174 research outputs found
On the consistencies between CSR plant strategies and Ellenberg ecological indicator values
One strand of British comparative plant ecology has used experimental measurements of innate traits under standardized conditions to confirm plant âstrategiesâ or âfunctional typesâ. The Sheffield (Grime) school has now established CSR-signatures for 1010 species. In contrast, a Central-European approach (GĂśttingen or Ellenberg school) has emphasized the unity of plants with their natural habitats by allocating âecological indicator valuesâ (EIV´s; German: Zeigerwerte) for over 2700 species, which describe the ecological behavior of each species in their plant associations. In this paper we assess the levels of compatibility and congruence between these two approaches using large datasets that include some previously unexamined traits. Despite there being a wide gap between these plant- and environment-based starting points, we discover that both approaches lead to similar conclusions regarding patterns of evolutionary tradeoffs and ecological processes. In particular, the comparisons support the major evolutionary generalization that plant life has, in effect, aligned itself along a continuum between one trait-group that confers rapid acquisition of resources and another that confers long-term resource conservation
Effects of increased autumn temperatures and sub-acute levels of ammonia on post-winter development of four cultivars of winter oilseed rape (Brassica napus L.)
Early planting dates, warm autumns and increased N mineralisation rates may advance the growth of winter crops and also a high supply of nitrogen poses risks of excess biomass accumulation before the winter leading to reduced frost hardiness and excessive leaf loss. Although the number of frost days is currently declining in temperate Europe, events of frost may still create damage in the future in winter crops that have accumulated too much biomass in the preceding autumn.Here we report on a study in which the responses of four cultivars of winter oilseed rape (OSR) to elevated autumn temperatures and subacute levels of ammonia (NH3) were compared. It has been suggested that high concentrations of the gas, e.g. in livestock intensive regions may both act as an airborne fertiliser and reduce the frost hardiness of plants. Advancing treatments were imposed for 88 days in the autumn and consisted of pot grown plants kept in greenhouses without (ELVT) and with elevated concentrations of ammonia (ELVT+A; 195 Οg m-3 NH3). Reference plants (AMB) were raised outdoors, where temperatures were 1.4°C lower than in the greenhouses.After the treatments plants were all overwintered outside to study whether the pre-winter growth advancement was still discernible in the following spring. Shed leaves were collected weekly to follow how much shoot biomass was lost during and after the winter. Cultivars responded differently to warming and exposure to ammonia. Up to the winter shoot biomass was strongly increased by the advancing treatments. However, fi nal shoot mass in the following summer did not differ between cultivars and was unaffected by the higher temperatures in the preceding autumn. Nevertheless, significantly more biomass was observed in ammonia fumigated plants. Higher autumn temperatures increased leaf shedding and advanced fl owering and senescence in the next spring so that plants showed a signifi cantly reduced seed mass, harvest index and oil yield at the fi nal harvest. Obviously, the growth advancement in the preceding autumn by elevated temperatures negatively affected the availability of resources in the following spring. In contrast, plants that were grown at both elevated ammonia and temperature in the autumn showed a delayed fl owering, higher shoot and seed mass, increased harvest index and oil yield. We conclude that growth advancement by elevated autumn temperatures without the re-supply of nutrients increases leaf shedding during winter. Nevertheless, the loss of resources in winter for re-growth in spring will certainly be of minor importance for yield formation as compared to the frost damage resulting from late spring frosts
Hazardous doses of the herbicide imazamox in wild plant species and oilseed rape cultivars
Imidazolinones and crops resistant to these herbicides have successfully been introduced recently in some European countries. Imazamox has a high efficacy, moderate persistence and ecotoxicity, but data on hazardous doses (HD) in non-target plants and species sensitivity distributions (SSDs) are still scarce. To screen a larger variety of plant taxa in standardized vegetative vigor tests, 22 wild plant species and 14 oilseed rape (OSR) cultivars were sown into trays filled with a standard soil. When seedlings had reached the three-to-four leaf stage, plants were exposed to a single application of the herbicide BoleroÂŽ using a commercial pump sprayer. The five treatments corresponded to rates of 0 (control), 0.4, 4, 20 and 40 g/ha of imazamox with latter representing the recommended dose in Switzerland. Two weeks after the application, five plants per treatment were sub-sampled at random and visible injuries and fresh weights were recorded as endpoints for herbicidal effects. Dose-response curves and effective doses (EDs) were fitted using the drc package of the statistical software R and SSDs were obtained using ETX2.0. ED50 varied between 0.006 and 37 g/ha of the active ingredient in Nigella arvensis and Brassica rapa. Several dose-response curves indicated hormetic effects at a hundredth of the recommended field dose. In OSR, exposure to the field rate (40 g/ha) resulted in growth reductions between 28 and 97 % in the non imazamox-tolerant cultivars and in growth stimulations of up to 20 % in imazamox-tolerant cultivars. Responses were unrelated to leaf thickness, growth rates and the taxonomy of the tested species. Hazardous doses were 0.32 g/ha for HD5 and 3.9 g/ha for HD50 indicating that 50 % of the non-target plants would be affected at a tenth of the recommended dose. Based on general herbicide drift values the results suggest that potentially adverse effects may be expected up to a distance of 4 m offsite. Keywords: Clearfield, non-target plants, plant growth tests, plant functional typesSchädliche Dosen des Herbizids Imazamox bei verschiedenen Wildpflanzenarten und RapssortenImidazolinone und gegen diese Herbizide resistente Sorten einiger Kulturarten wurden in den letzten Jahren in einigen Europäischen Ländern erfolgreich eingefĂźhrt. Imazamox hat eine hohe Wirksamkeit, moderate Persistenz und Ăkotoxizität, aber es gibt bislang nur wenige Informationen zu Schaddosen (hazardous doses, HD) in Nichtzielpflanzen und Art-Sensitivitäts-Spektren (species sensitivity distributions, SSDs). Um eine grĂśĂere Anzahl von Pflanzenarten in standardisierten Wachstumstests zu ĂźberprĂźfen, wurden 22 Wildpflanzenarten und 14 Rapssorten in mit Standardboden gefĂźllten Schalen ausgesät. Bei Erreichung des Drei- bis Vierblattstadiums wurden die Pflanzen einmal mittels PumpsprĂźher mit dem Herbizid BoleroÂŽ behandelt. Die fĂźnf eingesetzten Behandlungen entsprachen den Dosen 0 (Kontrolle), 0.4, 4, 20 und 40 g AS/ha, wobei die letztere in der Schweiz die empfohlene Aufwandmenge darstellte. Zwei Wochen nach der Applikation wurden fĂźnf Pflanzen pro Behandlung nach dem Zufallsprinzip geerntet, wobei sichtbare Schäden und Frischgewichte als Wirkkriterien betrachtet wurden. Dosis-Wirkungs-Kurven und effektive Dosen (EDs) wurden mit Hilfe des drc-Pakets mit der Statistik-Software R berechnet und SSDs wurden mittels ETX2.0 abgeleitet. Die ED50-Werte schwankten zwischen 0.006 und 37 g/ha der aktiven Substanz in Nigella arvensis und Brassica rapa. Viele der Dosis-Wirkungs-Beziehungen deuteten hormetische Effekte bei einem Hundertstel der empfohlenen Aufwandmenge an. Bei den nicht Imazamox-toleranten Rapssorten wurden bei der empfohlenen Aufwandmenge (40 g/ha) Wachstumsreduktionen zwischen 28 und 97 % beobachtet, während in den Imazamox-toleranten Sorten Wachstumsstimulationen von bis zu 20 % auftraten. Die beobachteten Effekte standen in keinem Zusammenhang mit der Blattdichte, den Wachstumsraten und der Taxonomie der ĂźberprĂźften Pflanzenarten. Die ermittelten Schaddosen betrugen 0.32 g/ha fĂźr HD5 und 3.9 g/ha fĂźr HD50, was darauf hindeutet, dass 50 % der Nichtzielarten bei einem Zehntel der empfohlenen Aufwandmenge beeinträchtigt wĂźrden. Wenn man die Abdrifteckwerte fĂźr Herbizidanwendungen zu Grunde legt, wären potenziell nachteilige Effekte bis zu einer Entfernung von 4 m zum Feldrand zu erwarten. StichwĂśrter: Clearfield, funktionelle Pflanzentypen, Nichtzielpflanzen, Pflanzenwachstumstest
Tree-rings analysis to reconstruct atmospheric mercury contamination at a historical mining site
Mercury (Hg) is a global environmental concern due to its toxicity (especially high
in methylated form) and the long-range distribution of its gaseous elemental
form (GEM). Hg-contaminated areas, such as abandoned mining sites, pose
intrinsic difficulties for their management and heavy monitoring costs. In these
environments, plant-based solutions may play a key role in the ecosystem quality
assessment and support remediation strategies, combining reliability and costeffectiveness. In this study, we adopted a biomonitoring approach by using tree
rings of four different species collected in the proximity of the miningmetallurgical area of Abbadia San Salvatore, central Italy, a major former Hg
mining district whose reclamation is currently in progress. Our dendrochemical
analysis was aimed at identifying the historical changes of local atmospheric Hg
contamination and at singling out, for the first time in the study area, other
potentially toxic elements (PTEs) associated with the past mining activity.
Collected cores dated back to early as 1940 and provided the temporal
patterns of atmospheric Hg emission vs the produced liquid quantities, so
reconstructing the historical impact of the mining site on nearby terrestrial
ecosystems and resident human population. Current GEM contamination was
found about twenty times lower than that of the fully operational mine periods.
From a first survey on other PTEs, thallium (Tl) and lead (Pb) appeared to be
potentially associated with the mining activity, thus suggesting new working
assumptions for further dendrochemical analyses and for the inclusion of Pb in
human biomonitoring surveys of the Mt. Amiata area, actually not present in the
control list. The results prompt a more thorough assessment by tracking for a
longer time span a critical site that is an ideal open-field lab to study the
ecophysiology of different tree species in relation to environmental behavior of
PTEs for better-assessing wildlife and human exposures
Biomonitoring of airborne fluoride and polycyclic aromatic hydrocarbons in industrial areas of Cordoba, Argentina, using standardized grass cultures of Lolium multiflorum
A biomonitoring study was performed employing standardized grass cultures. Plants of Lolium multiflorum were exposed at 4 industrial sites over three?month periods in two seasons (dry and rainy) and the biomass produced was used for subsequent measurements of fluoride, polycyclic aromatic hydrocarbons (phenanthrene, anthracene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]â anthracene and benzo[g,h,i]perylene), total chlorophyll, malondialdehyde, water, and sulfur content. The total content of polycyclic aromatic hydrocarbons (PAHs) revealed seasonal variations, with the highest values corresponding to the dry season, although this species showed a high retention capacity of PAHs during rainy season. In addition, sampling sites with high vehicular traffic and metal?mechanical industries were associated with the highest content of PAHs. Furthermore, physiological degradation associated with anthropogenic activities in the sampling sites was observed. Fluoride content in the biomonitor was associated with the production and use ofcement, which was higher in the dry season.Fil: Rodriguez, Judith Hebelen. Consejo Nacional de Investigaciones CientĂficas y TĂŠcnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto Multidisciplinario de BiologĂa Vegetal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂsicas y Naturales. Instituto Multidisciplinario de BiologĂa Vegetal; ArgentinaFil: Wannaz, Eduardo Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂŠcnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto Multidisciplinario de BiologĂa Vegetal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂsicas y Naturales. Instituto Multidisciplinario de BiologĂa Vegetal; ArgentinaFil: Franzaring, Jurgen. Universidad de Hohenheim. Instituto de Paisaje y EcologĂa Vegetal. Especialidad En EcologĂa Vegetal y Ecotoxicologia; AlemaniaFil: Klumpp, Andreas. Universidad de Hohenheim. Instituto de Paisaje y EcologĂa Vegetal. Especialidad En EcologĂa Vegetal y Ecotoxicologia; AlemaniaFil: Fangmeier, Andreas. Universidad de Hohenheim. Instituto de Paisaje y EcologĂa Vegetal. Especialidad En EcologĂa Vegetal y Ecotoxicologia; AlemaniaFil: Pignata, Maria Luisa. Consejo Nacional de Investigaciones CientĂficas y TĂŠcnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto Multidisciplinario de BiologĂa Vegetal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂsicas y Naturales. Instituto Multidisciplinario de BiologĂa Vegetal; Argentin
Accumulation of Aluminium and Physiological Status of Tree Foliage in the Vicinity of a Large Aluminium Smelter
A pollution gradient was observed in tree foliage sampled in the vicinity of a large aluminium production facility in Patagonia (Argentina). Leaves of Eucalyptus rostrata, and Populus hybridus and different needle ages of Pinus spec. were collected and concentrations of aluminium (Al) and sulphur (S) as well as physiological parameters (chlorophyll and lipid oxidation products) were analyzed. Al and S concentrations indicate a steep pollution gradient in the study showing a relationship with the physiological parameters in particular membrane lipid oxidation products. The present study confirms that aluminium smelting results in high Al and sulphur deposition in the study area, and therefore further studies should be carried out taking into account potentially adverse effects of these compounds on human and ecosystem health
Investigations on plant functional traits, epidermal structures and the ecophysiology of the novel bioenergy species Sida hermaphrodita Rusby and Silphium perfoliatum L.
A growth experiment was performed with different accessions of the novel bioenergy species Sida hermaphrodita Rusby (Fanpetals, Malvaceae) and Silphium perfoliatum L. (Cup Plant, Asteraceae) to study differences between the perennial shrubs and the variation among biotypes. Non-destructive assessments (phenology, leaf numbers, height, SPAD and gas exchange) and several harvests were conducted to examine growth, allometry and the quality of shoot material (C:N, raw ash, protein, fibre, fat, calorific value and leafδ13C). In addition to the functional analyses, epidermal structures of two widely used accessions were addressed to give insight into anatomical properties of the species.
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In the establishment phase, productivity was higher on average in S. hermaphrodita than in S. perfoliatum since latter remains in the rosette stage in the first year. While the accessions of S. hermaphrodita did not significantly differ in growth, functional traits and forage quality, S. perfoliatum showed large biotypic variation. Leaf water and ash contents, raw protein and fat levels were higher in latter species, while raw fibre contentswere twice as highin S. hermaphrodita. At the end of the season, the calorific value of senesced stems of S. hermaphrodita proved to be higher than that of senesced leaves of S. perfoliatum pointing to its suitability of as a solid fuel.
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Despite the shorter longevity, lower SPAD and smaller size, the delicate leaves of S. hermaphrodita had more stomata, higher photosynthetic rates and higher stomatal conductances than the robust leaves of S. perfoliatum. Less negative δ13C signatures in S. perfoliatum (-27.3 â°) compared to S. hermaphrodita (-30.24 â°), point to the potentially higher water use efficiency of S. perfoliatum. Further investigations on the relationships between leaf properties, carbon acquisition and stomatal conductance under dry conditions may serve to select productive lines of the bioenergy species on marginal land thus avoiding conflicts with the farming of food crops
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