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71.
Romà Ogaya Anna Escolà Daijun Liu Adrià Barbeta Josep Peñuelas 《Journal of Sustainable Forestry》2020,39(4):365-378
ABSTRACTA natural holm oak forest was selectively thinned to test thinning as a tool to reduce tree mortality, increase productivity, and reverse the recent regression of the dominant species (Quercus ilex) induced by climate change. Thinning increased aboveground productivity and reduced stem mortality in this Mediterranean forest during four years just after thinning, contributing to the maintenance of forest functioning under changing climatic conditions. Q. ilex was the only species positively affected by the thinning: stem growth increased for all stem sizes, and mortality was significantly lower in thinned plots. On the contrary, mortality rates of Phillyrea latifolia and Arbutus unedo were not significantly lower. Stem growth increased for P. latifolia only in the smallest stem-size class. Our results highlight the suitability of selective thinning for improving the forest productivity and ensuring the conservation of Mediterranean coppices. Other benefits of selective thinning, such as a decrease in the risk of fire dispersion and an increase in the water supply for human populations, are also discussed. 相似文献
72.
Robert Manuel L. Juárez-Gómez Juan Chaires-Pacheco Mariana Peña-Ramírez Yuri J. 《New Forests》2020,51(2):335-347
New Forests - Spanish red cedar, Cedrela odorata L. (Meliaceae), is a valuable timber tree in tropical American forests. Existing demand for elite individuals endangers the conservation of... 相似文献
73.
Chhourn Orn Rieko Shishido Masahiro Akimoto Ryo Ishikawa Than Myint Htun Ken-Ichi Nonomura Yohei Koide Men Sarom Seng Vang Sakhan Sophany Ouk Makara Takashige Ishii 《Breeding Science》2015,65(5):430-437
A total of 448 samples in five natural populations of wild rice (Oryza rufipogon) were collected in Cambodia. They were examined using 12 SSR and two chloroplast markers to evaluate the degree of variation among populations and the genetic structure within populations. In the two annual populations, the number of plants with homozygous alleles at all 12 SSR loci were high (66.3% and 79.5%), suggesting that these plants propagate mainly through self-pollination. In the three perennial populations, no individuals had all homozygous genotypes, but redundant genotypes resulted from clonal propagation were observed. Percentages of the redundant genotypes were highly varied (3.6%, 29.2% and 86.0%). This may be due to the different stable levels of environmental conditions. As for chloroplast genome, most of the wild plants showed the same chloroplast types as most Indica-type cultivars have. However, plants with different chloroplast types were maintained, even in the same population. In tropical Asian countries, many wild rice populations were observed under similar ecological conditions examined in this study. Therefore, the present results concerning population structure will be important to further elucidate genetic features of wild rice, and will also give strong clues to utilize and conserve wild natural genetic resources. 相似文献
74.
Seasonal patterns of root-surface phosphatase activities in a Mediterranean shrubland. Responses to experimental warming and drought 总被引:2,自引:0,他引:2
Mediterranean ecosystems are water limited and the current general circulation Models (GCM) and ecophysiological models forecast
a warming and a further increase of drought in the next decades. A stronger water stress can decrease the capacity for nutrient
absorption by plants. We conducted a field experiment to simulate forecasted drought and warming in a Mediterranean calcareous
shrubland to assess the performance of root-surface phosphatase activities of the dominant shrub Globularia alypum. These enzyme activities were higher in autumn and spring, when the climate conditions were optimal for plant activity, than
in summer or winter, when there was either lack of water or cold temperatures. A decrease in soil moisture in drought plots
decreased root-surface phosphatase activity (29% in summer and 25% in autumn). The decrease in root-surface phosphatase activity
in drought plots coincided with a decrease in P leaf concentrations and P accumulation in aboveground biomass and loss of
photosynthetic capacity of some dominant shrub species of this ecosystem, and with a tendency to increase total soil-P. These
results suggest that the expected drier conditions in this Mediterranean shrubland in the next decades will slow down the
P uptake by plants, thereby, diminishing the P contents in biomass and increasing total P contents in soil in non-available
forms and that this can be, in part, attributable to a result of the decrease in root-surface phosphatase activity. 相似文献
75.
B. S. Gimeno J. Peñuelas J. L. Porcuna R. A. Reinert 《Water, air, and soil pollution》1995,85(3):1521-1526
High ozone (O3) levels have been recorded in eastern Spain. A project was developed to identify the areas of elevated O3 and determine if these levels were above critical concentrations for plant damage. Thus, a network of bioindicators was established in two Autonomous Communities of Spain: Catalunya (31.930 km2) and Valencia (23.305 km2) to assess O3 phytotoxicity. Three tobacco cultivars, (Bel-W3, Bel-C and Bel-B) were used during the 1994 growing season in both Regions. In Catalunya the highest O3 phytotoxicity was recorded in coastal areas, while the phytotoxicity decreased as plants were grown further in-land. A lower O3 phytotoxicity was observed in coastal sites of the Valencia Autonomous Community, compared to Catalunya, although the O3 injury was observed downwind from Valencia city in the most resistant cultivar Bel-B. The results in the Valencian Community were difficult to interpret, since plant viruses were widely distributed, not only in indicator plants, but also in commercial crops grown in the area. The analysis of O3 concentrations, meteorological parameters and visible injury at the Catalan sites showed that high relative humidity levels could favour O3 phytotoxicity. Therefore, the interactions between O3 exposure and environmental conditions on plant response should be further studied for the establishment of sound critical levels. 相似文献
76.
Henry Zúñiga-Benítez Román Sánchez-Monsalve Gustavo A. Peñuela 《Water, air, and soil pollution》2018,229(10):332
This paper presents the main results obtained using the heterogeneous photocatalysis with TiO2 technology in the removal of the emerging contaminant benzophenone-3 at pilot plant scale in a cylinder parabolic solar collector. In this sense, the effects of the operational parameters, pH and catalyst concentration, were analyzed, and after the use of the response surface methodology, the conditions that, under the experimental range, conduct to a higher removal of the analyte were selected. Additionally, analysis of the total organic carbon content and the biodegradability index (relationship between BDO5 and COD) of the treated samples were carried out. In general, results allowed us to infer that this kind of treatment is effective in removing a considerable percentage of the substrate, and that it could become an effective alternative to water treatment and decontamination. 相似文献
77.
Daniel E. León Henry Zúñiga-Benítez Gustavo A. Peñuela Héctor D. Mansilla 《Water, air, and soil pollution》2017,228(9):361
This study presents the main results about the removal of the antibiotic cefotaxime (CTX) under simulated sunlight radiation using heterogeneous photocatalysis with titanium dioxide (TiO2) and zinc oxide (ZnO) in aqueous solutions. The effects of pH and catalyst initial load on pollutant removal were assessed considering the response surface methodology and a central composite circumscribed experimental design, which allowed to determine the optimized conditions that lead to a higher substrate elimination. Experimental results indicated that evaluated parameters have a significant effect on antibiotic removal in both TiO2 and ZnO suspensions. In addition, the role of photogenerated holes, hydroxyl, and superoxide anion radicals on CTX degradation was evaluated to clarify the reaction mechanism. Finally, analysis of the dissolved organic carbon content in solutions and the antibacterial activity of treated samples showed that photocatalytic treatments were able to reduce a considerable portion of the organic matter present in the systems and its antimicrobial activity. 相似文献
78.
Santana Pedro Henrique Lopes Burak Diego Lang Thiengo Cássio Carlette Peçanha Anderson Lopes Neves Mirna Aparecida Mendonça Eduardo de Sá 《Journal of Soils and Sediments》2020,20(11):4103-4110
Journal of Soils and Sediments - After the greatest environmental disaster in the history of Brazil and the deposition of the iron ore tailings in alluvial regions, the process of revegetation for... 相似文献
79.
80.
Segura Carretero A Cruces-Blanco C Soriano Peña M Cortacero Ramírez S Fernández Gutiérrez A 《Journal of agricultural and food chemistry》2004,52(6):1419-1422
A test mixture of five phytohormones [naphthaleneacetic acid (NAA), naphthoxyacetic acid (NOA), indoleacetic acid (IAA), indolebutyric acid (IBA), and indolepropionic acid (IPA)] was investigated. These compounds were cleanly separated with good resolution by capillary zone electrophoresis with a UV diode array detector using 20 mM sodium phosphate buffer (pH 7.25). The lowest detection limit was obtained for IPA (0.45 mg L(-)(1) or 0.005 mg kg(-)(1)) and the highest for NAA (1.04 mg L(-)(1) or 0.014 mg kg(-)(1)). The method has been applied for tomato samples fortified with the five phytohormones using a liquid-liquid extraction procedure, obtaining recovery percentages ranging from 91 to 109.0%. 相似文献