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R. M. Godinho M. C. Freitas H. Th. Wolterbeek 《Journal of Atmospheric Chemistry》2004,49(1-3):355-361
The present work evaluates the stress effects in two epiphytic lichen species with different thallus morphology, the foliose Parmelia caperata and the fruticose Evernia prunastri, as resulting from transplanting from an unpolluted to an air-polluted area. Lichen samples were collected in Portugal in a clean area, during the spring 2003, and transplanted (1) to the same zone nearby and (2) to a polluted area as affected by an industrial complex. Transplant samples were taken periodically during four months in both places. At the same time lichen samples from the clean-air site native (in-situ) populations were also collected. For each sample were measured the chlorophyll content, the chlorophyll degradation and the cell membrane damage, the latter represented by leacheate conductivity. During the experiment the meteorological conditions were registered. The results indicate the absence of stress effects of transplanting as such, and suggest that leachate conductivity may be the more sensitive indicator of general lichen vitality. 相似文献
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Jesús M. Castillo Pablo Leira-Doce Alfredo E. Rubio-Casal Enrique Figueroa 《Estuarine, Coastal and Shelf Science》2008,78(4):819-826
Spartina species are commonly used for salt marsh manipulative projects, where aboveground and belowground biomasses are functional traits that play important roles, showing high spatial and temporal variations. This work analyses variations in AGB and BGB of Spartina maritima and abiotic environmental parameters along a chronosequence of six marshes created from 1997 to 2003 with disparate sediment dynamics, and adjacent natural marshes and unvegetated tidal flats. S. maritima behaved as an autogenic engineer, as its colonization of bare sediments yielded abiotic environmental changes: specifically, bed level rise accompanied by higher oxygenation and salinity. These modifications of the environment were site-specific, depending mainly on sedimentary dynamics. At the same time, abiotic environmental changes determined biomass production rates of S. maritima that were higher in more-accreting marshes; however, AGB was kept constant from early in its development (2 years). The increase in BGB with elevation seemed to be related to the inhibition of subsurface tissue development in anoxic sediments. Biomass accumulation and production varied markedly, depending on the spatial scale, indicating the relevance of the plot size chosen for the analysis of biomass of cordgrasses. Our results show that managers of salt marshes should consider sedimentary dynamics carefully when setting realistic expectations for success criteria of created and restored wetlands. 相似文献
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Rehabilitation of damaged reefs: Outcome of the use of recently broken coral fragments and healed coral fragments of pocilloporid corals on rocky boulders 
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下载免费PDF全文 The use of two types of coral transplants on rock boulders was evaluated as a low‐cost alternative for rehabilitation of live coral coverage in localities whose reef structure has been reduced considerably. Transplant success between recently broken coral fragments (BCF) and healed coral fragments (HCF) was compared assuming that initial fragmentation accelerates the attachment of corals by regeneration stimulation. Two sets of both types of transplants were started during the dry and rainy seasons to contrast the effect of environmental stability on transplant survival, vertical growth and horizontal growth over 12 months. The technique provided adequate conditions for coral development, as transplants responded satisfactorily. BCF showed higher success than HCF in attaching to the substrate (up to 98 ± 4% versus 86.4 ± 18.9% after 9 months) during both seasons and also showed a greater increase in height (209.63 ± 43.65% versus 124 ± 15.83%) and diameter (107.26 ± 25.75% versus 99.98 ± 19.74%) during the rainy season. Boat anchorage caused mortality in transplants started during the dry season (less than 10% for BCF versus 37.2% for HCF) while the impact of Hurricane Polo in October 2014 caused higher mortality in transplants started during the rainy season (up to 55%). We conclude that (i) coral transplantation on rock boulders is a good choice to restore damaged coral communities, (ii) BCF seems to be the best source of transplants for pocilloporid corals, and (iii) although high light availability during the rainy season enhances transplant growth, the stable, low energy conditions in the dry season facilitate initial transplant attachment and high survival. 相似文献
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Six locations across mainland Portugal were selected for exposing Parmelia sulcata, for a one-year period (8 months for one site), with simultaneous measurement of total (dry + wet) deposition (one-month periods). The exposed lichens and the total (dry + wet) deposition were analysed for cobalt contents by INAA (instrumental neutron activation analysis) and ICP-MS (inductively coupled plasma mass spectroscopy), respectively. The designated wet deposition was evaluated through the collected water volume; the designated dry deposition was assessed after the (dried) residual mass of the wet deposition. An excellent agreement between Co contents in exposed lichens and the cumulative (1) Co contents in the dry deposition, (2) dry deposition, and (3) wet deposition has been found for the locations with alternate drought and precipitation months, high dry deposition, and high Co contents in the latter. Continuous rainfall was found to hinder the Co accumulation in the lichen due to its release from the lichen and/or lower Co contents in the dry deposition. At three locations, P. sulcata Co contents, after subtraction of the background (before exposure), equalled or exceeded the Co contents in the cumulative dry deposition at the end of the exposure time. The optimal exposure period for this species likely depends on the exposure conditions. 相似文献
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A Machado Z Šlejkovec J. T. Van Elteren M. C. Freitas M. S. Baptista 《Journal of Atmospheric Chemistry》2006,53(3):237-249
Arsenic and its chemical species were determined in transplanted lichens (Parmelia caperata) and tree bark (Platanus hybrida), in order to get a better understanding of their atmospheric cycling and the suitability of these materials for biomonitoring purposes. Various strategies were used (discontinuous and cumulative exposure of transplants) to biomonitor two locations in Portugal, viz. the northern Lisbon area and Sines, both highly industrialised areas.Analytical techniques comprised instrumental nuclear activation analysis (INAA), inductively coupled plasma-mass spectrometry (ICP-MS) and high performance liquid chromatography-hydride generation atomic fluorescence spectrometry (HPLC-HGAFS) for determination of total arsenic in solid materials, total arsenic in extracts of solid materials and arsenic species in extracts of solid materials, respectively.Only a fraction (up to 50%) of the extracted arsenic species could be identified and quantified in the transplanted lichens, being mainly inorganic arsenic and some methylated arsenic species. Since in a previous study these methylated arsenic species were not found in aerosols collected in the same area, it is probable that the lichen transplants studied (Parmelia caperata) do not behave as genuine passive biomonitors but are able to actively methylate inorganic arsenic to methylated arsenic species. Furthermore, this lichen-induced methylation occurs with some delay, possibly as a reaction to the transplantation of the lichen itself, and therefore transplanted lichens are only suitable for long-term biomonitoring studies. For tree bark only total arsenic concentration data could be generated since speciation analysis failed due to too low an initial total arsenic concentrations. 相似文献
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A. P. Marques M. C. Freitas M. A. Reis H. Th. Wolterbeek T. Verburg J. J. M. De Goeij 《Journal of Atmospheric Chemistry》2004,49(1-3):211-222
Transplants of the epiphytic lichen Parmelia sulcata were suspended in nylon bags in a special device allowing a fixed orientation of the lichen towards the wind direction, viz. facing the wind (F orientation) or shielded from the wind by its substrate (T orientation). The F- and T-orientation data were mutually compared and also with reference values (= time zero values of the transplants). The data were analysed via Monte Carlo added target transformation factor analysis (MCATTFA) to get information on possible emission-source profiles and their contributions to total-element levels in transplants, in F- and T-orientations. Both orientations did not differ for Na, Mg, P, Cl, K, Fe, Co, Ni, Ga, Se, Br, Sr, Ba, La, Nd, Sm, Lu and Ta, but showed some time-related differences for Cr and Zn. For the remaining elements the data presents a high variability. Under the conditions of the experiment, F- and T-oriented transplants generally did not result in differences in source profiles reflected, nor in differences in source contributions to element levels in the transplants. 相似文献
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