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111.
The loss of connectivity of forest landscapes is seriously hindering dispersal of many forest-dwelling species, which may
be critical for their viability and conservation. In this context, explicitly incorporating connectivity considerations is
an important challenge in current forest planning and management, but as yet there is a lack of operative methods for appropriate
decision making in this respect. We describe a new methodology based on graph structures and a habitat availability index
(integral index of connectivity) that integrates forest attributes (like habitat quality) and network connectivity in a single
measure. We apply this methodology to examine the connectivity of the highly fragmented habitat of capercaillie (Tetrao urogallus) in Catalonia (NE Spain), where the threatened status of this forest bird species calls for landscape-level forest planning
solutions. We analyse data on the distribution of capercaillie forest habitat at 1 km spatial resolution obtained from the
recent Catalan Breeding Bird Atlas. We determine the functionally connected regions existing within its habitat distribution
and identify the forest habitat areas that are more important for the maintenance of overall landscape connectivity for this
species. Based on these results, we provide recommendations on certain critical public forests where management oriented to
the conservation of capercaillie habitat is more necessary. These results highlight the potential and practical interest of
the proposed methodology for successfully integrating landscape connectivity in broad scale forest planning. 相似文献
112.
Vicente Rozas José Miguel Olano Lucía DeSoto David Bartolomé 《Annals of Forest Science》2008,65(8):809-809
113.
The impact of extrusion on physical and sensory properties and on the in vitro bile acid (BA) binding was examined for N979 and Jim oat (Avena sativa) lines with 8.1 and 4.8% β‐glucan, respectively. Based on hardness and edibility of products made from Jim oats, moisture concentrations of 16–25% and temperatures of 165–180°C were selected for N979 extrusion. Jim‐based cereal had a significantly greater (P < 0.05) expansion ratio than did N979‐based cereal at most moistures. N979 cereal was browner, but not harder, than Jim cereal. Extruded products from N979 and Jim oats had 5.29–5.99% and 3.38–3.94% β‐glucan, respectively. Changing extrusion temperature or moisture content did not affect β‐glucan concentration in the products. N979 cereal made at 165°C and 16% moisture had greater BA binding than at other conditions, and had crunchiness comparable to cereals made at other conditions. BA binding of Cheerios brand breakfast cereal was close to that of N979 cereal made at 180°C and 18% moisture, but lower than cereals made at other conditions. Cereals made from Jim and N979 oats were browner, harder, coarser, and crunchier than Cheerios breakfast cereal. Proper processing and preparation techniques should be considered when producing extruded products from high β‐glucan oats. 相似文献
114.
Metalaxyl and tricyclazole are two fungicides widely used in Spain in vineyard and rice crops respectively. In this study an investigation has been made of the effect of three organic amendments [two commercial amendments, solid fertiormont (SF) and liquid fertiormont (LF), and a residue from the olive oil production industry, alperujo (OW)] on fungicide fate in soils. Changes in soil porosity on amendment were studied by mercury intrusion porosimetry, sorption-desorption studies were performed by the batch equilibration method, dissipation of metalaxyl and tricyclazole in the soil was studied at - 33 kPa moisture content and 20 degrees C and leaching was studied in hand-packed soil columns. Amendments with SF and LF reduced soil porosity, while OW increased porosity through an increase in pore volume in the highest range studied. Tricyclazole sorbed to soils to a much higher extent than metalaxyl. With some exceptions, sorption of both fungicides increased on amendment, especially in the case of SF-amended soils, which rendered the highest K(oc) values. In soils amended with the liquid amendment LF, sorption either remained unaffected or decreased, and this decrease was much higher in the case of metalaxyl and a soil with 70% clay. In this clay soil, amendment with OW, of very high soluble organic matter content, also decreased metalaxyl sorption. Tricyclazole is more persistent in soil than metalaxyl, and both fungicides were found to be more persistent in amended soils than in unamended soils. Leaching of metalaxyl and tricyclazole in soil columns was inversely related to sorption capacity. The low recoveries of tricyclazole in leachates and in soil columns when compared with metalaxyl, a less persistent fungicide, were attributed to diffusion into micropores and to increase in sorption with residence time in the soil, both processes favoured by the low mobility of tricyclazole. 相似文献
115.
Tetranychus urticae Koch has recently developed resistance to chlorfenapyr in Australia and Japan, but no attempt has yet been made to describe the biochemical mechanisms involved in chlorfenapyr resistance. In this study a laboratory-selected chlorfenapyr-resistant strain was investigated. Resistance to chlorfenapyr was associated with a strong increase in esterase activity and P450 mono-oxygenase (MO) activity but a decrease in 3,3',5,5'-tetramethylbenzidine (TMBZ) peroxidation activity. Differences in esterase activities between susceptible and resistant strains increased with increasing carbon number of the aliphatic side-chain of the nitrophenol substrate. A 4.4-fold increase in the O-deethylation of 7-ethoxy-4-trifluoromethyl coumarin (7-EFC) mediated by P450 MOs was detected. Remarkably, the resistant strain showed only half of the total TMBZ peroxidation activity found in the susceptible strain. The activity of these enzymes was further determined on different crosses and back-crosses of both strains. Results indicated that activities correlated with chlorfenapyr susceptibility and could be considered as biochemical markers. Esterase isozymes of both strains and their crosses were separated with isoelectric focusing (IEF) and visualised after activity staining. It was clear that two distinct zones of enhanced esterase activity were present in the chlorfenapyr-resistant strain (EST 11, pI = 4.88 and EST 16, pI = 4.71). EST 11 was identified with inhibitors as a carboxylesterase. The relative presence and intensity of these esterase zones changed in the different crosses and could be seen as a marker for chlorfenapyr resistance. Glutathione-S-transferase and glucose-6-phosphate dehydrogenase activities were not significantly different between strains. A twofold decrease in TMBZ peroxidase activity in the resistant strain could reflect decreased activation of chlorfenapyr. On the basis of these results the involvement of P450 MOs and esterases in the activation and detoxification of chlorfenapyr in T. urticae is challenged and discussed. 相似文献
116.
自2008年7月起,欧盟可能不会支持将甲醛列入<欧洲抗菌导则>(European Biocidal Directive,EBC)中.即使甲醛仍将得到使用许可,但许多孵化厂将研究无甲醛的消毒方法,因为众所周知甲醛是一种致癌性有害物. 本文所述的甲醛替代品有二种:一种是由戊二醛和季氨化合物(Quatemary Ammonia Compounds,QAC)组成的消毒剂,二是由稳定的过氧化氢和过乙酸组成的消毒剂. 相似文献
117.
Heike Kappes Kurt Jordaens Frederik Hendrickx Jean-Pierre Maelfait Luc Lens Thierry Backeljau 《Landscape Ecology》2009,24(5):685-697
Habitat fragmentation is a major cause for species loss, but its effect on invertebrates with low active dispersal power,
like terrestrial gastropods, has rarely been studied. Such species can not cross a hostile habitat matrix, for which the predictions
of island theory, such as positive relations between species richness and patch size, should apply. In order to test this
prediction, we studied gastropod species diversity by assessing gastropod assemblage characteristics from 35 sites in 19 fragments
of deciduous old-growth forests in the Lower Rhine Embayment, Germany. Assemblages differed between larger (≥700 ha) and smaller
forests (<400 ha), those of large forests held a higher percentage of forest species. Although α-diversity was similar between
the two forest size classes, small forests often comprised matrix species, resulting in a higher β-diversity. Edge effects
on the species richness of matrix species were noticeable up to 250 m into the forest. Hierarchical partitioning revealed
that distance to disturbances (external edge, internal edges like roads) explained most assemblage variables, whereas forest
size and woodland cover within a 1 km radius from the sites explained only a few assemblage variables. Densities of two forest-associated
species, Discus rotundatus and Arion fuscus, decreased with forest size. Yet, forest size was positively correlated with richness of typical forest species and densities
of Limax cinereoniger. The latter species seems to need forests of >1,000 ha, i.e., well above the size of most fragments. In conclusion, the prediction
is valid only for forest species. The response to fragmentation is species specific and seems to depend on habitat specialization
and macroclimatic conditions.
Jean-Pierre Maelfait: Deceased. 相似文献
118.
119.