scholarly journals Vegetation-environment relationships of boreal spruce forests in ten monitoring reference areas in Norway

Sommerfeltia ◽  
1996 ◽  
Vol 22 (1) ◽  
pp. 1-355
Author(s):  
T. Økland
Keyword(s):  
Soil Moisture ◽  
Environmental Conditions ◽  
Species Abundance ◽  
Reference Area ◽  
Data Set ◽  
Spruce Forests ◽  
Dca Ordination ◽  
Total Data ◽  
Species Responses ◽  
Reference Areas

Abstract Vegetational and environmental monitoring of boreal spruce forest was initiated in 1988, as a part of the programme “Contrywide Monitoring of Forest Health” at the Norwegian Institute of Land Inventory (NIJOS). As a basis for monitoring, relationships between trees, understory vegetation and environmental conditions (vertical relationships) were analysed for each of ten reference areas. The reference areas were selected to span regional gradients, in climatic conditions and deposition of airborne pollutants, in old-growth, so-called “bilberry-dominated”, “small-fem” and “low-herb”, also paludified, spruce forests south of the Polar Circle. Fifty 1-m2 meso sample plots, randomly chosen within ten 50-m2 macro sample plots in each reference area, were subjected to vegetation analysis, using frequency in subplots as species abundance measure. Environmental (including soil chemical) and tree parameters were recorded for meso as well as macro sample plots. The main vegetational gradients were found by parallel use of DCA and LNMDS ordination methods and subjected to environmental interpretation, mainly by means of non-parametric correlation analyses. DCA and LNMDS in most cases revealed the same main gradients in vegetation, but outliers were more frequent in LNMDS ordinations, due to higher vulnerability of this method to plots with deviating number of species. A complex-gradient in nutrient conditions, with pH and the concentration of nitrogen as the most constantly contributing variables, but with considerable between-area variation with respect to important cations, was evident in nine reference areas. Soil moisture varied along the second vegetational gradient in most areas. In the three most humid reference areas, the Ca concentration was related to variation in soil moisture and gradients from below to between trees, while unrelated or inversely related to the same vegetational gradient as pH. Species abundances were plotted on plot positions in DCA ordinations in order to summarize the species· responses to environmental variation in each area. Variation in vegetation in the total data set (500 meso sample plots) was partitioned onto two sets of explantory variables (environmental and climatic/geographical) by use of CCA, in order to find the relative importance of environmental and climatic/geographical variation. The fraction of variation exclusively explained by environmental variables was about 1 7%, while only 5% of the variation was explained exclusively by climatic variables. The variation shared by both sets of variables was about 8%. The main vegetational gradients and environmental/climatic/geographical complex-gradients in the total data set were found by DCA and subsequent interpretation of axes. The main complex-gradients found by separate analyses of data from each reference area, were reflected along the DCA axes in total ordinations, but differences between areas with respect to positions along both environmental and climatic/geographical gradients were also evident. Meso plot occurrences of selected species were plotted in a DCA ordination of the total data set, with variation exclusively due to climatic/geographical variables removed, in order to express regional similarities and differences in the species· responses to the environment. The different patterns of species· distributions in the DCA ordination were discussed in the light of their use as indicators of specified environmental conditions.

Exploring the functional strategies adopted by coastal plants along an ecological gradient by means of morpho-functional traits

2021 ◽  
Author(s):  
Daniela Ciccarelli ◽  
Cleusa Bona
Keyword(s):  
Soil Moisture ◽  
Functional Traits ◽  
Environmental Conditions ◽  
C4 Photosynthesis ◽  
Abiotic Factors ◽  
Sand Dunes ◽  
Species Abundance ◽  
Organic Matter Content ◽  
Strong Interactions ◽  
Ecological Gradient

<p>Coastal dunes are characterised by strong interactions between biotic and abiotic factors along a short gradient from the shoreline to the inland region. We carried out an ecological analysis of the vegetation in a protected area of the Italian coast to evaluate the relationships among species abundance; the occurrence of morphoanatomical traits related to leaves, stems and roots; and soil variables. Three transects were established perpendicular to the shoreline with 27 plots distributed in the frontal dunes, back dunes, and temporarily wet dune slacks.</p><p>The analysis based on community weighted mean values is consistent with the ecological constraints along the shoreline-inland gradient. The front-plots were characterised by the presence of pioneer communities (with succulent leaves as evidenced by the high limb thickness values and the low LDMC values) that are well adapted to the harsh environmental conditions of these habitats. Farther from the sea, the back-plot vegetation was characterised by functional traits (especially high LDMC values) that are consistent with the less-extreme ecological conditions. Last, the slack-plots seemed to be very interesting from a functional point of view. They were dominated by geophytes that had adopted C4 photosynthesis and had amphistomatic leaves and abundant aerenchyma in the roots.</p><p>The native vs. invasive status, C4 photosynthesis, leaf trichomes and aerenchyma in the roots were significantly correlated with soil moisture, organic matter content and pH. These results demonstrate the usefulness of anatomical traits (especially those of the root system) in understanding the functional strategies adopted by plants.</p><p>Last, invasive species tended to occupy plots with high levels of soil moisture, and they were not abundant in the habitats with more arid conditions. These data confirmed that alien species are less adapted to the harsh environmental conditions of coastal sand dunes. Increasing the spatial extent of the study area and integrating other functional traits, such as ecophysiological or regenerative characteristics, into the study may allow the development of a more comprehensive functional framework of the invasion process. All this information can be used to develop appropriate management strategies for coastal dune ecosystems.</p>

Retrieval and validation of soil moisture from FRS-1 data set of radar imaging satellite (RISAT-1)

2017 ◽  
Vol 10 (20) ◽  
Author(s):  
Kishan Singh Rawat ◽  
Vinay Kumar Sehgal ◽  
Sanatan Pradhan ◽  
Shibendu S. Ray
Keyword(s):  
Soil Moisture ◽  
Radar Imaging ◽  
Data Set

A generally applicable pedotransfer function that estimates field capacity and permanent wilting point from soil texture and bulk density

2008 ◽  
Vol 88 (5) ◽  
pp. 761-774 ◽  
Author(s):  
J. A. P. Pollacco
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Bulk Density ◽  
Soil Texture ◽  
The United States ◽  
Pedotransfer Functions ◽  
Pedotransfer Function ◽  
Data Set ◽  
Wide Range ◽  
Fitting Parameters

Hydrological models require the determination of fitting parameters that are tedious and time consuming to acquire. A rapid alternative method of estimating the fitting parameters is to use pedotransfer functions. This paper proposes a reliable method to estimate soil moisture at -33 and -1500 kPa from soil texture and bulk density. This method reduces the saturated moisture content by multiplying it with two non-linear functions depending on sand and clay contents. The novel pedotransfer function has no restrictions on the range of the texture predictors and gives reasonable predictions for soils with bulk density that varies from 0.25 to 2.16 g cm-3. These pedotransfer functions require only five parameters for each pressure head. It is generally accepted that the introduction of organic matter as a predictor improves the outcomes; however it was found by using a porosity based pedotransfer model, using organic matter as a predictor only modestly improves the accuracy. The model was developed employing 18 559 samples from the IGBP-DIS soil data set for pedotransfer function development (Data and Information System of the International Geosphere Biosphere Programme) database that embodies all major soils across the United States of America. The function is reliable and performs well for a wide range of soils occurring in very dry to very wet climates. Climatical grouping of the IGBP-DIS soils was proposed (aquic, tropical, cryic, aridic), but the results show that only tropical soils require specific grouping. Among many other different non-climatical soil groups tested, only humic and vitric soils were found to require specific grouping. The reliability of the pedotransfer function was further demonstrated with an independent database from Northern Italy having heterogeneous soils, and was found to be comparable or better than the accuracy of other pedotransfer functions found in the literature. Key words: Pedotransfer functions, soil moisture, soil texture, bulk density, organic matter, grouping

scholarly journals The Murrumbidgee soil moisture monitoring network data set

2012 ◽  
Vol 48 (7) ◽  
Author(s):  
A. B. Smith ◽  
J. P. Walker ◽  
A. W. Western ◽  
R. I. Young ◽  
K. M. Ellett ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Monitoring Network ◽  
Network Data ◽  
Data Set ◽  
Soil Moisture Monitoring

scholarly journals Development of a hydrometeorological forcing data set for global soil moisture estimation

2005 ◽  
Vol 25 (13) ◽  
pp. 1697-1714 ◽  
Author(s):  
A. A Berg ◽  
J. S. Famiglietti ◽  
M. Rodell ◽  
R. H. Reichle ◽  
U. Jambor ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Data Set ◽  
Global Soil ◽  
Moisture Estimation

scholarly journals On the sources of global land surface hydrologic predictability

2013 ◽  
Vol 17 (7) ◽  
pp. 2781-2796 ◽  
Author(s):  
S. Shukla ◽  
J. Sheffield ◽  
E. F. Wood ◽  
D. P. Lettenmaier
Keyword(s):  
Soil Moisture ◽  
Land Surface ◽  
Snow Water Equivalent ◽  
Forecast Skill ◽  
Streamflow Prediction ◽  
Infiltration Capacity ◽  
Forecast Period ◽  
Data Set ◽  
Model Based ◽  
Snow Water

Abstract. Global seasonal hydrologic prediction is crucial to mitigating the impacts of droughts and floods, especially in the developing world. Hydrologic predictability at seasonal lead times (i.e., 1–6 months) comes from knowledge of initial hydrologic conditions (IHCs) and seasonal climate forecast skill (FS). In this study we quantify the contributions of two primary components of IHCs – soil moisture and snow water content – and FS (of precipitation and temperature) to seasonal hydrologic predictability globally on a relative basis throughout the year. We do so by conducting two model-based experiments using the variable infiltration capacity (VIC) macroscale hydrology model, one based on ensemble streamflow prediction (ESP) and another based on Reverse-ESP (Rev-ESP), both for a 47 yr re-forecast period (1961–2007). We compare cumulative runoff (CR), soil moisture (SM) and snow water equivalent (SWE) forecasts from each experiment with a VIC model-based reference data set (generated using observed atmospheric forcings) and estimate the ratio of root mean square error (RMSE) of both experiments for each forecast initialization date and lead time, to determine the relative contribution of IHCs and FS to the seasonal hydrologic predictability. We find that in general, the contributions of IHCs to seasonal hydrologic predictability is highest in the arid and snow-dominated climate (high latitude) regions of the Northern Hemisphere during forecast periods starting on 1 January and 1 October. In mid-latitude regions, such as the Western US, the influence of IHCs is greatest during the forecast period starting on 1 April. In the arid and warm temperate dry winter regions of the Southern Hemisphere, the IHCs dominate during forecast periods starting on 1 April and 1 July. In equatorial humid and monsoonal climate regions, the contribution of FS is generally higher than IHCs through most of the year. Based on our findings, we argue that despite the limited FS (mainly for precipitation) better estimates of the IHCs could lead to improvement in the current level of seasonal hydrologic forecast skill over many regions of the globe at least during some parts of the year.

scholarly journals Separating damage from environmental effects affecting civil structures for near real-time damage detection

2017 ◽  
Vol 17 (4) ◽  
pp. 850-868 ◽  
Author(s):  
William Soo Lon Wah ◽  
Yung-Tsang Chen ◽  
Gethin Wyn Roberts ◽  
Ahmed Elamin
Keyword(s):  
Damage Detection ◽  
Real Time ◽  
Environmental Effects ◽  
Environmental Conditions ◽  
Principal Component ◽  
Detection Methods ◽  
Real Time Monitoring ◽  
Civil Structures ◽  
Data Set ◽  
Wide Range

Analyzing changes in vibration properties (e.g. natural frequencies) of structures as a result of damage has been heavily used by researchers for damage detection of civil structures. These changes, however, are not only caused by damage of the structural components, but they are also affected by the varying environmental conditions the structures are faced with, such as the temperature change, which limits the use of most damage detection methods presented in the literature that did not account for these effects. In this article, a damage detection method capable of distinguishing between the effects of damage and of the changing environmental conditions affecting damage sensitivity features is proposed. This method eliminates the need to form the baseline of the undamaged structure using damage sensitivity features obtained from a wide range of environmental conditions, as conventionally has been done, and utilizes features from two extreme and opposite environmental conditions as baselines. To allow near real-time monitoring, subsequent measurements are added one at a time to the baseline to create new data sets. Principal component analysis is then introduced for processing each data set so that patterns can be extracted and damage can be distinguished from environmental effects. The proposed method is tested using a two-dimensional truss structure and validated using measurements from the Z24 Bridge which was monitored for nearly a year, with damage scenarios applied to it near the end of the monitoring period. The results demonstrate the robustness of the proposed method for damage detection under changing environmental conditions. The method also works despite the nonlinear effects produced by environmental conditions on damage sensitivity features. Moreover, since each measurement is allowed to be analyzed one at a time, near real-time monitoring is possible. Damage progression can also be given from the method which makes it advantageous for damage evolution monitoring.

scholarly journals Drought Propagation in Semi-Arid River Basins in Latin America: Lessons from Mexico to the Southern Cone

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1564 ◽  
Author(s):  
Melanie Oertel ◽  
Francisco Meza ◽  
Jorge Gironás ◽  
Christopher A. Scott ◽  
Facundo Rojas ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Drought Monitoring ◽  
Moisture Index ◽  
Data Set ◽  
Basin Scale ◽  
Soil Moisture Index ◽  
Streamflow Data ◽  
Governmental Institutions ◽  
Negative Impacts ◽  
Combined Data

Detecting droughts as early as possible is important in avoiding negative impacts on economy, society, and environment. To improve drought monitoring, we studied drought propagation (i.e., the temporal manifestation of a precipitation deficit on soil moisture and streamflow). We used the Standardized Precipitation Evapotranspiration Index (SPEI), Standardized Streamflow Index (SSI), and Standardized Soil Moisture Index (SSMI) in three drought-prone regions: Sonora (Mexico), Maipo (Chile), and Mendoza-Tunuyán (Argentina) to study their temporal interdependence. For this evaluation we use precipitation, temperature, and streamflow data from gauges that are managed by governmental institutions, and satellite-based soil moisture from the ESA CCI SM v03.3 combined data set. Results confirm that effective drought monitoring should be carried out (1) at river-basin scale, (2) including several variables, and (3) considering hydro-meteorological processes from outside its boundaries.

scholarly journals Procedures for evaluating the tolerance of cassava genotypes to postharvest physiological deterioration

2015 ◽  
Vol 50 (7) ◽  
pp. 562-570 ◽  
Author(s):  
Marcela Tonini Venturini ◽  
Vanderlei da Silva Santos ◽  
Eder Jorge de Oliveira
Keyword(s):  
Soil Moisture ◽  
High Temperature ◽  
Low Temperature ◽  
Environmental Conditions ◽  
Fungicide Treatment ◽  
High Soil Moisture ◽  
Root Position ◽  
Postharvest Physiological Deterioration ◽  
Significant Interference ◽  
Diagrammatic Scale

Abstract: The objective of this work was to define procedures to assess the tolerance of cassava genotypes to postharvest physiological deterioration (PPD) and to microbial deterioration (MD). Roots of six cassava genotypes were evaluated in two experiments, during storage under different environmental conditions: high temperature and low soil moisture; or low temperature and high soil moisture. Roots were treated or not with fungicide (carbendazim) before storage. Genotype reactions to MD and PPD were evaluated at 0, 2, 5, 10, 15, 20, and 30 days after harvest (DAH), in the proximal, medial, and distal parts of the roots. A diagrammatic scale was proposed to evaluate nonperipheral symptoms of PPD. Fungicide treatment and root position did not influence PPD expression; however, all factors had significant effect on MD severity. Genotypes differed as to their tolerance to PPD and MD. Both deterioration types were more pronounced during periods of higher humidity and lower temperatures. The fungicide treatment increased root shelf life by reducing MD severity up to 10 DAH. Whole roots showed low MD severity and high PPD expression up to 10 DAH, which enabled the assessment of PPD without significant interference of MD symptoms during this period.

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