Vegetation Surface Area Research Articles

Preliminary Experimental Laboratory Methods to Analyse the Insulation Capacity of Vertical Greening on Temperature and Relative Humidity

Ground-based vertical greening is one of the well-known nature-based solutions that is widely used in city centres due to its small footprint and the large surface area of vegetation. Although the impact of vertical greening on the local microclimate has already been extensively researched, there is a poor understanding of the impact of vertical greening on historic building fabrics. The impact of vertical greening on microclimate environments has primarily been researched through in situ case-study monitoring; as such, there are currently no standard protocols for investigating this impact in laboratory studies. By performing simulations in controlled laboratory conditions, the influence of vertical greening on specific environmental conditions can be assessed as well as the significance for key mechanisms, such as the insulation capacity of a vegetation layer. Experimental results on the insulation capacity of vertical greening illustrate that the presence of vertical greening reduces the rate of heat exchange between the wall and the surrounding environment compared to the bare wall, resulting in a delayed temperature response of the wall. This delay varies across the seasons or its intensity, which is represented, for instance, by a more pronounced delay in the wall’s surface temperature response in summer than in winter. However, the magnitude of the insulation capacity is more pronounced in winter (up to +2.1 °C) compared to summertime. The insulation capacity of vertical greening is more likely to have a significant impact on façades with a lack of solar irradiation, such as façades facing north or shaded by built surroundings. This experimental investigation can help build an understanding of these processes more fundamentally and support the interpretation of in situ case-study monitoring as well as provide a standardized approach to investigate the environmental performance of vertical greening across climatic regions and seasons.

Forest regeneration pathways in contrasting deforestation patterns of Amazonia

Secondary vegetation is increasingly recognized as a key element for biodiversity conservation and carbon stocks in human-modified landscapes. Contrasting deforestation patterns should lead to distinct patterns of forest regeneration, but this relationship is yet to be unveiled for long-term studies. Using Landsat data from 1985–2015, we analyzed the surface area, spatial distribution, and age of secondary vegetation in Fishbone and Geometric patterns of deforestation. Additionally, we investigated to which extent secondary vegetation reduces forest patch isolation at the landscape level across time. We found the Fishbone pattern to consistently have more secondary vegetation over time than the Geometric pattern, despite having the same size of the deforested area. However, the Fishbone pattern showed more secondary vegetation area with less than 5 years old, while the Geometric pattern showed more area with secondary vegetation with more than 30 years old. Regarding spatial distribution, we found secondary vegetation to be more spread across the entire landscape at the Fishbone pattern and to consistently reduce forest patch isolation across time. This is congruent with the land use typically found in Geometric (industrial cropping and ranching) and Fishbone (fallow agriculture with small-scale ranching) patterns. These findings indicate that the Fishbone pattern of deforestation produces a more biodiversity-friendly landscape structure than the Geometric pattern. On the other hand, older secondary vegetation found in the Geometric deforestation pattern could indicate more carbon stocked in those landscapes. Future public policies of land use and occupation should consider better landscape planning and management to overcome this duality and create synergies between biodiversity conservation and secondary vegetation carbon stock.

Effect Of Spraying Humic Acid And Salicylic Acid On Potato Leaf Area, Yield And Quality At Two Different Levels Of Field Capacity

Abstract: This study was carried out at Al-Hanadi Research Station -Agricultural Scientific Research Center in Lattakia during 2019-2020, to study the effect of foliar spray with different concentrations of humic acid (500, 1000 and 1500 ppm) and salicylic acid (50, 100 and 150 ppm) on Spunta potato plants at two levels of irrigation 40% and 80% of field capacity. The experiment included 14 treatments and 3 replicates for each one. It was designed with a complete randomization system. Results showed a decrease in vegetative surface area and yield kg/m2 at irrigation level 40% of field capacity, while tubers content of proline and dry matter tubers increased. The highest tuber content of proline was in humic acid 1000 ppm at 40% of field capacity. At irrigation level 80% of field capacity, the treatment with salicylic acid 100 ppm showed the highest yield 4.09 kg/m2and the highest tuber content of sugars in salicylic acid 100 ppm at the same irrigation level. Salicylic acid treatment 50 ppm gave also the highest vegetative surface area (2278) cm2.

A methodological approach for the assessment of basic crown parameters in Scots pine stands

Among other measurement techniques applied for the assessment of leaf area index, direct methods are still valued as the most accurate measures and often implemented as calibration tools. Even though more attention has been given to indirect measurements of tree crown properties in forest ecosystems over the last decades, the present study was designed to discuss the direct (destructive) and indirect (non-destructive) methods used for the assessment of crown measures in the stands defoliated from 20 to 90%. The stands with similar stand characteristics and representing relatively wide range of defoliation served as an appropriate target for the assessment of foliage mass variations.
 Overall, this study showed that the foliage mass or its surface area and defoliation at the stand level can be determined by the conventional methods used for the assessment of defoliation in forest monitoring programme as well as the PAR transmission methods. The findings showed that needle surface area decreased with the increase of tree defoliation; however, the changes of branch and stem surface areas were insignificant. Otherwise, the branch and shoot area contribute significantly to the total vegetation surface area at least in Scots pine stands. This study also strengthened the idea that the indirect measurement of vegetation area index underestimated vegetation area index at least in Scots pine stands defoliated less than 60%. The multivariate regression models were developed using tree diameter at breast height and tree crown defoliation ranges to estimate needle surface area. Keywords: Pinus sylvestris, crown defoliation, needle area index, regression model

Local contributions to beta diversity in urban pond networks: Implications for biodiversity conservation and management

AbstractAimAn understanding of how biotic communities are spatially organized is necessary to identify and prioritize habitats within landscape‐scale biodiversity conservation. Local contribution to beta diversity (LCBD) identifies individual habitats that make a significant contribution to beta diversity and may have important practical implications, particularly for conservation of habitat networks. In this study, we develop and apply a conservation prioritization approach based on LCBD in aquatic invertebrate communities from 132 ponds.LocationFive urban settlements in the UK: Halton, Loughborough, Stockport, Birmingham and Huddersfield.MethodsWe partition LCBD into richness difference (nestedness:RichDiffLCBD) and species replacement (turnover:ReplLCBD) and identify key environmental variables driving LCBD. We examine LCBD at two scales relevant to conservation planning: within urban settlements and nationally across the UK.ResultsSignificant differences in LCBD values were recorded among the five settlements. In four of the five urban settlements studied, pond sites with the greatest LCBD values typically showed high replacement values. Significant LCBD sites and sites with high taxonomic diversity together supported more of the regional species pool (70%–97%) than sites with high taxonomic diversity alone (54%–94%) or what could be protected by the random selection of sites. LCBD was significantly associated with vegetation shading, surface area, altitude and macrophyte cover.Main conclusionsConservation prioritization that incorporates LCBD and sites with high taxonomic diversity improves the effectiveness of conservation actions within pond habitat networks, ensures sites supporting high biodiversity are protected and provides a method to define a spatial network of protected sites. Identifying new, effective conservation approaches, particularly in urban areas where resources may be scarce and conflicts regarding land use exist, is essential to ensure biodiversity is fully supported, and detrimental anthropogenic effects are reduced.

Spatiotemporal Patterns of Land Surface Temperature Change in the Tibetan Plateau Based on MODIS/Terra Daily Product From 2000 to 2018

Under the background of climate change, the Tibetan Plateau presents high spatial and temporal variability in land surface temperature (LST). To understand the spatiotemporal patterns of LST change, this article conducted a spatiotemporal analysis using the Mann-Kendall trend analysis method with time series of mean annual surface temperature extracted from the moderate resolution imaging spectroradiometer/Terra daily LST product from 2000 to 2018. The analysis indicated that both daytime and nighttime MASTs show an obvious warming trend with the average rates of 0.028 K/year and 0.069 K/year, and the nighttime variation has larger spatial coverage. Areas ranging from 4500 to 5000 m exhibited the strongest warming effect. The geodetector method was applied to detect the impacts from seven factors, including elevation, land cover type, latitude, normalized difference vegetation index (NDVI), precipitation, air temperature, and solar radiation on the spatial distribution of LST. The controlling effects of these factors were generally stronger in the nighttime than those in the daytime, and elevation was the most important factor with the contribution scores of 27.12% and 62.98% in the daytime and nighttime, respectively. In addition, the analysis revealed that the temporal changes of LST were mainly caused by surface properties (vegetation, snow cover, and water surface area) changes, radiant flux changes induced by cloud amount changes, and climate warming. In general, this article provides important insights into the spatiotemporal dynamics of LST in the TP since 2000 and helps to reveal the impact of climate change on ecoenvironmental conservation.

Relationships between vegetation cover (Schoenoplectus decipiens) and wetland macroinvertebrate assemblages in a semi-arid landscape (Eastern Cape Karoo, South Africa)

This study investigated macroinvertebrate assemblage composition in relation to the cover of aquatic macrophytes (Schoenoplectus decipiens) for a set of 13 temporary depressional wetlands occurring within a semi-arid environment (Eastern Cape Karoo, South Africa). We hypothesised that invertebrate abundance and taxonomic richness would be higher in wetlands containing aquatic macrophytes than in those lacking them. It was expected that a positive relationship between vegetation cover categories (sparse, moderate and extensive) and invertebrate richness and abundance would be observed. In contrast to expectations, the macroinvertebrate assemblage was not significantly different across the three investigated categories. Non-parametric permutational MANOVA results indicated that the presence/absence of vegetation and wetland surface area had a significant effect on macroinvertebrate assemblage composition. Multivariate regressions (distance-based redundancy analysis) indicated that surface area, dissolved inorganic nitrogen and pelagic chlorophyll a concentration explained significant variation in macroinvertebrate assemblage composition in these wetlands. Overall, the presence or absence of vegetation appears to play a role in structuring the macroinvertebrate assemblages, but no convincing evidence was found for an effect of the vegetation cover gradient (sparse vs moderate vs extensive) on macroinvertebrate assemblages in these temporary wetlands.

Diving duck census efficiency based on monitoring of individually marked females: the influence of breeding stage and timing of census

ABSTRACTCapsule: Observations of individually marked females of three diving duck species showed that the stage of breeding season and census month most affected their resighting probability in the breeding season.Aims: To evaluate the efficiency of a diving duck census in the breeding season based on an analysis of the resighting probability of individually marked female ducks.Methods: We used monitoring data from 2004 to 2015 of individually marked females of Common Pochard Aythya ferina, Tufted Duck Aythya fuligula and Red-crested Pochard Netta rufina in South Bohemia, Czech Republic. Using a model selection approach, the resighting probabilities of females were modelled incorporating covariate parameters, such as stage of breeding, census month, year, numbers of counted individuals, individual species, water surface area and proportion of emergent vegetation.Results: We demonstrated the significant effect of the stage of breeding, year and census month on the resighting probability of females, while the number of individuals, water surface area and proportion of emergent vegetation did not contribute to the best models. Moreover, the three investigated species with different local population sizes did not differ in resighting probabilities. The incubation period of the females (i.e. June) corresponded to the lowest detection probability in the study area.Conclusions: Our approach of using individually marked females contributed to modelling to show census accuracy for diving ducks was substantially enhanced by avoiding counting females during the incubation period. Ultimately, these findings are crucial to increase the accuracy of their breeding population size estimation.

The functional response and resilience in small waterbodies along land-use and environmental gradients.

There is growing recognition of the essential services provided to humanity by functionally intact ecosystems. Freshwater ecosystems are found throughout agricultural and urban landscapes and provide a wide range of ecosystem services, but globally they are also amongst the most vulnerable. In particular, ponds (lentic waters typically less than 2ha), provide natural flood management, sequester carbon and hold significant cultural value. However, to inform their management it is important to understand (1) how functional diversity varies in response to disturbance and (2) the link between biodiversity conservation and ecosystem function. In this study, a meta-analysis of seven separate pond studies from across England and Wales was carried out to explore the effect of urban and agricultural land-use gradients, shading, emergent vegetation, surface area and pH upon groups of functionally similar members of the macroinvertebrate fauna. Functional effect groups were first identified by carrying out a hierarchical cluster analysis using body size, voltinism and feeding habits (18 categories) that are closely related to biogeochemical processes (e.g. nutrient and carbon recycling). Secondly, the influence of the gradients upon effect group membership (functional redundancy-FR) and the breadth of traits available to aid ecosystem recovery (response diversity) was assessed using species counts and functional dispersion (FDis) using 12 response traits. The effect of land-use gradients was unpredictable, whilst there was a negative response in both FR and FDis to shading and positive responses to increases in emergent vegetation cover and surface area. An inconsistent association between FDis and FR suggested that arguments for taxonomic biodiversity conservation to augment ecosystem functioning are too simplistic. Thus, a deeper understanding of the response of functional diversity to disturbance could have greater impact with decision-makers who may relate better to the loss of ecosystem function in response to environmental degradation than species loss alone.

Scenarios of habitat management options to reduce predator impacts on nesting waders

Summary Wetland ecosystems throughout the world are threatened by drainage and intensification of agriculture. Consequently, many wetland species of conservation concern are now restricted to fewer and smaller sites, and maintaining these species often requires intensive habitat management. In Western Europe, breeding wader populations have declined severely as a result of wetland degradation, but very high levels of predation on eggs and chicks are now preventing population recovery. Wet grassland management for breeding waders has focussed on providing suitable nesting habitats, but the potential for management of landscape features to influence predation rates remains largely unknown. Using a 7‐year study of breeding lapwing Vanellus vanellus and redshank Tringa totanus we first identify features that influence nest predation, and then use this information to compare the magnitude of change in nest predation rates that could potentially result from future landscape management scenarios. As lapwing nest predation rates are higher (i) in fields further from patches of tall vegetation, (ii) close (<50 m) to field edges in wet fields, (iii) further from field edges in dry fields and (iv) in areas of low lapwing nesting density, we modelled a series of realistic scenarios in which the area of tall vegetation and the extent and distribution of surface water were varied across the reserve, to quantify the magnitude of change in nest predation rate that could potentially have been achieved through management. Modelled scenarios of changes in surface water and area of tall vegetation indicated that reduced surface flooding combined with removal of tall vegetation could result in significant increases in lapwing nest predation rates in areas with low nesting densities and nests in field centres. By contrast, a ~20% reduction in nest predation, corresponding to ~100 more chicks hatching per year, is predicted in scenarios with expansion of tall vegetation in areas with high lapwing nest density and nests close to field edges. Synthesis and applications. These management scenarios suggest that, for breeding waders in wet grassland landscapes, creating areas of tall vegetation and concentrating surface flooding (to encourage high nesting densities and influence nesting distribution) can potentially help to reduce the unsustainably high levels of nest predation that are preventing population recovery.

Effects of aphid infestation on the biogeochemistry of the water routed through European beech (Fagus sylvatica L.) saplings

Mass outbreaks of herbivore insects perturb the functional properties of forests, by substantially altering water and nutrient cycling of infested trees. Less clear is how low to moderate herbivory affects the vertical flow of nutrients from trees to the soil. We report on the effects of low to moderate infestation levels of the woolly beech aphid (Phyllaphis fagi L.) on the nutrient dynamics and hydrology of European beech (Fagus sylvatica L.). We traced the vertical dynamics of macro and micronutrients via throughfall (TF), stemflow (SF) and Oa litter leachates from potted saplings underneath infested and uninfested control trees. The low infestation levels were insufficient to significantly alter TF and litter leachate composition, although, on average, the release of K and DOC and the immobilization of N (NH4–N) in TF solution were more pronounced under aphid infestation. SF chemistry was significantly altered by aphid activity exhibiting intensified fluxes of K (+159 %), Mg (+82 %), Mn (+93 %), S (+86 %), SO4–S (+62 %), DOS (+137 %), DOC (+51 %) and DON (+62 %), compared to control trees. SF is likely enriched by low and mid-level aphid activity due to its increased residence time in the canopy. It has interaction with large areas of aboveground vegetative surface area representing a cumulative flux of solutes and particulates from both foliar and woody surfaces from above-lying portions of the canopy. Accordingly, SF might be a useful indicator to evaluate the impact of sap- and leaf-feeding herbivores on forest ecosystems.

Multi-dimensional histogram-based information capacity analysis of urban heat island effect using Landsat 8 data

ABSTRACTThe vegetation and impervious surface area (ISA) are the most key indicators for the urban heat islands (UHI). This study used the normalized difference vegetation index (NDVI) as the indicator of vegetation abundance, the modified normalized difference impervious surface index (MNDISI) as the indicator of impervious surface fraction to estimate the land surface temperature (LST)–vegetation relationship and LST–ISA relationship. The land surface cover types were obtained by classification and regression tree (CART). Results demonstrate and verify that LST possessed strong negative correlations with NDVI and positive correlations with MNDISI at various spatial resolutions (30–960 m). Both correlation coefficients reached their strongest points at 30 m resolution, which is believed to be the operational scale of LST, NDVI and MNDISI. Further, information capacity (IC), as a spatial index, is used to characterize the spatial pattern of UHI. Results show that the IC of LST (LSTIC) possessed strong positive correlations with the IC of NDVI (NDVIIC) and the IC of MNDISI (MNDISIIC). It is suggested that the spatial pattern of UHI has a direct correspondence with the vegetation and ISA.

Linking environmental drivers with amphibian species diversity in ponds from subtropical grasslands.

Amphibian distribution patterns are known to be influenced by habitat diversity at breeding sites. Thus, breeding sites variability and how such variability influences anuran diversity is important. Here, we examine which characteristics at breeding sites are most influential on anuran diversity in grasslands associated with Araucaria forest, southern Brazil, especially in places at risk due to anthropic activities. We evaluate the associations between habitat heterogeneity and anuran species diversity in nine body of water from September 2008 to March 2010, in 12 field campaigns in which 16 species of anurans were found. Of the seven habitat descriptors we examined, water depth, pond surface area and distance to the nearest forest fragment explained 81% of total species diversity. Water depth, margin vegetation type, surface area and distance to the next body of water explained between 31-74% of the variance in abundance of nine of the 16 species. Thus, maintenance of body of water, of the vegetation along the water edge and natural forest fragments in the grasslands, along with fire control (used to renovation of pasture), are fundamentally important for the maintenance of anuran species diversity through the conservation of their breeding sites.

Long-term decline in a salt marsh hare population largely driven by bottom-up factors

The widespread decline of the European brown hare (Lepus europaeus) in Europe has been attributed to both bottom-up and top-down factors, as well as climate change. Few studies have attempted to study the relative importance of these factors considered simultaneously. In this study we tested the hypotheses that hare population density is regulated by bottom-up (food), top-down (predation) or abiotic factors including tidal floods and climatic conditions. We related data on hare population density on a relatively isolated island to changes in surface area of suitable vs. unsuitable vegetation for forage, predator densities, flooding parameters and climatic variables. During the study period (1996–2012), hare numbers decreased from 580 to 219. Estimated population density was positively correlated with the cover of short, intermediate successional vegetation types and was negatively correlated with the cover of tall, late successional vegetation types. These findings corroborate results from earlier experimental studies that reported a strong aversion of hares to tall vegetation. Additionally, we found indications that raptor population density and unusually high floods also exerted negative effects on hare population density. We conclude that bottom-up factors (the availability of suitable forage) are the main regulators of the studied hare population. This suggests that the importance of bottom-up effects has been underestimated and could explain leporid population decline in areas that have experienced a similar increase in tall, unsuitable vegetation.

Removal of Vegetative Clippings Reduces Dissolved Phosphorus Loss in Runoff

Rainfall simulation was used to study the vegetative filter strip (VFS) conditions under which losses of total dissolved phosphorus (TDP) and dissolved reactive phosphorus (DRP) leaching occur. Boxes containing silt loam soil were planted with ryegrass and cut at two different intervals prior to simulated rainfall 14 days apart. Grass clippings were either removed or retained. During the second simulated rainfall, runoff TDP and DRP were greater for treatments cut the day before irrigation with clippings retained as compared to treatments cut the same day as irrigation with clippings retained. Removing clippings yielded the lowest mean TDP and DRP concentrations. Increasing the senesced vegetative surface area for contact with water, and the amount of time for leaching to occur, resulted in the greatest DRP loss. The VFS management implications should consider clipping removal or no or reduced mowing during the growing season followed by end-of-season removal to reduce DRP leaching losses.

Three-dimensional (3D) structure model and its parameters for poplar shelterbelts

The spatial functions of surface area density (vegetative surface area per unit canopy volume) and cubic density (vegetative volume per unit canopy volume) have been used as two three-dimensional (3D) structural descriptors for shelterbelt. The functions were defined by models as a general case. However, sub-models such as surface area, volume, and corresponding distributions were not explicitly defined for poplar trees, which are a dominant woody species in shelterbelts all over China, and this limits applications of the models in China and elsewhere. In order to define and develop these sub-models for shelterbelts, poplar trees were destructively sampled from multiple-row shelterbelts and then were measured for their surface area and volume. Using these measurements, we estimated parameters to define their equations explicitly. Based on the architecture and planting patterns of trees in shelterbelts, the distribution of the surface areas and volumes vertically and across the width for different tree heights were constructed for the three components of trunks, branches and leaves. Incorporating the defined equations into the models, we described the 3D structure of a multiple-row poplar shelterbelt. The results showed that, the spatial change in magnitude of surface area density (0.215–10.131 m2/m3) or cubic density (0.00007–0.04667 m3/m3) in shelterbelts is large and their distributions are not uniform. The assumption for boundary-layer flow modeling efforts that the 3D distribution of shelterbelt structure was uniform is not the case in field. The 3D structure model not only can be used to model the flow field as influenced by each tree component, but also can express the entire aerodynamic characteristics of a shelterbelt. The methodologies and equations that are developed in this study can be applied to estimate the 3D structure of a shelterbelt with a design similar to our studied poplar shelterbelts in terms of species composition and planting patterns. The fitted models can be used to describe the 3D aerodynamic structure of field shelterbelts. Furthermore, an improved description of shelterbelt structure has great potential to improve the simulation of boundary layer flows as influenced by that shelterbelt. Such insights can eventually be used to quantify the design of shelterbelt structure and/or adjustment for managing the function of shelterbelts and their effects on microclimate.

Estimates of population size of white‐chinned petrels and grey petrels at Kerguelen Islands and sensitivity to fisheries

AbstractWhite‐chinned petrels Procellaria aequinoctialis and grey petrels Procellaria cinerea are among the most frequently killed seabird species by accidental bycatch, and both species have received strong conservation concern. Data on population size are required to evaluate the impact of bycatch and to establish management plans. We estimated the population size of both species at Kerguelen, Southern Indian Ocean, from 2004 to 2006 by explicitly taking into account detection probability of burrows using distance sampling and burrow occupancy. A total of 31 line‐transects were distributed across the eastern part of Kerguelen, representing a total length of 566 km. Detectability was low (from 0.19 to 0.54 for white‐chinned petrels, 0.58 for grey petrels). Burrow densities varied from 1.37±0.67 to 25.77±5.23 burrows ha−1 for white‐chinned petrels and was 2.78±0.79 burrows ha−1 for grey petrels. For white‐chinned petrels, these densities were extrapolated to the entire surface area of vegetation and there were 234 000 (186 000–297 000) active burrows on Kerguelen. For grey petrels, the number of active burrows for the eastern part of Kerguelen was 3400 (1900–5600). Based on these estimates, the potential biological removal method suggests that the additional mortality on birds caused by the fisheries operating around Kerguelen can be considered a serious threat for the species at least at the regional scale of the Southern Indian Ocean, especially for grey petrels.

Overcoming the Obstacles of Operating a Biochemical Reactor and Aerobic Polishing Cell Year Round in Central Montana

A demonstration-scale passive treatment system (PTS) including a biochemical reactor (BCR) and an aerobic polishing cell (APC) has been constructed at a historic gold mine in Central Montana. This site provided the challenge of being located where the frost depth is over four feet and temperatures dropped to negative 40 F in the winter of 2007-2008. The demonstration-scale PTS, including the APC, was operated through the winter. This paper presents the results of the testing as well as the special consideration and precautions taken to ensure the PTS could function properly year round. The BCR uses a mixture of organic components including wood chips, sawdust, hay, limestone, manure, and crushed basalt to remove constituents of concern (COC), including thallium, selenium, zinc, and nitrate from the mining influenced water (MIW) at the site. As the MIW passes through the BCR, a suite of biological and chemical reactions (biological reduction, metal sulfide precipitation, metal hydroxide precipitation, adsorption, etc.) combine to reduce the COC concentrations in the effluent. Over the first 14 months of BCR operation thallium was removed at >99%, selenium was removed at >99% until BCR maintenance disturbed the substrate in the fall of 2008, and zinc and nitrate were removed to non detect levels throughout. The BCR has operated successfully through two winters where temperatures reached levels as low as -40 F for up to weeks at a time. Due to the natural degradation of the organic substrate mixture used in the BCR, the water exiting the cell has elevated levels of organic matter as well as manganese, iron, and arsenic. These constituents are removed in an APC, which is comprised of a series of ponds that contain vegetation and large surface area to promote aeration of the water. As oxygen is introduced to the water, the biochemical oxygen demand, manganese, iron, and arsenic are changed from dissolved to particulate form and either settle or are filtered out by the vegetation in the APC. The APC has yet to operate through a full winter without retrofits and upgrades. Additional

A tractor-mounted scanning LIDAR for the non-destructive measurement of vegetative volume and surface area of tree-row plantations: A comparison with conventional destructive measurements

The use of a low-cost tractor-mounted scanning Light Detection and Ranging (LIDAR) system for capable of making non-destructive recordings of tree-row structure in orchards and vineyards is described. Field tests consisted of several LIDAR measurements on both sides of the crop row, before and after defoliation of selected trees. Summary parameters describing the tree-row volume and the total crop surface area viewed by the LIDAR (expressed as a ratio with ground surface area) were derived using a suitable numerical algorithm. The results for apple and pear orchards and a wine producing vineyard were shown to be in reasonable agreement with the results derived from a destructive leaf sampling method. Also, good correlation was found between manual and sensor-based measurements of the vegetative volume of tree-row plantations. The Tree Area Index parameter, TAI, gave the best correlation between destructive and non-destructive (i.e. LIDAR-based) determinants of crop leaf area. The LIDAR system proved to be a powerful technique for low cost, prompt and non-destructive estimates of the volume and leaf-area characteristics of plants.

Detectability of Red-Edge-shifted Vegetation on Terrestrial Planets Orbiting M Stars

We have explored the detectability of exovegetation on the surface of a terrestrial planet orbiting an M star. The exovegetation is responsible for producing a pigment-derived surface signature that is redshifted with respect to the Earth vegetation's red edge. The redshift was estimated using a model of leaf optical property spectra (Jacquemoud & Baret) combined with a 3 photon photosynthetic scheme calculated by Wolstencroft & Raven for a possible exovegetation growing on an M star planet. To study the detectability of this surface biosignature on an M star terrestrial planet, we have used the three-dimensional model developed by Tinetti et al. for the case of the Earth. This model can generate disk-averaged spectra and broadband integrated fluxes, which will be useful for future terrestrial planet exploration missions, such as the NASA Terrestrial Planet Finder Coronagraph. Input to this model were the atmospheric profiles and cloud distributions predicted by Joshi and coworkers for a synchronous planet orbiting an M dwarf and the distinctive surface reflectance of the exovegetation. While on Earth this pigment-derived surface feature would be almost completely masked by water absorption, even in a cloud-free atmosphere, we found that the strength of the edge feature on our simulated M star terrestrial planet can exceed that on Earth, given the right conditions. Obviously, the detectability of such biosignatures would be highly dependent on the extent of vegetation surface area, cloud cover, and viewing angle.