Search results for "VEGETATION"
showing 10 items of 1069 documents
How Universal Is the Relationship between Remotely Sensed Vegetation Indices and Crop Leaf Area Index? A Global Assessment
2016
This study aims to assess the relationship between Leaf Area Index (LAI) and remotely sensed Vegetation Indices (VIs) for major crops, based on a globally explicit dataset of in situ LAI measurements over a significant set of locations. We used a total of 1394 LAI measurements from 29 sites spanning 4 continents and covering 15 crop types with corresponding Landsat satellite images. Best-fit functions for the LAI-VI relationships were generated and assessed in terms of crop type, vegetation index, level of radiometric/atmospheric processing, method of LAI measurement, as well as the time difference between LAI measurements and satellite overpass. These global LAI-VI relationships were evalu…
Optimal timing of power line rights-of-ways management for the conservation of butterflies
2012
Habitat loss, fragmentation, and degradation are the main threats to biodiversity. Human activities also create new habitat types that might fulfil ecological requirements for a variety of species. This study investigates whether the vegetation clearing (=shrub and tree cutting) on drained mire patches on power line rights-of-ways (ROWs) keep plant communities in an early successional stage and thus provide habitats for mire specialist and non-mire butterflies. It was further studied what would be the optimal clearing interval in terms of butterfly species richness and abundance. The results show that tree height, especially the height of birch, increases linearly over the 7-year period fol…
Corrigendum to “Conservation value of forest plantations for bird communities in western Kenya” [Forest Ecol. Manag. 255 (2008) 3885–3892]
2009
A re-analysis of the bird data revealed a mistake within the database query. Only bird individuals that were heard were integrated in the results leading to lower total richness and number of individuals. In total 115 species and 13,331 individuals were detected of which 41 were forest specialists (43% of all individuals), 40 forest generalists (41%) and 34 forest visitors (16%). The statistical analyses remain very similar. We recorded significant differences in mean bird species richness, number of individuals and relative species richness among the five forest types (Table 1). Multiple pairwise comparisons showed significantly higher numbers of species in natural forest, mixed indigenous…
Weed communities of rice fields in the central Pamir Alai Mountains (Tajikistan, Middle Asia)
2013
The study present results of geobotanical investigations conducted in rice fields in the central Pamir Alai Mts (Tajikistan, Middle Asia), mainly within Syr-Daria, Pyandzh, Zeravshan, Kafirnigan, Khanaka and Surkhandaria river valleys in the years 2009–2011. The researches were focused on classification of plant communities developing within this poorly investigated area. Habitat conditions were checked including conductometry, pH reaction, temperature, depth of water and, for several plots, also soil structure. Altogether 114 phytosociological relevés using the Braun-Blanquet method were sampled. The analyses classified the vegetation into 28 communities including 24 associations. Five new…
Possible markers of traffic-related emissions
2007
Looking for robust indicators of motor vehicle emissions it has been found that brake wear and linings are significant contributors of Cu, Mo and Sb to air particulate matter. These trace elements, whose mutual ratios in airborne particulate matter resulted quite different from those in crustal material, appear to be available fingerprinting tools to identify the contribution of on-road vehicles to traffic-derived particulate matter. In this study, the results of analytical determinations of Cu, Mo and Sb on PM(10), PM(2.5), vegetation and brake dust samples, together with gas (CO, NOx) concentrations, are discussed. Highly significant correlations among Cu, Sb and Mo were observed in parti…
Exploring the validity of the long term data record V4 database for land surface monitoring
2015
The last (and final) version of the Long Term Data Record (LTDR) — Version 4 — has been released recently by NASA. This database includes daily information for all AVHRR (Advanced Very High Resolution Radiometer) channels, as well as ancillary data, since July 1981 up to present. This database is the longest available record of remotely sensed data useful for land surface monitoring, since it allows the estimation of vegetation indices at daily resolution, as well as the daily estimation of land surface temperature (LST). Here, we analyze the fitness of this database for land surface monitoring. To that end, we first estimated NDVI (Normalized Difference Vegetation Index), LST, as well as e…
The ‘recent’ forests of Mount Venda (Padua, Italy): when historical cartography and archaeobotany tell quite a different story
2018
Forests, like agricultural systems and housing, are an integral part of the human landscapes. They evolve over time, not only in response to environmental factors (e.g. climate change) but also in response to developments in human society. This work on the analysis of forest dynamics in Euganean hills is the result of research carried out as part of the research programmes THISTLE (MSCA Fellowship, grant agreement: 656397) and MEMOLA (EU FP7 Project , grant agreement: 613265). The work is focused on two mountains in particular: Monte Venda and Monte della Madonna. The archaeobotanical investigations reveal the presence of ancient forests (since the 14th century) in these areas , although th…
Archaeogenetics and Landscape Dynamics in Sicily during the Holocene: A Review
2021
The Mediterranean islands and their population history are of considerable importance to the interpretation of the population history of Europe as a whole. In this context, Sicily, because of its geographic position, represents a bridge between Africa, the Near East, and Europe that led to the stratification of settlements and admixture events. The genetic analysis of extant and ancient human samples has tried to reconstruct the population dynamics associated with the cultural and demographic changes that took place during the prehistory and history of Sicily. In turn, genetic, demographic and cultural changes need to be understood in the context of the environmental changes that took place…
A methodological approach in the evaluation of the efficacy of treatments for the dimensional stabilisation of waterlogged archaeological wood
2010
Abstract The aim of the work is to set up a methodological approach to verify the effectiveness of the treatments of decayed waterlogged archaeological wood and to point out the proper thermo-hygrometric conditions for its preservation after treatment. The treatments were performed on wood samples of maritime pine (Pinus pinaster Aiton), oak (Quercus sp. caducifolia), elm (Ulmus cf. minor) and strawberry tree (Arbutus unedo L.), obtained from stems pertaining to the original vegetation found in the excavation site of the Ancient Ships in Pisa (Italy), and dated from seventh century BC to second century AD The utilised products were: Polyethylene Glycols (PEG) of various molecular weights, a…
1200 years of decadal-scale variability of Mediterranean vegetation and climate at Pantelleria Island, Italy.
2013
A new sedimentary sequence from Lago di Venere on Pantelleria Island, located in the Strait of Sicily between Tunisia and Sicily was recovered. The lake is located in the coastal infra-Mediterranean vegetation belt at 2 m a.s.l. Pollen, charcoal and sedimentological analyses are used to explore linkages among vegetation, fire and climate at a decadal scale over the past 1200 years. A dry period from ad 800 to 1000 that corresponds to the 'Medieval Warm Period' (WMP) is inferred from sedimentological analysis. The high content of carbonate recorded in this period suggests a dry phase, when the ratio of evaporation/precipitation was high. During this period the island was dominated by thermop…