optimal thresholds in converting from color to black and white images. Each B/W image was then analyzed at three threshold levels, the optimum level plus 5 threshold units (~ 2.5%) above and below the optimum. The results were averaged across the three threshold levels to provide one set of sky factor data per sample location. Above-canopy incident radiation was calculated daily for the June-September growing season based on (1) latitude and longitude, (2) average atmospheric transmission, and (3) monthly averages for fractions of the day in diffuse radiation due to cloud cover for the Harvard Forest area. Data for 2 and 3 above were provided by researchers at the State University of New York at Albany. Below-canopy radiation was estimated daily across half-hour intervals as the sum of diffuse and direct beam components. Sky factors were then calculated from the above- and below-canopy radiation values and averaged both monthly and across the growing season.

Herbaceous Species in CRUI Land Use Project at Harvard Forest 1996

Forests recovering from agricultural legacies differ in many ways that influence the landscape distribution, local abundance, and dispersion of herbaceous populations, as well as patterns of species associations within the herbaceous stratum. We recorded the presence/absence of 10 herbaceous species on a 1 x 1 m resolution in a 30 x 50 m permanent plot grid in six land use legacy sites (2 plowed, 2 pastured, 2 permanent woodlot) in summer 1996 to test predictions about herbaceous species abundance, richness, dispersion patterns, patterns of association, and their relationships to forest structure, microclimates, and soil resources. The 10 species chosen differed in several ways (evergreen vs. deciduous, stature, clonal architecture, affinity for disturbed vs. undisturbed forests) that allowed us to probe the impacts of prior disturbance and current resource patterns (light, water, nutrients) on the spatial patterns of individual species and species associations.

Mapped Trees in CRUI Land Use Project at Harvard Forest 1996-2006

Numerous variables related to land use disturbance and recovery processes influence forest composition, structure, and growth. We measured forest communities in six sites that were formerly plowed, pastured, or continuously forested woodlots in Prospect Hill to test predictions about species composition, stand structure, and productivity in response to agricultural land use legacies. A permanent 30 x 50 m plot gridded in 5 x 5 m sub-plots was established in each of the 6 sites. All trees at least 2.5 cm DBH (diameter at breast height, 1.3 m) were mapped visually in the field, marked with an aluminum tag, and their DBH recorded in summer 1996. Individual boles of multi-stemmed trees were measured separately and a composite single DBH was calculated. Standing dead trees were also mapped and their DBH recorded as well. The 1996 data were used to determine above ground woody biomass using allometric equations for individual trees. The permanent plots were re-surveyed ten years later in fall 2006. The status of each tree mapped in 1996 was recorded (alive, dead standing, dead fallen, forked) and DBH’s were re-measured. Additional trees that grew across the 2.5 cm DBH threshold during the ten-year period were mapped and their DBH’s measured. Composite diameters and above ground woody biomass were determined for forked trees as in 1996. The 2006 re-measurements were used to analyze changes in species composition, stand structure (density, diameter distribution), and mortality patterns among species and size classes, and to calculate net changes in above ground woody biomass across the ten-year period.

Microclimate in CRUI Land Use Project at Harvard Forest 1997

Understory microenvironmental patterns are strongly influenced by both the forest community and substrate, which are in turn affected by site factors, disturbance history and recovery processes. We measured ground-level microclimates across the growing season as part of a multi-faceted study of soil-plant-atmosphere interactions in sites with different agricultural land-use legacies (formerly plowed, formerly pastured, permanent woodlots) in Prospect Hill. A permanent 30 x 50 m plot was established in each of six sites (2 per land use category) and gridded into 5 x 5 m sub-plots. Fifteen microclimate stations were used to measure photosynthetic photon flux (PPF, umol m-2 s-1, LI-190 quantum sensor, Li-Cor, Inc), soil temperature (107B thermistor, Campbell Scientific, Logan, Utah), and air temperature (107 thermistor, Campbell Scientific, Logan, Utah) at 5 locations each in three sites simultaneously. PPF and air temperature were measured at 50 cm, while soil temperature was measured 5 cm. The central sample station was located in the center (sub-plot D6) of the 30 x 50 m grid and four additional stations were positioned 10 m from the central station in the cardinal directions. In addition to the variables described above, relative humidity (%, 207 air temperature/relative humidity probe, Campbell Scientific, Logan, Utah) was measured at 50 cm at the central station. All sensors were connected to a Campbell Scientific 23X datalogger and sampled continuously every 10 sec and averaged every 10 minutes for 5 days at a time. The stations were switched between two sets of sites (P1-S2-W2 followed by P2-S1-W1) at the end of every week, so the data record for any one site includes alternate weeks. Measurements were made during April through September, 1997. The data archived here are daily means per variable per station. Missing records are due to inclement weather, while blank fields represent occasional sensor or datalogger connection problems.

Photosynthetic Light Response Curves in CRUI Land Use Project at Harvard Forest 1998

Ambient CO2 concentrations in terrestrial ecosystems vary substantially on several spatial and temporal scales as numerous soil, plant, and atmospheric processes respond to irradiance, temperature, moisture and wind. There is one widespread microhabitat in terrestrial ecosystems, the nearground zone, in which CO2 is naturally enhanced above average background levels. CO2 produced by soil respiration diffuses through the litter and boundary layers and dissipates fairly rapidly into the overlying bulk air. However, a marked vertical profile of nearground enriched CO2 (hereafter NEC) is usually present in the first 0-50 cm above ground. The degree of enrichment varies primarily with soil respiration rate and turbulent mixing, secondarily with photosynthesis by plants in the herbaceous stratum, and usually shows marked diel and seasonal variation. References to this CO2 "subsidy" and its effects on plants have occurred occasionally in the literature since 1939, but there have been few detailed studies of either the nearground profile or plant responses in the field, particularly for species that consistently occupy the nearground stratum. Considerable research over the last twenty years in both controlled and field environments has shown that co-occurring plant species may respond differently to artificially elevated CO2. But in contrast to light, temperature, water, and nutrients, plant community ecologists have generally not considered CO2 among the factors that regulate species’ distribution and abundance, except indirectly as it may affect water balance. We have documented differences in forest composition (woody and herbaceous), soil characteristics, microclimates, and nearground CO2 levels among six sites that were formerly plowed, pastured, or continuously forested woodlots in Prospect Hill. We selected three perennial herbaceous species (Aralia nudicaulis, wild sarsaparilla; Clintonia borealis, blue-bead lily; Medeola virginiana, Indian cucumber root) and two do

Herbaceous Stratum Sunfleck Regimes in CRUI Land Use Project at Harvard Forest 1998

Numerous variables related to land use disturbance and recovery processes can influence forest understory irradiance regimes. In addition to season-long measurements of herbaceous stratum microclimates (data archived separately), we explored the degree to which differences in forest community composition and structure generate differences in near-ground sunfleck regimes in our six land use sites (2 plowed, 2 pastured, 2 permanent woodlot). Considerable research has shown that photosynthetic responses to fluctuating irradiance cannot be predicted accurately from steady-state gas-exchange measurements, and that sunflecks may account for both a large fraction of total daily photon fluence and net carbon assimilation by plants in the herbaceous stratum of moist forests. We measured clear-day irradiance patterns to test predictions about how sunfleck frequency, duration, and brightness should vary across the three land-use legacies. We also wished to document sunfleck regimes as part of a companion study on photosynthetic responses by herb and tree species to sunflecks. Twenty-three quantum sensors (Li-190, Li-Cor, Inc., Lincoln, NE) were placed at regularly-spaced interior intersection points across the 30 m x 50 m permanent plot grid in each land use site. The sensors were mounted on stakes 50 cm above ground, leveled, and attached to a Campbell Scientific CR23X datalogger. Photosynthetic photon flux (PPF) values were recorded at all 23 microsites every 6 seconds for 3.5-4.5 hours in the morning (8:00-11:30+ a.m. EST) on one clear day per site in July and August 1998. Using custom software and a sunfleck definition threshold of 100 umol m-2 s-1, sunfleck events were extracted for each microsite across the sampling period and the following were calculated for each fleck event: number of fleck events per hour, sunfleck duration (sec), duration of the shade period prior to the sunfleck (sec), mean PPF across the sunfleck event, and peak PPF during the sunfleck. Descrtipti

Tree Seedlings in CRUI Land Use Project at Harvard Forest 1996

Forests recovering from agricultural legacies differ in many ways that influence tree seed dispersal and seedling establishment patterns. We recorded the number of seedlings (less than 0.5 m tall) of all tree species on a 1 x 1 m resolution across six land use legacy sites (2 plowed, 2 pastured, 2 permanent woodlot) in summer 1996 to test several predictions about seedling abundance, diversity, and dispersion patterns, and their relationships to forest structure, microclimates, and soil resources.

Herbaceous Community Composition in CRUI Land Use Project at Harvard Forest 1996

Patterns of vascular plant species richness were investigated in six land use legacy sites (2 formerly plowed, 2 formerly pastured, and 2 permanent woodlot) in Prospect Hill to test predictions about the effects of disturbance, light and soil resources, and forest floor environmental heterogeneity on community composition. The occurrence of vascular taxa was recorded in each of the 60 5 m x 5 m contiguous plots within the 30 m x 50 m permanently gridded study plot in each land use legacy site in June 1996. Identification was made to species in most cases. Woodlots showed higher average species richness at the site level (53) than either pastured (52 species) or plowed (49) sites. However woodlots also show greater spatial variation in richness at the 5 m x 5 m resolution than either the plowed or pastured sites (in that order) as represented by the range, standard deviation, and coefficient of variation. Seasonally-averaged light levels at 50 cm are approximately twice as high in the plowed and pastured sites as in the woodlots, but the woodlots show significantly greater soil organic matter, carbon, nitrogen and water-holding capacity than the post-agricultural sites. These results suggest that soil resources may be more important than light in fostering higher herbaceous stratum richness. However, woodlot richness is also affected by the presence of taxa that are slow to re-colonize heavily disturbed sites (e.g., Epigaea repens) and to distinctive microsites that are less common in the plowed or pastured sites in the Harvard Forest system (e.g., exposed boulders). The greater spatial variation in woodlot richness is strongly influenced by both substrate diversity and by scattered hemlock trees, which substantially depress the herb stratum in localized patches.

openCC0Nov 2023View details →

Land Use and Forest Dynamics at Harvard Forest 1937-2013

Modern vegetation patterns have developed as a result of species response to environmental gradients, disturbance history, and biotic interactions. However, the relative importance of environmental versus historical factors in determining modern species distributions may differ from site to site and may change with increasing time since disturbance. In addition, life-forms may differ in their response to environmental versus historical disturbance gradients. In the current study, we relate vegetation patterns across the Prospect Hill Tract of Harvard Forest to variability in edaphic factors and disturbance histories. Modern species distribution patterns are related to both edaphic and disturbance gradients. Although species respond individualistically to edaphic and disturbance gradients, land-use history, soil drainage, and C:N ratio are good predictors of the distribution of many species. In contrast, 1938 hurricane damage is less important. Vascular species richness is related to historical land-use, with fewer species in historical woodlots than on former agricultural sites. This is contrary to what has been reported from several other studies, and may reflect the dominance of historical woodlots in the study area by hemlock, a species that creates environmental (i.e. light and soil) conditions that are unsuitable for many species. Historical land-use does not appear to influence bryophyte species richness, although the distributions of several species do follow patterns of land-use. Species richness also varies according to soil drainage, with higher bryophyte, herb, and shrub richness and lower overstory and understory tree richness on wetter sites.

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Soil Properties in CRUI Land Use Project at Harvard Forest 1995-1998

Soil properties and processes were evaluated on three types of colonial agricultural land-use - plowing, pasturing, and selective tree removal in a woodlot that ceased in the mid to late 1800s. Plowing, the most intensive type of agricultural disturbance, mixes soil to a depth of approximately 15cm, homogenizing the soil resources and likely reducing diversity in microenvironments. Removing trees and replacing them with grasses for pasture decreases the organic matter amount and types of inputs to the system, decreasing resource diversity. Woodlots, altered by selective and chronic tree removal, would have more limited decreases in resources and microenvironments. This study defines forest soil legacies using data from plots located at Harvard Forest in both amounts of soil resources and spatial heterogeneity of those soil resources. We found that for several soil parameters measured on previously cultivated and preciously pastured lands at the Harvard Forest, a legacy exists in the mineral soil, but the forest floor appears to have largely recovered from the agricultural disturbance. Parameters examined included soil mass, bulk density, organic matter content, pH, C, N, nitrogen mineralization and nitrification, Ca, Mg, K, and P.

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Soil Respiration in CRUI Land Use Project at Harvard Forest 1997

Soil properties and processes were evaluated on three types of colonial agricultural land-use - plowing, pasturing, and selective tree removal in a woodlot that ceased in the mid to late 1800s. Plowing, the most intensive type of agricultural disturbance, mixes soil to a depth of approximately 15cm, homogenizing the soil resources and likely reducing diversity in microenvironments. Removing trees and replacing them with grasses for pasture decreases the organic matter amount and types of inputs to the system, decreasing resource diversity. Woodlots, altered by selective and chronic tree removal, would have more limited decreases in resources and microenvironments. This study examined soil surface (at 10cm above the soil surface) CO2 concentrations and soil respiration at the land use sites. Soil respiration and surface CO2 concentrations were highest in the woodlot sites and lowest in the formerly plowed sites.

opencc-by-4.0Jun 2024View details →

zenodo52/100

Parsimonious Random-Forest-Based Land-Use Regression Model Using Particulate Matter Sensors in Berlin, Germany

The dataset consists of particulate matter pollution concentration, measured in three localities - Hermsdorf, Charlottenburg and Adlershof, in Berlin, Germany. <a href="../api/records/10076056/draft/files/pm25_summer_rd_30s.geojson/content" target="_blank" rel="noopener noreferrer">pm25_summer_rd_30s.geojson</a> shows the observed PM2.5 concentration in a 30 second interval. <a href="../api/records/10076056/draft/files/pm25_summer.geojson/content" target="_blank" rel="noopener noreferrer">pm25_summer.geojson</a> shows the concentrations shown is the local concentration (observed concentration - background concentration) in a 30 second interval. The background concentration is calculated as the lowest 5 percentile of the measured concentration for each measurement round.  <a href="../api/records/10076056/draft/files/PM2.5_lc_max.geojson/content" target="_blank" rel="noopener noreferrer">PM2.5_lc_max.geojson</a> contains the information from <a href="../api/records/10076056/draft/files/pm25_summer.geojson/content" target="_blank" rel="noopener noreferrer">pm25_summer.geojson</a> in a 25m resolution. Additionally, it contains the land use information for each coordinate. The original publication providing all necessary background information on study sites, methodology and data processing is the following: Venkatraman Jagatha, J., T. Sauter, C. Schneider (2024): Parsimonious Random-Forest-Based Land-Use Regression Model Using Particulate Matter Sensors in Berlin, Germany. MDPI Sensors, 24(13), 4193, DOI: 10.3390/s24134193. The paper is fully open access and can be downloaded at <a href="https://doi.org/10.3390/s24134193">https://doi.org/10.3390/s24134193</a>. Information on working with geojson file can be found under <a href="https://geojson.readthedocs.io/en/latest/">GeoJSON</a> .

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Land cover, landscape metrics and typology of European cities for Urban Forest Ecosystem Services (UFES) evaluation

The data refers to the paper "Urban Forests as Regulating Ecosystems: Types and Ranking of European Cities" The datasets provide a typology for 689 European urban areas, the land cover metrics and landscape metrics used to create the typology and the Urban Forest Ecosystem Services (UFES) indexes created from them. The typology of Urban Forest Ecosystem Services (UFES) presents 10 clusters of cities aggregated into 4 groups: Forest cities, Anthropogenic cities, Herbaceous cities and Standard European cities. The data can be used to support urban planning policies at local and regional scales; in urban forestry, urban form and ecosystem services work related at different spatial scales. The metrics used capture the spatial integration of different layers of natural, semi-natural and artificial land within functional urban areas.   The datasets are a csv file (<code>Metrics.csv</code>) and a shapefile (<code>UFES.shp</code>) of polygons with attributes. <ul> <li> <code>UFES.shp</code> attributes' are the following: FUA codes, country name, main city name, clusters and groups of FUAs resulting from the hierarchical cluster analysis (HCA), the R color codes used in the article, the five UFES budget indexes as well as an aggregated global UFES index for each FUA. </li> <li> <code>Metrics.csv</code> contains the FUA codes, the land cover and landscape metrics used in the HCA. </li> </ul>

opencc-by-4.0Dec 2020View details →

openCustomMar 2014View details →

Land use designations, Andrews Experimental Forest, 1998-2011

Land use designations for the Andrews Experimental Forest including the headquarters site, late successional reserves (LSR) from the Northwest Forest Plan designations, designated control areas, quarry locations, and areas potentially suitable for experiments. The designated control areas and potentially suitable for experiences areas were identified in 1998. Quarry locations were updated in 2011. The data were gathered from a variety of source data (NW Forest Plan designations for Willamette National Forest, identification of sites from digital orthophotography, and from maps drawn by Andrews staff).

The effects of agricultural land-use history on non-native plant invasion in Bent Creek Experimental Forest in 2006

The researchers considered the effects of agricultural land-use legacies on the distribution of non-native invasive plants a century after abandonment in a watershed in western North Carolina, USA. The study was conducted at the Bent Creek Experimental Forest (BCEF) 15 km southwest of Asheville, North Carolina, USA, in the Pisgah National Forest. Forest sites that were previously in cultivation and abandoned ca. 1905 were compared with nearby reference sites that were never cultivated. The most common invasive plants were Celastrus orbiculatus Thunb., Microstegium vimineum Trin., and Lonicera japonica Thunb. (Kuhman, Pearson, and Turner 2011). Disentangling the cause–effect relationships between land-use history, the biotic community, and the abiotic template presents a challenge, but understanding the role of land-use legacies may provide important insights regarding the mechanisms underlying the establishment and spread of invasive plants in forest ecosystems (Kuhman, Pearson, and Turner 2011). A total of 86 plots were established at Bent Creek Experimental Forest during the summer of 2006. Specifically, the study was conducted between June and August 2006. Half of these were established in historic agricultural plots and half in reference plots that were not formerly used for agriculture (pasture or rowcrops) based on the 1941 Forest Service Report by William Nesbitt and the appended land-use history map (History of early settlement and land use on the Bent Creek Experimental Forest Buncombe County, NC. 1941). Historic agriculture and reference plots were paired based on similarities in topography and bedrock geology (typically in relatively close proximity to one another). Within sites, two plots were established, one adjacent to the road and one 50 m away from the road (labeled as "A" and "B", respectively, in the "Plot #").

Does land-use history facilitate non-native plant invasion? A field experiment with Celastrus orbiculatus in the Bent Creek Experimental Forest in the southern Appalachians from 2008 to 2009

Although historic land use is often implicated in non-native plant invasion of forests, little is known about how land-use legacies might actually facilitate invasion. The researchers conducted a 2-year field seeding experiment in western North Carolina, USA, to compare germination and first-year seedling survival of Celastrus orbiculatus Thunb. in stands that had been cultivated and abandoned a century earlier and were dominated by tulip poplar (Liriodendron tulipifera L.), and in paired stands that had never been cultivated and were dominated by oaks (Quercus spp.). Experiments were conducted at five sites with paired tulip poplar and oak stands by varying litter mass (none, low, or high) and litter type (tulip poplar or oak).

Year 2001, 15 minute measurements of stage, water temperature, conductivity, dissolved oxygen, and pH in a small headwater stream draining a moderate sized, mixed land use (mainly forest) watershed, Fish Brook, Middleton, MA.

During 2001, continuous measurements, every 15 minutes, were made of stage, water temperature, conductivity, dissolved oxygen, and pH in a small headwater stream, Fish Brook, Boxford, MA, draining a moderate sized, mixed land use watershed. Measurements are for part of the ice free season (June – December). Discharge could not be determined due to inadequate rating curve. Several day gaps occur periodically due to removal for recalibration.

Year 2002, 15 minute measurements of stage, water temperature, conductivity, dissolved oxygen, and pH in a small headwater stream draining a moderate sized, mixed land use (mainly forest) watershed, Fish Brook, Middleton, MA.

During 2002, continuous measurements, every 15 minutes, were made of stage, water temperature, conductivity, dissolved oxygen, and pH in a small headwater stream, Fish Brook, Boxford, MA, draining a moderate sized, mixed land use watershed. Measurements are for part of the ice free season (June – December). Discharge could not be determined due to inadequate rating curve and due to beaver activity. Several day gaps occur periodically due to removal for recalibration.