Search results for "Shrub"
showing 10 items of 101 documents
MODELING THE SHRUB ENCROACHMENT IN THE NORTHERN CHIHUAHUAN DESERT GRASSLANDS WITH A CELLULAR AUTOMATA MODEL
2014
Trees and shrubs in the city of Bari (Italy)
2021
The authors recorded in the city of Bari 221 specific and infraspecific taxa, used as onramentals, belonging to 126 genera of 64 families with a prevalence of exotic species over native ones. The study is preparatory to the redevelopment of urban green areas concerning the recent Municipal Regulation on green spaces in the city. The flora investigated is rich in elements native to Italy. Anyway, the most common species are commonly used as ornamental also in the other regions of Italy. Argania spinosa, Ceiba speciosa, Cyperus papyrus, Euphorbia ingens, Ficus rubiginosa, and Jacaranda mimosifolia are species less commonly used and noteworthy, because at their climatic limit.
Evolution of growth form in epiphytic Dissochaeteae (Melastomataceae)
2001
Abstract We trace the evolution of root climbing and scrambling in Dissochaeteae and Sonerileae, two closely related groups that comprise the majority of Old World climbing Melastomataceae. The morphological and anatomical adaptations of the different climbers are interpreted in the context of a phylogeny based on chloroplast (cp) DNA sequences of the ndhF gene, generated for 31 representatives of Dissochaeteae and Sonerileae/Oxysporeae plus nine outgroups. For 20 of these taxa, the ndhF sequences were combined with cpDNA rpl16 intron sequences to obtain higher statistical support. Parsimony, minimum evolution, and maximum likelihood approaches yield congruent topologies that imply that scr…
Determining the potential impacts of fire and different land uses on splash erosion in the margins of drylands
2021
Abstract This research aimed to estimate the splash erosion and its evolution during the first months in specific land uses after a forest fire. The study area was located in Congosto (North-West Spain), in the margins of Spanish drylands, after a wildfire occurred in May 2012, which burned 15.56 ha of scrubland and Pinus reforestation. Two different burned land uses were selected and compared to control areas: i) burned pine forest; and, scrublands. Rainfall intensity and the number, sizes and speed of raindrops were measured by an optical disdrometer and soil loss by funnels. Moreover, infiltration, soil moisture content, aggregate stability, water repellence, pH and organic matter were a…
Impact of Land Cover Change Induced by a Fire Event on the Surface Energy Fluxes Derived from Remote Sensing
2015
Forest fires affect the natural cycle of the vegetation, and the structure and functioning of ecosystems. As a consequence of defoliation and vegetation mortality, surface energy flux patterns can suffer variations. Remote sensing techniques together with surface energy balance modeling offer the opportunity to explore these changes. In this paper we focus on a Mediterranean forest ecosystem. A fire event occurred in 2001 in Almodovar del Pinar (Spain) affecting a pine and shrub area. A two-source energy balance approach was applied to a set of Landsat 5-TM and Landsat 7-EMT+ images to estimate the surface fluxes in the area. Three post-fire periods were analyzed, six, seven, nine, and 11 y…
The Role of Fire in Achieving the Sustainable Development Goals of the United Nations
2019
The Sustainable Development Goals (SDGs) of the United Nations do not mention Fire as a key factor in achieving an environmentally-friendly human society. This paper reviews the key aspects of the impact of fire that make it necessary to update the SDGs. Upon reviewing the scientific literature, it was found that fire has been part of the Earth System for the last 400 million years, and that it is part of biogeochemical cycles. From a geological perspective, fire shaped the current Earth System. Humans have used fire in the last million years as hunter-gatherers, and the last Pleistocene period evolved with the presence of fire. Since the Neolithic revolution, humankind spread the use of fi…
Syntaxonomy and ecology of mesophilous scrub vegetation in Tajikistan (Middle Asia)
2022
Aims: In this paper we propose the first syntaxonomic classification for the mesophilous scrub vegetation in Tajikistan with some remarks on their environmental variability. Methods: Altogether 120 relevés were sampled using the standard, seven-degree cover-abundance scale of Braun-Blanquet, in 2015–2021. They were classified by the modified TWINSPAN method using the four step interval scale with cutoff levels of 0%, 2%, 5% and 10% and total inertia as a measure of cluster heterogeneity. Diagnostic species were identified using the phi coefficient as a fidelity measure. Detrended Correspondence Analysis (DCA) was used to determine the relationship between the sampled plots, vegetation units…
Comparison of neophyte communities of Robinia pseudoacacia L. and Acer negundo L. in the eastern Baltic Sea region cities of Riga and Kaunas
2015
Abstract In this study, we examined the species composition of neophyte communities of Robinia pseudoacacia and Acer negundo and compared the site conditions of the urban environment of two cities—Riga and Kaunas. Eighty-five plots of A. negundo and R. pseudoacacia communities were selected. Within each plot, all of the vascular plant species were recorded, and their abundance was estimated in 2014. Composite soil samples of the 0–10 cm mineral topsoil were collected for the estimation of the soil chemical properties at nine systematically distributed points in each sample plot. The soil pH KCL , exchangeable bases, total nitrogen, total organic matter, C/N ratio, and concentrations of the …
Growth and defense in deciduous trees and shrubs under UV-B
2005
Abstract Reflection by waxy or resinous surface structures and hairs, repair reactions of biomolecules and induction of different sheltering components provide the means of plant protection from harmful solar UV-B radiation. Secondary products, especially flavonoids and phenolic acids as defense components are also important in plant tolerance to UV-B, fulfilling the dual role as screens that reduce UV-B penetration in plant tissues, and as antioxidants protecting from damage by reactive oxidant species. Plants are sensitive to UV-B radiation, and this sensitivity can be even more clone-specific than species-specific. The results available in the literature for deciduous trees and shrubs in…
Productivity of an Atriplex halimus shrubbery and effects of grazing on lambs
2009
The objectives of this study were to 1) evaluate the productivity and forage quality of Atriplex halimus, 2) investigate modifications to shrub structure induced by grazing, and 3) assess live weight changes in lambs grazing on A. halimus with and without a feed supplement (wheat straw ± barley grain). The results showed that A. halimus had low productivity (approximately 1000 kg DM ha–1) but high tolerance to grazing by lambs, although minor modifications in plant structure due to grazing were observed. Lambs grazing A. halimus as a sole diet lost weight (about 60 g lamb−1 d–1; P < 0.01), probably as a consequence of the high salt content of the forage reducing bot…