Broadleaf Sites Research Articles

Interannual variability and seasonality of litterfall in three temperate and boreal forest ecosystems of eastern Canada: A synthesis of long-term monitoring

Litterfall is a major pathway for transferring aboveground biomass to the forest floor and thus plays an important role in building forest soil carbon stocks. However, inter- and intra-annual variability of litterfall remains poorly documented, especially in North American temperate and boreal forests, due to the lack of recent long-term studies at high sampling frequencies. This potentially creates uncertainties in estimates of forest carbon budget models. The objectives of the present study were to 1) quantify the mean annual flux, interannual variability, and seasonality of litterfall in three sites (dominated respectively by sugar maple (Acer saccharum Marsh.), balsam fir (Abies balsamea (L.) Mill. 1768), and black spruce (Picea mariana (Mill.) B.S.P.)) in eastern Canada over a period of 22–32 years, 2) relate the litterfall amounts and temporal variations to the changes in the size of major organic matter pools in these ecosystems, and 3) compare our litterfall estimates with reference values used in national greenhouse gas inventories. Litterfall production decreased from the sugar maple to the balsam fir and black spruce sites, preponderantly due to species composition. Litterfall evolution was related to the aboveground biomass of live trees in both conifer sites; in contrast, in the broadleaf site, changes in forest composition and structure were apparently the main drivers. The litterfall seasonality varied between broadleaf and conifer sites and could be explained by a sigmoidal model. Substantial departures from the seasonality for some given years were likely due to important climatic anomalies. Forest floor biomass remained stable over time at all three sites despite the increase in litterfall at the balsam fir and sugar maple sites and rapid forest floor turnover at the latter site. Our analyses of litterfall suggest that reference values from the literature used for national greenhouse gas inventories underestimate annual litterfall and forest floor carbon stocks for temperate and boreal forests.

Predicting spring phenology in deciduous broadleaf forests: NEON phenology forecasting community challenge

Accurate models are important to predict how global climate change will continue to alter plant phenology and near-term ecological forecasts can be used to iteratively improve models and evaluate predictions that are made a priori. The Ecological Forecasting Initiative's National Ecological Observatory Network (NEON) Forecasting Challenge, is an open challenge to the community to forecast daily greenness values, measured through digital images collected by the PhenoCam Network at NEON sites before the data are collected. For the first round of the challenge, which is presented here, we forecasted canopy greenness throughout the spring at eight deciduous broadleaf sites to investigate when, where, and for what model type phenology forecast skill is highest. A total of 192,536 predictions were submitted, representing eighteen models, including a persistence and a day of year mean null models. We found that overall forecast skill was highest when forecasting earlier in the greenup curve compared to the end, for shorter lead times, for sites that greened up earlier, and when submitting forecasts during times other than near budburst. The models based on day of year historical mean had the highest predictive skill across the challenge period. In this first round of the challenge, by synthesizing across forecasts, we started to elucidate what factors affect the predictive skill of near-term phenology forecasts.

Organic litter dynamics in headwater streams draining contrasting land uses

Climate change could alter fluxes of organic matter and macronutrients through freshwater ecosystems potentially affecting stream organisms. However, riparian controls on litter dynamics offer an opportunity to adapt headwaters to climate change by protecting or restoring riparian vegetation. We assessed how riparian land cover and climatic variability affected the supply, retention and downstream transport of particulate organic matter (POM) in headwaters—the most extensive small water bodies in temperate landscapes. Leaf litter inputs, benthic stocks and suspended organic matter were measured nominally monthly in second–third-order streams draining broadleaf woodland, conifer, acid moorland and circumneutral moorland over four years with varying discharge. Streams draining broadleaf woodland received more leaf litter from the riparian zone than conifer and moorland and transported higher concentrations of CPOM and FPOM at base flows. Broadleaf sites had higher CPOM stocks, even after hydrological events that reduced CPOM in conifer and moorland sites. In contrast, FPOM dynamics reflected hydrological conditions irrespective of land cover. These results show how some organic matter fractions in streams are sensitive to hydrological conditions, illustrating how wetter climates will influence FPOM exports. Nevertheless, riparian broadleaves have the potential to offset climatic effects on organic matter processing in headwaters through the replenishment and retention of CPOM.

A Statistical Model for Estimating Midday NDVI from the Geostationary Operational Environmental Satellite (GOES) 16 and 17

The newest version of the Geostationary Operational Environmental Satellite series (GOES-16 and GOES-17) includes a near infrared band that allows for the calculation of normalized difference vegetation index (NDVI) at a 1 km at nadir spatial resolution every five minutes throughout the continental United States and every ten minutes for much of the western hemisphere. The usefulness of individual NDVI observations is limited due to the noise that remains even after cloud masks and data quality flags are applied, as much of this noise is negatively biased due to scattering within the atmosphere. Fortunately, high temporal resolution NDVI allows for the identification of consistent diurnal patterns. Here, we present a novel statistical model that utilizes this pattern, by fitting double exponential curves to the diurnal NDVI data, to provide a daily estimate of NDVI over forests that is less sensitive to noise by accounting for both random observation errors and atmospheric scattering biases. We fit this statistical model to 350 days of observations for fifteen deciduous broadleaf sites in the United States and compared the method to several simpler potential methods. Of the days 60% had more than ten observations and were able to be modeled via our methodology. Of the modeled days 72% produced daily NDVI estimates with <0.1 wide 95% confidence intervals. Of the modeled days 13% were able to provide a confident NDVI value even if there were less than five observations between 10:00–14:00. This methodology provides estimates for daily midday NDVI values with robust uncertainty estimates, even in the face of biased errors and missing midday observations.

Efficient hyper-parameter determination for regularised linear BRDF parameter retrieval

ABSTRACTLinear kernel driven models of the surface Bidirectional Reflectance Distribution Function (BRDF) are valuable tools for exploiting Earth observation data acquired at different sun–sensor geometries. Here we present a method that efficiently determines linear BRDF model weights using Tikhonov smoothing where the smoothing parameter λ is determined via a Generalized Singular Value Decomposition with the root mean square error prescribed depending on the MODIS band. We applied this method to twenty-six different deciduous broadleaf sites across an entire year using the MODIS Terra and Aqua reflectance data products. Kernel weights and white sky albedo derived from this GSVD method were generally consistent with those provided by the MCD43 data products. The GSVD derived results had less sample variability compared to the MCD43 data products, attributable to the assumed smoothness between kernel weights in the Tikhonov smoothing method. The GSVD technique consistently outperforms MCD43 in the reconstruction of observed MODIS reflectance data, of which retrievals from this method will do a better job of estimating albedo and normalizing data to specified geometries.

Negative Trade-offs Between Community Forest Use and Hydrological Benefits in the Forested Catchments of Nepal's Mid-hills

Widespread community forestry practices in Nepal's mid-hills catchments involve removal of forest products—including firewood, litter, fodder, and medicinal herbs—by the local communities. Uncertainty is growing about how sustainable the management of these catchments is and whether it can meet traditional needs and maintain ecosystem services, particularly water. As part of a broader study on the hydrological effects of community forestry practices, we measured selected soil properties, including saturated hydraulic conductivity (Ks), bulk density (BD,) and soil organic carbon (SOC) across 4 depths (0–10, 10–20, 20–50 and 50–100 cm) in 3 types of community forest sites—broadleaf, pine-dominated, and mixed—in the Roshi Khola catchment of Kavre district. The same measurements were made at a minimally disturbed religious forest site in the catchment that had higher Ksvalues than the mixed and broadleaf sites, signifying a lower degree of forest use-related disturbance. Likewise, SOC values for the religious forest were significantly higher (P < 0.05) and BD values significantly lower than the pine-dominated and mixed forest sites, particularly at shallower depths (0–50 cm). Importantly, comparison of the median Ksvalues (16–98 mm h–1) with rainfall intensities measured at the catchment showed the less intensively used pine-dominated site to be conducive to vertical percolation with possible greater contributions to subsurface storage even during high-intensity rainfall events. These results highlight the critical role of forest use practices in landscape hydrology and have implications for the management of the forested catchments in the broader Himalayan region, particularly in relation to the negative local perceptions of the role of pine plantations on declining water resources.

Sex‐specific population dynamics of ocelots in Belize using open population spatial capture–recapture

AbstractWe used open population, spatial capture–recapture (SCR) models to estimate sex‐specific density, survival, per capita recruitment, and population growth rate of ocelots (Leopardus pardalis) at five sites in Belize with up to 12 yr of data per site. Open population SCR models enabled us to separate survival and recruitment from migration using an ecologically realistic, spatially explicit movement model. Yearly survival probability across 4 broadleaf forest sites was estimated at 0.73–0.84 for males and 0.81–0.87 for females, with no clear indication of sex differences. Yearly per capita recruitment was estimated across four broadleaf forest sites at 0.06–0.08 recruits/N for males and 0.09–0.12 recruits/N for females, again with no clear indication of sex differences. At a pine forest site with a population comprised largely of males, survival and recruitment estimates were similar to the broadleaf sites. Population densities in the broadleaf forest sites ranged from 6.5 to 14.7 ocelots/100 km2, and 0.9–2.5 ocelots/100 km2 in the pine forest site, with strong evidence of a female‐biased sex ratio in the broadleaf sites and a male‐biased sex ratio in the pine forest site. We also found strong evidence that female within‐year space use at the broadleaf sites was smaller than that of males, and that within‐year space use at the pine forest site was larger than that at broadleaf sites. Between‐year home‐range relocation at broadleaf sites was of a similar spatial scale as within‐year space use, consistent with philopatry. We found evidence of a small population decline (posterior probability &gt; 0.9) at two of four broadleaf sites; however, given the level of uncertainty about decline magnitudes, we suggest continued monitoring of these sites to increase site‐years and gain further precision on population growth rate estimates. Estimating demographic parameters at large spatial and temporal scales is important for establishing reliable baseline estimates for future comparison and for understanding changes in population dynamics. Long‐term data sets like those we collected are of particular importance for long‐lived species living at low densities and large spatial scales, where not many individuals are exposed to capture in any one year.

The metric matters when assessing diversity: Assessing lepidopteran species richness and diversity in two habitats under different disturbance regimes.

How we measure diversity can have important implications for understanding the impacts of anthropogenic pressure on ecosystem processes and functioning. Functional diversity quantifies the range and relative abundance of functional traits within a given community and, as such, may provide a more mechanistic understanding of ecosystems. Here, we use a novel approach to examine how lepidopteran richness and diversity, weighted by species abundance, differ between habitats under different disturbance regimes (highly disturbed non‐native plantations and less disturbed broadleaf woodlands), both with and without constraining by similarity due to shared taxonomy or functional traits. Comparisons of diversity between the two habitats differed according to which metric was being used; while species richness was 58% greater in broadleaf woodlands, after accounting for species similarity due to shared functional traits, there was little difference between woodland types under two different disturbance regimes. Functional diversity varied within the landscape but was similar in paired broadleaf and plantation sites, suggesting that landscape rather than local factors drive biotic homogenization in plantation dominated landscapes. The higher richness in broadleaf sites appears to be driven by rare species, which share functional traits with more common species. Moth populations in disturbed, plantation sites represent a reduced subset of moth species compared to broadleaf sites, and may be more vulnerable to disturbance pressures such as clear‐felling operations due to low community resilience.

Long‐term monitoring of ocelot densities in Belize

ABSTRACTOcelots (Leopardus pardalis) are listed as least concern on the International Union for Conservation of Nature (IUCN) Red list of Threatened Species, yet we lack knowledge on basic demographic parameters across much of the ocelot's geographic range, including population density. We used camera‐trapping methodology and spatially explicit capture‐recapture (SECR) models with sex‐specific detection function parameters to estimate ocelot densities across 7 field sites over 1 to 12 years (from data collected during 2002–2015) in Belize, Central America. Ocelot densities in the broadleaf rainforest sites ranged between 7.2 and 22.7 ocelots/100 km2, whereas density in the pine (Pinusspp.) forest site was 0.9 ocelots/100 km2. Applying an inverse‐variance weighted average over all years for each broadleaf site increased precision and resulted in average density ranging from 8.5 to 13.0 ocelots/100 km2. Males often had larger movement parameter estimates and higher detection probabilities at their activity centers than females. In most years, the sex ratio was not significantly different from 50:50, but the pooled sex ratio estimated using an inverse weighted average over all years indicated a female bias in 1 site, and a male bias in another. We did not detect any population trends as density estimates remained relatively constant over time; however, the power to detect such trends was generally low. Our SECR density estimates were lower but more precise than previous estimates and indicated population stability for ocelots in Belize. © 2018 The Authors.Journal of Wildlife Managementpublished by Wiley Periodicals, Inc. on behalf of The Wildlife Society.

Optimizing collection methods for noninvasive genetic sampling of neotropical felids

ABSTRACTField‐sampling methods for molecular scatology studies must be optimized, especially when working on elusive species in challenging tropical environments where rates of DNA degradation are elevated because of hot and humid weather conditions. To maximize polymerase chain reaction (PCR) amplification success and genotyping accuracy rates and to minimize genotyping error rates for fecal DNA samples of jaguars (Panthera onca) and co‐occurring Neotropical felids collected in Belize, Central America, we evaluated the performance of two fecal DNA storage techniques (dimethyl sulfoxide saline solution [DETs buffer] and 95% ethanol [EtOH]) suitable for long‐term preservation at remote tropical sites. Additionally, we tested fecal samples collected from 4 different locations on the scat (top, side, bottom, inside) at 2 different tropical forest types (tropical broadleaf and tropical pine forests). DETs buffer was the superior fecal DNA preservation method, with 44% higher PCR amplification success (P = 0.009) and 17% higher genotyping accuracy (P = 0.021) than 95% EtOH‐stored samples. Polymerase chain reaction amplification success of fecal DNA collected at the more open, pine‐forest (Pinus sp.) site differed significantly across locations on the scat, with highest mean success rates obtained from the top (85% ± 6.5% SD), followed by the side (79% ± 9.4% SD), bottom (76% ± 11.9% SD), and inside (69% ± 10.3% SD) of scat samples. Scat samples collected at the more closed‐canopy broadleaf site did not show any significant differences in amplification success rates across scat locations. We recommend that researchers optimize field‐sampling methods, including collection and storage protocols, by conducting a pilot study prior to their molecular scatology research efforts. © 2015 The Wildlife Society.

Impact of model structure and parameterization on Penman–Monteith type evaporation models

Summary The impact of model structure and parameterization on the estimation of evaporation is investigated across a range of Penman–Monteith type models. To examine the role of model structure on flux retrievals, three different retrieval schemes are compared. The schemes include a traditional single-source Penman–Monteith model (Monteith, 1965), a two-layer model based on Shuttleworth and Wallace (1985) and a three-source model based on Mu et al. (2011). To assess the impact of parameterization choice on model performance, a number of commonly used formulations for aerodynamic and surface resistances were substituted into the different formulations. Model response to these changes was evaluated against data from twenty globally distributed FLUXNET towers, representing a cross-section of biomes that include grassland, cropland, shrubland, evergreen needleleaf forest and deciduous broadleaf forest. Scenarios based on 14 different combinations of model structure and parameterization were ranked based on their mean value of Nash–Sutcliffe Efficiency. Results illustrated considerable variability in model performance both within and between biome types. Indeed, no single model consistently outperformed any other when considered across all biomes. For instance, in grassland and shrubland sites, the single-source Penman–Monteith model performed the best. In croplands it was the three-source Mu model, while for evergreen needleleaf and deciduous broadleaf forests, the Shuttleworth–Wallace model rated highest. Interestingly, these top ranked scenarios all shared the simple lookup-table based surface resistance parameterization of Mu et al. (2011), while a more complex Jarvis multiplicative method for surface resistance produced lower ranked simulations. The highly ranked scenarios mostly employed a version of the Thom (1975) formulation for aerodynamic resistance that incorporated dynamic values of roughness parameters. This was true for all cases except over deciduous broadleaf sites, where the simpler aerodynamic resistance approach of Mu et al. (2011) showed improved performance. Overall, the results illustrate the sensitivity of Penman–Monteith type models to model structure, parameterization choice and biome type. A particular challenge in flux estimation relates to developing robust and broadly applicable model formulations. With many choices available for use, providing guidance on the most appropriate scheme to employ is required to advance approaches for routine global scale flux estimates, undertake hydrometeorological assessments or develop hydrological forecasting tools, among many other applications. In such cases, a multi-model ensemble or biome-specific tiled evaporation product may be an appropriate solution, given the inherent variability in model and parameterization choice that is observed within single product estimates.

Greenness indices from digital cameras predict the timing and seasonal dynamics of canopy-scale photosynthesis.

The proliferation of digital cameras co-located with eddy covariance instrumentation provides new opportunities to better understand the relationship between canopy phenology and the seasonality of canopy photosynthesis. In this paper we analyze the abilities and limitations of canopy color metrics measured by digital repeat photography to track seasonal canopy development and photosynthesis, determine phenological transition dates, and estimate intra-annual and interannual variability in canopy photosynthesis. We used 59 site-years of camera imagery and net ecosystem exchange measurements from 17 towers spanning three plant functional types (deciduous broadleaf forest, evergreen needleleaf forest, and grassland/crops) to derive color indices and estimate gross primary productivity (GPP). GPP was strongly correlated with greenness derived from camera imagery in all three plant functional types. Specifically, the beginning of the photosynthetic period in deciduous broadleaf forest and grassland/crops and the end of the photosynthetic period in grassland/crops were both correlated with changes in greenness; changes in redness were correlated with the end of the photosynthetic period in deciduous broadleaf forest. However, it was not possible to accurately identify the beginning or ending of the photosynthetic period using camera greenness in evergreen needleleaf forest. At deciduous broadleaf sites, anomalies in integrated greenness and total GPP were significantly correlated up to 60 days after the mean onset date for the start of spring. More generally, results from this work demonstrate that digital repeat photography can be used to quantify both the duration of the photosynthetically active period as well as total GPP in deciduous broadleaf forest and grassland/crops, but that new and different approaches are required before comparable results can be achieved in evergreen needleleaf forest.

Evaluation of continental carbon cycle simulations with North American flux tower observations

Terrestrial biosphere models can help identify physical processes that control carbon dynamics, including land–atmosphere CO2 fluxes, and have great potential to predict the terrestrial ecosystem response to changing climate. The skill of models that provide continental‐scale carbon flux estimates, however, remains largely untested. This paper evaluates the performance of continental‐scale flux estimates from 17 models against observations from 36 North American flux towers. Fluxes extracted from regional model simulations were compared with co‐located flux tower observations at monthly and annual time increments. Site‐level model simulations were used to help interpret sources of the mismatch between the regional simulations and site‐based observations. On average, the regional model runs overestimated the annual gross primary productivity (5%) and total respiration (15%), and they significantly underestimated the annual net carbon uptake (64%) during the time period 2000–2005. Comparison with site‐level simulations implicated choices specific to regional model simulations as contributors to the gross flux biases, but not the net carbon uptake bias. The models performed the best at simulating carbon exchange at deciduous broadleaf sites, likely because a number of models used prescribed phenology to simulate seasonal fluxes. The models did not perform as well for crop, grass, and evergreen sites. The regional models matched the observations most closely in terms of seasonal correlation and seasonal magnitude of variation, but they have very little skill at interannual correlation and minimal skill at interannual magnitude of variability. The comparison of site vs. regional‐level model runs demonstrated that (1) the interannual correlation is higher for site‐level model runs, but the skill remains low; and (2) the underestimation of year‐to‐year variability for all fluxes is an inherent weakness of the models. The best‐performing regional models that did not use flux tower calibration were CLM‐CN, CASA‐GFEDv2, and SIB3.1. Two flux tower calibrated, empirical models, EC‐MOD and MOD17+, performed as well as the best process‐based models. This suggests that (1) empirical, calibrated models can perform as well as complex, process‐based models and (2) combining process‐based model structure with relevant constraining data could significantly improve model performance.

Forest water use and water use efficiency at elevated CO2: a model‐data intercomparison at two contrasting temperate forest FACE sites

Predicted responses of transpiration to elevated atmospheric CO2 concentration (eCO2 ) are highly variable amongst process-based models. To better understand and constrain this variability amongst models, we conducted an intercomparison of 11 ecosystem models applied to data from two forest free-air CO2 enrichment (FACE) experiments at Duke University and Oak Ridge National Laboratory. We analysed model structures to identify the key underlying assumptions causing differences in model predictions of transpiration and canopy water use efficiency. We then compared the models against data to identify model assumptions that are incorrect or are large sources of uncertainty. We found that model-to-model and model-to-observations differences resulted from four key sets of assumptions, namely (i) the nature of the stomatal response to elevated CO2 (coupling between photosynthesis and stomata was supported by the data); (ii) the roles of the leaf and atmospheric boundary layer (models which assumed multiple conductance terms in series predicted more decoupled fluxes than observed at the broadleaf site); (iii) the treatment of canopy interception (large intermodel variability, 2-15%); and (iv) the impact of soil moisture stress (process uncertainty in how models limit carbon and water fluxes during moisture stress). Overall, model predictions of the CO2 effect on WUE were reasonable (intermodel μ=approximately 28%±10%) compared to the observations (μ=approximately 30%±13%) at the well-coupled coniferous site (Duke), but poor (intermodel μ=approximately 24%±6%; observations μ=approximately 38%±7%) at the broadleaf site (Oak Ridge). The study yields a framework for analysing and interpreting model predictions of transpiration responses to eCO2 , and highlights key improvements to these types of models.

Mercury concentrations in tropical resident and migrant songbirds on Hispaniola

Despite growing concerns over mercury (Hg) exposure to humans and wildlife on a global scale, little is known about Hg bioaccumulation in the New World tropics. From 2005 to 2011, we monitored Hg concentrations in blood of nine avian species occupying a geographic range of tropical wet broadleaf sites on the island of Hispaniola, including eight passerines (two Nearctic-Neotropical migrant and six resident species) and one top order predatory accipiter. Invertivorous songbirds were further differentiated by foraging guild, with six species of ground-foragers and two species of foliage-gleaners. Blood Hg concentrations were orders of magnitude higher in birds sampled in central and southern cloud forest sites (1,000-1,800 m elevation) than in northern and northeastern rainforest sites (50-500 m elevation), with migratory and resident species both showing 2-20× greater blood Hg concentrations in cloud forests than in rainforests. Within cloud forest sites, ground-foraging species had higher Hg concentrations than foliage-gleaning species. Top order predatory sharp-shinned hawks (Accipiter striatus) had the highest blood Hg concentrations among all species, suggesting that Hg biomagnification is occurring in terrestrial forests of Hispaniola. Two migrant songbird species overwintering on the island had higher blood Hg concentrations than have been recorded on their North American breeding grounds. Future studies should seek to elucidate sources of variation in atmospheric Hg deposition on Hispaniola and to quantify the dynamics of Hg cycling in tropical forest ecosystems, which may differ in important ways from patterns documented in temperate forest ecosystems.

Alien species and interspecific competition: effects of introduced eastern grey squirrels on red squirrel population dynamics

Summary Throughout much of Britain, Ireland and north Italy, red squirrels (Sciurus vulgaris L.) have been replaced by alien grey squirrels (S. carolinensis Gmelin) introduced from North America. We have studied squirrels in two mixed woodlands in north Italy and two conifer forests in north England. In each country, one site was occupied by red squirrels and one site by both species. We have previously considered interference competition and exploitation competition for food and space between red and grey squirrels and have showed that grey squirrels caused reduced body growth in juvenile and subadult red squirrels, and compete for tree seeds cached by adult red squirrels in spring. Here we report on the effects of grey squirrels on three fitness components in red squirrels that have consequence at the population level: fecundity, residency and recruitment. Litter production peaked in the spring and summer, but fewer females bred in the summer with grey squirrels present. In addition, fewer individual red squirrel females produced two litters per year in the sites with grey squirrels. Moreover, red squirrel recruitment rate and, in the mixed broadleaf sites, red squirrel juvenile residency, decreased with increasing grey squirrel density. Fecundity of individual female red squirrels was lower in red–grey than in red‐only sites because they had a lower body mass in sites with grey squirrels. Overall, there was no significant effect of grey squirrels on residency of adult red squirrels or on population turnover rate. However, the presence of grey squirrels resulted in a reduction in red squirrel fitness which was evident by lower population summer breeding and a lower recruitment. Over time, this will result in a decline in population size and eventually population extinction.

Ground flora and associated arthropod communities of forest road edges in Connemara, Ireland

Forest road edges in a conifer plantation in Connemara, Ireland weresampled for ground flora and associated terrestrial invertebrates along thenorthern edge of a forest road bordered by conifers (Conifer 1 site),broadleaves (Broadleaf site) and a clearfelled area (Open site). In addition,the southern edges of the road bordered by a clearing (Scallop site) and of anadjacent forest road bordered by conifers (Conifer 2 site) were sampled. Medianground plant species richness per quadrat was lower at the Conifer sites than atthe other sites. A positive relationship between plant species richness andlight levels was apparent. Median arthropod morphospecies richness per sweep wassignificantly greater (P < 0.01) at the Broadleaf site(39.0) than at the Conifer 2 site (25.5). Median morphospecies richness forHemiptera was significantly greater at the Open (7.0) and Broadleaf (6.5) sitesthan at the Conifer 1 site (2.0, P < 0.001) and Conifer2 site (2.0, P < 0.01). For Diptera, medianmorphospecies richness was significantly greater at the Open site (13.5) than atthe Conifer 1 site (6.0, P < 0.01), Conifer 2 site (6.0,P < 0.001) and Scallop site (8.0, P< 0.05). There was a positive relationship between plant species richness andarthropod morphospecies richness with stronger species richness relationshipsevident between plants and Diptera and between plants and Hemiptera,respectively. The results of this study suggest that open spaces and broadleafplantings in this commercial conifer plantation in the west of Ireland could beimportant for biodiversity.