Vegetation mapping is often considered the process of identifying landscape patterns of individuals or clusters of species or life forms (LF). At the landscape scale, the larger pattern represented by individuals or clusters represents the conceptualization of "vegetation mapping" and can be used as a building block to describe an ecosystem. To represent these building blocks or LF a "common entity (CE)" concept is introduced to represent the components of Formations as described by the National Vegetation Classification (NVC) system. The NVC has established protocols to consistently represent plant communities and promote coordinated management, particularly across jurisdictional boundaries. However, it is not a universal standard and the methods of producing detailed maps of vegetation CE from very high spatial resolution (VHR) remote sensing data are important research questions.This research addressed how best to understand and represent plant cover in arid regions, the most effective methods of mapping vegetation cover using high spatial resolution data, how to assess the accuracy of these maps, and their value in establishing more standardized mapping protocols across ecosystems. Utilizing VHR products from the IKONOS and QuickBird sensors the study focused on the Coronado National Memorial and Chiricahua National Monument in Arizona and Los Ajos and Pinacate - Grand Desierto Biosphere Reserves in México. Individual CE were semi-automatically mapped incorporating spectral, textural and geostatistical variables. The results were evaluated across sensors, study sites, and input variables. In addition, multiple methods of acquiring field data for accuracy assessment were evaluated and then an evaluation was made of a semi-automatic determination of Formation based on CE.The results of the study suggest consistency across study sites using the IKONOSdata. A comparison between VHR products from the same place is feasible but sensor spectral differences may affect which derived bands would improve classification. CE classification procedures were not significantly different across sensors. The overall accuracy obtained for each Park was 59.5% for Chiricahua using QuickBird and 51.9% using IKONOS; at Pinacate 70.0% using IKONOS, and 55.9% for Ajos. Incorporating the geostatistical semi-variogram variables improved CE accuracy for some CE but not all.

Climate change will affect Arctic plant communities directly, by altering growth and recruitment, and indirectly, by increasing the frequency of natural disturbance. Since the structure of northern vegetation influences global climate, understanding both temperature and disturbance effects on vegetation is critical. Here, I investigate the influence of temperature and disturbance on Low Arctic vegetation at several spatio-temporal scales in the Mackenzie Delta Region, N.W.T. To disentangle the relative impact of temperature and disturbance on forest-tundra and tundra ecosystems, I sampled microenvironmental variability, plant community composition, and green alder abundance, growth, and reproduction on disturbed (burns and thaw slumps) and undisturbed sites across a regional temperature gradient. Disturbed areas showed increases in alder productivity, catkin production, and seed viability, as well as differences in plant community composition and microenvironment. The magnitude of plot-level responses to disturbance compared to variation across the temperature gradient suggests that in the short-term, increasing the frequency of disturbance may exert a stronger influence on tundra ecosystems than changes in temperature. At the plot level, increases in alder seed viability and recruitment at warmer sites point to the fine-scale mechanisms by which shrub abundance will change. To examine the relative influence of temperature and biophysical variables on landscape-level patterns of shrub dominance, I mapped Low Arctic vegetation using aerial photos. At this broader scale, correlations between temperature and the areal extent of shrub tundra suggest that warming will increase the dominance of shrub tundra. To assess the magnitude of changes in temperature and thaw slump activity, I analyzed climate records and mapped retrogressive thaw slumps using aerial photographs. An increase in thaw slump activity in recent decades, coincident with higher temperatures, suggests that continued warming will change the area affected by thermokarst disturbances like slumps. Taken together, my research indicates that the effects climate change will be magnified by shifts in the frequency of disturbance, initiating changes to Arctic vegetation with significant implications for global climate. My work also shows that to fully understand the influence of patch-landscape feedbacks on Arctic vegetation dynamics, the effects of disturbance must be examined across longer temporal and broader spatial scales.

Biržulio ežero apyežeryje inventorizuota 277 induočių augalų rūšys, priklausančios 71 šeimai ir 51 eilei.Gausiausios augalų rūšimis yra Asteraceae (28 rūšys), Poaceae (25 rūšys), Fabaceae (17 rūšių), Ranunculaceae (16 rūšių), Apiaceae (12 rūšių), Lamiaceae (10 rūšių). Kitose šeimose rasta mažiau nei 10 rūšių. Rastos 5 į Lietuvos RK įrašytos rūšys. Orchis mascula (2 kategorija) – rastos 4 augimvietės ŠR dalyje. Malaxis monophylos (2 kategorija) – vienas individas rastas prie Sąsmaukos miške. Iris sibirica (2 kategorija) – rastos 7 augimvietės rytinėje dalyje, netoli Mažojo Biržulio. Betula humilis (2 kategorija) – randamas rytinėje ir ŠV dalyje. Gausiausi jo sąžalynai yra Mažojo Biržulio pakrantėse. Dactylorhiza incarnata (4 kategorija) – rytinėje ežero dalyje rastos 3 augimvietės. Biržulio ežero apyežeryje aprašyta 36 pievų bendrijos. Šios bendrijos priklauso 4 klasėms, 4 eilėms, 7 sąjungoms ir 14 asociacijų. Biržulio ežero apyežerio Iridetum sibirici Philippi 1960 – įtraukta į LRK augalų bendrijas. Tirtoje teritorijoje rastos ir aprašytos 6 miško bendrijos: Carici elongate - Alnetum glutinosae, Betuletum pubescentis, Betulo – Salicetum repentis, Tilio – Qercetum roboris, Ledo – Pinetum, Salicetum pentandro – cinereae. Aprašytos 5 Iridetum sibirici Philippi 1960 bendrijos. Įvertintas šių bendrijų: sąžalyno atsistatymas, gyvybingumas, žydėjimo ir derėjimo gausa bei ligų ir kenkėjų pažeidimai. Gyvybingiausios Iridetum sibirici Philippi 1960 bendrijos Nr. 1 ir 5. / 277 plant species belonging to 71 families and 51 lines were inventoried in the areas of Lake Biržulis. The richest in the plant species are: Asteraceae (28 species), Poaceae (25 species), Fabaceae (17 species), Ranunculaceae (16 species), Apiaceae (12 species), Lamiaceae (10 species). Les than 10 species were found in other families. 5 species that are written into the Red Book of Lithuania were found. 4 habitats of Orchis mascula (category 2) were found in the North East. One example of Malaxis monophylos (category 2) was found at the isthmus in the forest. 7 habitats of Iris sibirica (category 2) were found in the eastern part, not far from Lake Mažasis Biržulis. Betula humilis (category 2) is localized in the eastern part and in the North West. The richest overgrowths are at the strands of Lake Mažasis Biržulis. 3 habitats of Dactylorhiza incarnata (category 4) were identified in the eastern part of the lake. 36 grassland communities were depicted in the areas of Lake Biržulis. These communities belong to 4 classes, 4 lines, 7 unions and 14 aggregations. Iridetum sibirici Philippi 1960, found in areas of Lake Biržulis, is registered into the plant communities of the Red Book of Lithuania. Also 6 forest communities in the examined area were found and described. They are: Carici elongate - Alnetum glutinosae, Betuletum pubescentis, Betulo – Salicetum repentis, Tilio – Qercetum roboris, Ledo – Pinetum, Salicetum pentandro – cinereae. Moreover, 5 Iridetum sibirici... [to full text]

In an effort to better understand the impacts of nitrogen oxides (NOx) emissions from oil sands development on soils and vegetation, a laboratory experiment was designed, which mimicked the natural and reclaimed boreal forest environment found in the Fort McMurray area. The primary objective of this research was to examine the effects of various types and concentrations of NOx under a controlled laboratory study, and to provide recommendations and management strategies with respect to NOx deposition management. Findings indicated that, for some vegetation types, significant relationships exist between NOx treatment and vegetation height, biomass, and percent total nitrogen responses. Furthermore, some soil chemical parameters exhibited significant differences due to treatment and or soil depth, and some appeared to serve as better indicators of NOx deposition. Recommendations are made with respect to future research considerations and management strategies for NOx emissions including consideration of both eutrophication and acidification potential.

Marsh vegetation is widely considered to offer protection against coastal storm damage, and vegetated flow has thus become a key area of hydrodynamic research. This study investigates the utility of simulated Spartina alterniora marsh vegetation as storm protection using an ADV measurement technique, and is the first to apply jet self-similarity analysis to characterize the overall mean and turbulent flow properties of a three-dimensional axisymmetric jet through a vegetated array. The mean axial flow of a horizontal axisymmetric turbulent jet is obstructed by three configurations of staggered arrays of vertical rigid plant stems. The entire experiment is repeated over five sufficiently high jet Reynolds number conditions to ensure normalization and subsequent collapse of data by nozzle velocity so that experimental error is obtained. All self-similarity parameters for the unobstructed free jet correspond to typical published values: the axial decay coefficient B is 5:8 +/- 0:2, the Gaussian spreading coefficient c is 85 +/- 5, and the halfwidth spreading rate eta_(1/2) is 0:093 +/- 0:003. Upon the introduction of vegetation, from partially obstructed to fully obstructed, B falls from 5:1+/- 0:2 to 4:2 +/- 0:2 and finally 3:7 +/-0:1 for the fully obstructed case, indicating that vegetation reduces axial jet velocity. Cross-sectionally averaged momentum for the unobstructed free jet is M=M0 = 1:05 +/- 0:07, confirming conservation of momentum. Failure of conservation of momentum is most pronounced in the fully obstructed scenario – M=M0 = 0:54 +/- 0:05. The introduction of vegetation increases spreading of the impinging jet. The entrainment coefficient alpha for the free jet case is 0.0575; in the fully obstructed case, alpha = 0:0631. Mean advection of mean and turbulent kinetic energy demonstrates an expected reduction in turbulence intensity within the vegetated array. In general, turbulent production decreases as axial depth of vegetation increases, though retains the bimodal profile of the free jet case; the fully vegetated case, however, exhibits clear peaks behind plant stems. Turbulent transport was shown to be unaffected by vegetation and appears to be primarily a function of axial distance from the jet nozzle. An analysis of rate of dissipation revealed that not only does the cumulative effect of upstream wakes overall depress the magnitude of spectral energy density across all wavenumbers but also that plant stems dissipate large anisotropic eddies in centerline streamwise jet flow. This study, thus, indicates that sparse emergent vegetation both reduces axial flow velocity and has a dissipative effect on jet flow. Typically, however, storm surge does not exhibit the lateral spreading demonstrated by an axisymmetric jet; therefore, the results of this study cannot conclusively support the claim that coastal vegetation reduces storm surge axial velocity.

No description available.

Xeric limestone prairies (XLPs) are open, nonforested communities dominatedby native, C4 perennial grasses. In eastern United States, they occur on shallow, rockycalcareous soils in various physiographic provinces from Missouri and Pennsylvaniasouth to Arkansas and Georgia. Floristic, vegetation, and physical environmental datawere collected from 18 XLPs in Kentucky and used in conjunction with data collected inother studies to provide a synthesis for XLP vegetation in eastern United States and acomparison of this vegetation type with limestone cedar glades and deep-soil barrens.XLPs occur on 33 soil series in five orders (Alfisols, Mollisols, Ultisols, Inceptisols, andVertisols) and on limestone, dolomite, and calcareous shale of Cambrian through Tertiarysystems. In Kentucky, XLPs are restricted to the Interior Low Plateaus, where they aremost frequent on the Upper Mississippian Salem Limestone in the KnobstoneEscarpment and Knobs. Three hundred and thirty-five taxa were recorded in the 18 sitessampled in Kentucky, of which 20 (6.0%) are nonnative and 24 (7.2%) state-listed asrare. The majority of the flora is intraneous C3 hemicryptophytes. Thirteen taxa areendemic to XLPs of eastern United States, but none to those in Kentucky. The native, C4perennial grass Schizachyrium scoparium was dominant in 10 of 12 community types inKentucky identified at a scale of 100-m2 and in 21 of 23 studies of XLPs in easternUnited States. The C4 annual grass Sporobolus vaginiflorus had high frequency values inthe majority of sites in Kentucky, where it often was dominant in the most shallow-soilzones. Variability among XLPs in Kentucky and among the floras of XLPs in differentregions is largely attributable to differences in forb species composition. Soil depth is theprimary abiotic source of variability in XLP community types in Kentucky and in manyother regions of eastern United States. Dendrochronological and aerial photographicstudies support the conclusion that the vast majority of XLPs are not primarycommunities. XLPs on the Cambrian Ketona Dolomite in the Ridge and Valley in BibbCounty, Alabama, are perhaps the only sites which represent an edaphic climax.

Leaf phenology refers to the timing of leaf life cycle events and is essential to our understanding of the earth system as it impacts the terrestrial carbon and water cycles and indirectly global climate through changes in surface roughness and albedo. Traditionally, leaf phenology is described as a response to higher temperatures in spring and lower temperatures in autumn for temperate regions. With the advent of carbon ecosystem models however, we need a better representation of seasonal cycles, one that is able to explain phenology in different areas around the globe, including tropical regions, and has the capacity to predict phenology under future climates. We propose a global phenology model based on the hypothesis that phenology is a strategy through which plants reach optimal carbon assimilation. We fit this 14 parameter model to five years of space borne data of leaf area index using a Bayesian fitting algorithm and we use it to simulate leaf seasonal cycles across the globe. We explain the observed increase in leaf area over the Amazon basin during the dry season through an increase in available direct solar radiation. Seasonal cycles in dry tropical areas are explained by the variation in water availability, while phenology at higher latitudes is driven by changes in temperature and daylength. We explore the hypothesis that phenological traits can be explained at the biome (plant functional group) level and we show that some characteristics can only be explained at the species level due to local factors such as water and nutrient availability. We anticipate that our work can be incorporated into larger earth system models and used to predict future phenological patterns.

This research established long-term alpine monitoring in southwestern British Columbia by following the protocol outlined in the Global Observation Research Initiative in Alpine environments (GLORIA). The aim of this international project is to establish a long-term observation network to obtain standardized data on alpine biodiversity, vegetation patterns and temperature on a global scale. Research plots (known as target regions) were established in the Mount Arrowsmith region on Vancouver Island and in the Whistler region. A target region is comprised of four summits that each represent an altitudinal gradient of vegetation patterns characteristic for the respective mountain regions. The GLORIA protocol focuses on capturing changes in: species richness (number of species), species composition (loss or gain of individual species), patterns of vegetation (changes in % cover), soil temperatures of microhabitats, and snow cover. The analysis of data presented in this thesis related environmental characters (area, slope, elevation, aspect and top cover) and species characters to species richness and composition. This research indicates that overall in the Arrowsmith and Whistler target regions, species richness was consistently greater in larger study plots and in plots where the cover of vascular plant species was relatively high. Elevation alone, sometimes seen as an indirect measure of temperature did not seem to play a significant role in predicting species richness. All species inventoried were ‘as expected’. All of these observations made sense ecologically, are in line with current hypotheses, and demonstrate that the summits chosen in the Arrowsmith and Whistler target regions are typical alpine areas and suitable for long-term study. / Graduate

The riparian forests are hotspots of biodiversity and serve important roles in maintainingthe water quality. The study and understanding of this ecosystem is basic to know how theriparian zones respond to the threat and the changes produced by the urbanization. Theobjective of this pilot study was to know the species richness and check the status of theriparian vegetation along two different rivers in Halmstad, Nissan and Fylleån. The studywas focus on the status of trees at both rivers to see if the proximity of the city has anyimpact on the biodiversity. In total 9 different species were found, nevertheless only 3 ofthese species were founded on both localizations: Quercus robur, Betula pendula and Pinussylvestris. The Shannon Index showed a higher biodiversity on Nissan riparian zones, whichis the river that present the urban component. The urban area is the one that presentshigher level of biodiversity, tree species and number of individuals but there are notenough to be in a good standard. The result just show that the urban area is in a bettercondition that the natural one. The institutional efforts should be focusing on preserveboth environments with special attention to the natural environment.