Vegetation indices are calculated from reflectance data of discrete spectral bands. The reflectance signal in the visible spectral range is dominated by the optical properties of photosynthetic pigments in plant leaves. Numerous spectral indices have been proposed for the estimation of leaf pigment contents, but the efficacy of different indices for prediction of pigment content and composition for species-rich communities is unknown. Assessing the ability of different vegetation indices to predict leaf pigment content we identify the most suitable spectral indices from an experimental dataset consisting of field-grown high light exposed leaves of 33 angiosperm species collected in two sites in Mallorca (Spain) with contrasting leaf anatomy and pigment composition. Leaf-level reflectance spectra were recorded over the wavelength range of 400 – 900 nm and contents of chlorophyll a, chlorophyll b, total carotenoids, and anthocyanins were measured in 33 species from different plant functional types, covering a wide range of leaf structures and pigment content, five-fold to more than 10-fold for different traits. The best spectral region for estimation of leaf total chlorophyll content with least interference from carotenoids and anthocyanins was the beginning of near-infrared plateau well beyond 700 nm. Leaves of parallel-veined monocots and pinnate-veined dicots had different relationships between vegetation indices and pigments. We suggest that the nature and role of “far-red” chlorophylls which absorb light at longer wavelengths than 700 nm constitute a promising target for future remote sensing studies.
The objectives of this study were to assess the variability in soil properties affecting salinity and alkalinity, and to analyze
spatial distribution patterns of salinity (EC) and alkalinity (ESP) in the plain, which was used irrigation agriculture with
low quality waters. Soil samples were collected from 0–30cm, 30–60cm, 60–90cm and 90–120cm soil depths at 60 sampling sites.
Soil pH had the minimum variability, and hydraulic conductivity (Ks) had the maximum variability at all depths. The mean values
of pH, EC, ESP and Ks increased while the mean values of CEC decreased with soil depth. Values pH, EC and ESP were generally
high in the east and northeastern sides. Soil properties indicated moderate to strong spatial dependence. ESP and pH were
moderately spatially dependent for three of the four depths, EC exhibited moderate spatial dependence for one of the four
depths, CEC had a moderate spatial dependence at all depths, and Ks exhibited a strong spatial dependence. EC, CEC, and ESP
were considerably variable in small distances. The spatial variability in small distances of EC, CEC, pH and ESP generally
increased with depth. All geostatistical range values were greater than 1230m. It was inferred that the strong spatial dependency
of soil properties would be resulted in extrinsic factors such as ground water level, drainage, irrigation systems and microtopography. 相似文献
Physiological processes characteristic of the fatigue of legs mainly appear when the worker’s activity requires standing. If the processes are intensive and regular, various diseases of legs, such as varicose veins and musculoskeletal disorders of legs and feet, can develop. Therefore, methods of reducing the fatigue of legs are important in occupational health protection. Air jet massage technology was developed and an appropriate massage device was built by the authors. The massage head turning around the lower leg and moving up and down gradually covers the leg’s surface. To determine the efficiency of the massage, fatigue processes were studied. These studies showed that jet massage effectively reduces both the subjective and objective fatigue symptoms. The device is convenient for use in industry, services, and at home. 相似文献
Regional Environmental Change - Estonia is the only country in Europe that is actively mining oil shale. Oil-shale-burning power plants have been and still are the main sources of heavy metals in... 相似文献
Dendrochronological and oxygen–carbon isotopic analysis was conducted on tree rings collected at two different elevations from three different regions in western Anatolia, Turkey. Tree rings were sampled from Anatolian black pines (Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe) of at least 200?years old through an N–S transect covering Bolu-Mengen (north), Kütahya–Simav, and Antalya–Alanya (south) forests. Cellulose was extracted from 5-year blocks of tree rings from lower to upper altitudes in each region. Dendrochronological site chronologies were built for each of the 6 sites, and response to climate was evaluated. The long-term δ13C chronologies comprising the period 1800–2008 strongly decline by an average of 2.5‰ from the mid-twentieth century, which corresponds with the commencement of industrialization in Turkey. Oxygen isotope (δ18O) time series show dominantly low undulations, although some high-frequency variations of up to 6‰ are also observed. As a result of latitude and continent effects, oxygen isotope values of tree rings show an average of 3‰ increase from south (Antalya) to the north (Bolu). Correlations between carbon isotope ratios yield high positive values indicating that industrial pollution exerts a major control on the δ13C systematics of the studied trees. Corrected δ13C ratios are mostly represented by strong positive responses to variations in temperature and precipitation, whereas δ18O and summer temperature/precipitation are negatively correlated. Tree-ring widths and δ18O display similar responses to the temperature and sensitivity to the climatic impact of historic volcanic eruptions, and changes in the solar irradiance record are also detected in other high-resolution paleoclimate archives for the region. 相似文献
The Rough Cilicia Archaeological Survey Project investigates landscape transformation as a component to its regional survey of ancient Rough Cilicia (south coastal Turkey opposite Cyprus). Rough Cilicia was celebrated during antiquity for pristine cedar forests that stood between 1500 and 1800 m in altitude along the slopes of the Taurus Mountains. Today along the front range of the Taurus Mountains this forest is completely denuded or otherwise replanted with recent growth in the past 80 years. We employ paleoenvironmental analysis of relic cedar forests in the Taurus Mountains to construct a timeline of anthropogenic disturbances associated with population growth over time and thereby assess the sustainability of ancient forestry practices. To obtain these data, the team recovers pollen and carbon samples from geomorphologic trenches excavated in the cedar zone, tree ring data from dendrochronological survey of the existing forest, and archaeological data from remains of ancient highland settlements. Preliminary results indicate that current perspectives about the timing of deforestation in this region are flawed and that the initial deforestation coincided with regional site abandonment and population decline at the end of antiquity. 相似文献
Many pure samples of natural fecal pellets have been collected from mixed small copepods and from the pontellid copepod Anomalocera patersoni in the Ligurian Sea, using a specially designed pellet collection device. Sinking rates of fresh pellets and pellets aged up to 33 days have been determined at 14°C, the mean temperature of the essentially isothermal water column in the Ligurian Sea. Sinking rates of pellets collected during calm sea states increased with increasing pellet volume, but sinking rates of pellets collected during rough sea (Beaufort scale 6) showed little correlation with pellet size. Much of the variability in the sinking rate-pellet size relationships was the result of different pellet composition and compaction, but not pellet age. Pellets produced from laboratory diets of phytoplankton and phytoplankton-sediment mixes showed the expected wide variability in sinking rates, with sediment-ballasted pellets sinking much faster than pellets produced from pure algal diets; thus determination of vertical material fluxes in the sea using laboratory-derived fecal pellet sinking rates is unwarranted. Natural pellet sinking data for small copepods and A. patersoni have been combined with similar data for euphausiids, to yield sinking rates of roughly two orders of magnitude over three orders of magnitude in pellet volume. Pellets from small copepods sank at speeds too slow to be of much consequence to rapid material flux to the deep sea, but they undoubtedly help determine upper water distribution of materials. Recalculation of fecal pellet mass flux estimates from the literature, using our sinking rate data for natural small copepod pellets, yielded estimates about half those of previously published values. Earlier studies had concluded that small fecal pellets were of lesser significance to total material flux than fecal matter; our recalculation strengthens that conclusion. Pellets from large copepods and euphausiids, however, have the capability to transport materials to great depths, and probably do not substantially recycle materials near the surface. The fact that the majority of pellets which had previously been collected in deep traps by other workers were of a size comparable to pellets from our large copepods supports the contention that these larger pellets are the main ones involved in vertical flux. 相似文献
The objective of this article is to propose a program for the integrated coastal zone management that is required to stimulate
and guide sustainable development of the Mediterranean coastal zone of Turkey.
Improved data collection, quality control, analysis, and data management will provide a firm basis for future scientific understanding
of the East Mediterranean coast of Turkey and will support long-term management. Various innovative procedures were proposed
for a promising ecosystem-based approach to manage coastal wetlands in the Mediterranean: remote data acquisition with new
technologies; environmental quality monitoring program that will provide a baseline for monitoring; linking a Geographic Information
System (GIS) with natural resource management decision routines in the context of operational wetlands, fisheries, tourism
management system; environmental sensitivity analysis to ensure that permitted developments are environmentally sustainable;
and use of natural species to restore the wetlands and coastal dunes and sustain the system processes. The proposed management
scheme will benefit the scientific community in the Mediterranean and the management/planning community in Eastern Turkey. 相似文献