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1.
Ryszkowski  L.  Bartoszewicz  A.  Kędziora  A. 《Landscape Ecology》1999,14(5):479-492
Long-term studies of the influence of biogeochemical barriers (shelterbelts and stretches of meadows) on water cycling and control of ground water pollution in an agricultural landscape have shown that more solar energy is used for evapotranspiration in shelterbelts than in cultivated fields or meadows. Therefore, annual water runoff from cultivated fields is about 170% higher than from coniferous forest, 60% higher than deciduous forest and 16% higher than meadows. The differences in evapotranspiration rates between shelterbelts and meadows increases when additional energy input for evapotranspiration is provided by transport of heat from cultivated fields to these habitats by advection. The average water percolation time through the unsaturated zone of soils varies by 100%. A shelterbelt, having a mixed species composition, more effectively screens the passage of chemical compounds dissolved in ground water than shelterbelts composed of one tree species. Peat soils have a very high cation exchange capacity which increases the efficiency of riparian meadows for the control of ground water pollution. Natural landscape features which assist in controlling matter cycles are of great importance for modifying chemical outputs from agricultural watersheds.  相似文献   

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Dispersal limitations contribute to shaping plant distribution patterns and thus are significant for biodiversity conservation and urban ecology. In fleshy-fruited plants, for example, any preference of frugivorous birds affects dispersal capacities of certain fruit species. We conducted a removal experiment with fruits of Ilex aquifolium, a species that is currently expanding its range margin in northern Europe in response to climate change. The species is also a popular ornamental tree and naturalization has been observed in many parts of its range. Fruits of native I. aquifolium and of three cultivars were offered to birds at the expanding range margin in urban habitats in eastern Denmark. The four fruit types were removed at different rates and red fruits were preferred over a yellow cultivar. Small fruit diameter was positively related to fruit removal, and removal was faster under tree canopies compared with open habitats. The preference for red cultivars compared with native I. aquifolium may contribute to naturalization and potential invasion of garden escapes. Preferential foraging under closed canopies indicates trees and shrubs as recruitment foci for fleshy-fruited plants in urban landscapes. The results should be included in urban forestry and planting of potentially invasive ornamental species.  相似文献   

4.
AIM:To observe the effects of high temperature on voltage - dependence of delayed rectifier K+ channel (Ik) in hypothalamus neurons. METHODS: The date recording from cell - attached patches of patch - clamp technique. RESULTS: With temperature raising, shift of voltage dependence may be mediated at different degree, while higher temperature might weaken and depressed. CONCLUSION: Shift of voltage dependence likely contribut- ed to the body fever and heatstroke.  相似文献   

5.
City edges have been associated with waste and wastelands for centuries. Refuse dumps have frequently been located at the outskirts of the city, and the metaphor of ‘wasteland’ has been used to depict landscapes at the urban fringe. In this paper, the relationship between actual waste dumps and metaphorical wastelands is brought forward to facilitate an analysis of landscape transformations at the city edge and to reveal the neglect of transient landscapes within spatial planning. In the first part of the paper the interactions between dumps and ‘wastelands’ at the city edge are discussed. In the second part, a case study at the edge of Malmö (in southern Sweden) is presented as an illustration of the transformative city edge and in particular the invisibility of this landscape in local planning. Major landscape transformations during the 20th century are examined along with representations of the area within spatial planning. The primary sources of information have been the archives of the local and regional waste management divisions, local planning documents and field studies. The case study illustrates how the present fringe landscape is constantly camouflaged by a green future; it is always about to be transformed, and therefore ignored. Consequently, an everyday landscape, with hazardous waste as well as places of great potential for recreation, has been disregarded for decades. The paper concludes with a discussion emphasising the importance to unveil such utopian representations, and the need to highlight the present day situation at the city edge.  相似文献   

6.
SUMMARY

Young coconut (Cocos nucifera L.) fruit collected 6–8 months after anthesis (MAA) contain a high volume of water [20% (w/w)] and can provide a refreshing drink. The present study investigated volatile organic compounds (VOCs), as aroma components, and physico-chemical changes in the liquid endosperm of young ‘Nam Hom’ coconut at two stages of maturity: the one-layer stage (6 MAA) and the two-layer stage (7.0–7.5 MAA) of the flesh. The liquid endosperm of coconut fruit becomes sweeter and more turbid late during maturation. Lauric acid (C12:0) and myristic acid (C14:0) were the main free fatty acids in the liquid endosperm of coconut. Short-chain fatty acid (C10–C12) concentrations increased slightly, and longer-chain fatty acid (C14–C18) concentrations declined when fruit matured from the one- to the two-layer stage of flesh. Solvent extractions showed a 1.4-fold increase in the total concentration of VOCs in the liquid endosperm during fruit development. This was related to a major increase in squalene and sterols, to 21.7% (w/w) of the total VOC and non-volatile organic compounds, whereas the concentrations of terpenes and esters remained stable. Although a series of alkanes existed in the liquid endosperm of coconut, the main aroma components were 2-methyl-1-butyl acetate and terpenes such as D-limonene, α-pinene, and 3-carene. We conclude that, when coconut fruit developed from the one- to the two-layered flesh stage, the liquid endosperm not only became sweeter and contained higher concentrations of aroma volatile and non-volatile components, but also became oily and less translucent.  相似文献   

7.

Context

The provision of multiple ecosystem services (ES) within a landscape is commonly referred to as landscape multifunctionality. Modifying landscapes to increase multifunctionality and reduce trade-offs with concurrent services bears the potential to enhance sustainability in human-dominated landscapes. Assessing landscape multifunctionality is thus crucial for land management and planning, but lack of a clear definition and operationalization of multifunctionality impedes comparisons of different study results.

Objectives

We want to address how elements of the study design affect results of multifunctionality assessments. Furthermore, we want to quantify future multifunctionality in the European Union (EU) and indicate the role of land use change and land use diversity on multifunctionality.

Methods

We analyzed diverging scenarios depicting land use change in the EU between 2000 and 2040 for their effects on landscape multifunctionality. We tested different multifunctionality indicators at various spatial scales based on the modelling of 12 ES and biodiversity indicators.

Results

Particularly the analysis scale determines the interpretation of landscape multifunctionality. Coldspots identified by different indicators are in higher agreement than hotspots. We could not confirm links between land use diversity and landscape multifunctionality. While, at EU scale, multifunctionality slightly increases in future scenarios, agricultural intensification and (peri-)urban growth pose large threats to multifunctional landscapes.

Conclusions

The choice of indicator and analysis scale strongly determine possible interpretations of the results. Rather than focusing on the impacts of land use change on multifunctionality, it is recommended to base land use policy on the impacts of location-specific change on ES supply and demands.
  相似文献   

8.
The Hexa-Hives illustrate how an outdoor live installation (landscaped garden installation) can serve as incentive for inter-species encounters and at the same time challenge the paradigm of conventional beekeeping. The Hexa-Hive is an experimental hive, designed to both host honeybees and serve as outdoor furniture for humans. Since 2012, the Hexa-Hive has been a semi-permanent installation in Kaisaniemi Botanic Garden of Helsinki.A further development, the Hexa-Hive Village was first installed at the campus of Aalto University, in Otaniemi, Finland in 2013. Launched as artistic intervention, the Hexa-Hive village became a landscaped area hosting honeybees and inviting people to hang out.In 2014, a further development - the installation “Hexa-Hive Village with Airstrip for Bees” - was exhibited as part of the art exhibition “Semi-Wild Gardens” at Kouvola city art museum and in 2016, the installation was placed in Tarja Halonen Park, a public area in the centre of Helsinki.The article explores the effects of the installation assessed via a questionnaire. The findings include the emergence of a “garden quality” around the “Hexa-Hive”, the increase of local faunal and floral diversity and the notion of wilderness in the city. The concept of urban acupuncture and the mental and psychological value of public gardens for humans are described as features of the installation.The Hexa-Hive is part of Melliferopolis and was launched in Helsinki in 2012. The activities comprise exhibitions, workshops, installations and lectures.www.melliferopolis.net  相似文献   

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10.

Context

Policy decisions form a major driver of land use change, with important implications for socially and environmentally susceptible regions. It is well known that there can be major unintended consequences, especially where policies are not tailored to regionally specific contexts.

Objectives

In this paper we assess the implications of 60 years of agricultural policies on soil erosion prevention (SEP) by vegetation, an essential regulating ecosystem service in Mediterranean Europe.

Methods

To assess these implications we produced and analysed a time series of land cover/use and environmental conditions datasets (from 1951 to 2012) in relation to changing agricultural policies for a specific region in the southern Portugal. A set of indicators related to SEP allowed us to identify that land use intensification as increased soil erosion in the last 60 years.

Results

Particularly in the last 35 years, as a consequence of headage payments for cattle, the agricultural policy had a significant effect in the density and renewal of the tree cover, resulting in drastic effects for the provision of the SEP service. These are more significant after 1986, coinciding with the implementation of several Common Agricultural Policy instruments focused on increasing the modernization and productivity capacity of farm systems.

Conclusions

The results show some unintended effects of agricultural policy mechanisms on ecosystem service provision and highlight the need for context-based policies, tailored to the environmental constrains and potentials of each region.
  相似文献   

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12.
Yu  Xiaoyu  Liu  Yue  Zhang  Zhonghao  Xiao  Rui 《Landscape Ecology》2021,36(9):2743-2762
Landscape Ecology - The building landscape greatly affects the urban heat island (UHI), especially in three-dimensional (3D) space, by changing the energy flow between the land surface, the...  相似文献   

13.
Landscape Ecology - Linking spatial pattern and process is a difficult task in landscape ecology because spatial patterns of populations result from complex factors such as individual traits, the...  相似文献   

14.
Summary

The apple rootstocks M.9, M.26, and MM.106 were evaluated for their efficiency in bringing ‘Discovery’ apple trees into production. The experiment, carried out over a ten- year period compared two planting densities at 1666 and 3333 trees per ha. Tree vigour differences between rootstocks were measured in term of trunk growth, tree volume, weight of branches pruned off and final weight of the above-ground parts of the trees. Fruit production is presented both as total yield and as the weight of first class fruit. Fruit colour development is also shown. Cropping efficiency is calculated and presented in relation to the different vigour measurements. The results confirm that ‘Discovery’ is slow to come into production. M.9 was the most productive rootstock, but due to vigour differences MM.106 gave the same yields per tree, although the latter had the lower yield efficiency. M.26 performed poorly; its vigour was similar to M.9 but it produced the lowest yields.  相似文献   

15.
In order to study the effect of nitrogen spray at different times on color and yield parameters of grape cv. Pykany, an experiment was carried out in factorial based on randomized complete block design with four replications in Khalil Abad County in 2015. The treatments included three concentrations of nitrogen (0, 5 and 10?ppm) and three spray times (Late April, before bloom stage, and after pollination and fruit set stage). Color parameters such as brightness rate (L), redness (a) and yellowness (b), chroma, hue angle and browning index were evaluated in this experiment. The results of variance analysis and means comparison showed that the effect of treatment containing spray at concentration of 10?ppm on yield was significant at 1%. There were not significant differences among treatments of urea concentrations and spray times on L and b but different concentrations of urea had significant effect on a* at the level of 1%, so that the highest amount of significant difference was due to the treatment of urea spray at the concentration of 10?ppm and the lowest amount was due to the control treatment. Furthermore, the interaction effect of concentration and different times of nitrogen application on color intensity index was significant at the level of 5%. Based on the results, the effect of different concentrations of urea spray on hue angle was significant at 1% so that the highest level of significant difference was due to the concentration of 10?ppm and the lowest was related to control treatment.  相似文献   

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17.

Background

Fungal pathogens like Fusarium graminearum can cause severe yield losses and mycotoxin contamination of food and feed worldwide. We recently showed its ability to systemically colonize wheat via root infection. However, the molecular response of wheat to Fusarium root rot (FRR) infection and systemic spread is still unknown. As a molecular camera, mass spectrometry (MS) imaging combines label-free and multiplex metabolite profiling with histopathology.

Results

Atmospheric-pressure (AP)-SMALDI-MS imaging was combined with optical microscopy to study wheat-F. graminearum interaction at the root–shoot junction, which is a crucial line of defense against a pathogen that can invade all distal plant parts. To scope the functional, temporal and local aspects of FRR disease spread, metabolic changes were simultaneous visualized in diseased and healthy stem bases of the resistant cultivar Florence-Aurore at 10, 14 and 21 days after root inoculation. Histological information was used to identify disease relevant tissues and to assist the interpretation of molecular images. Detected mycotoxin compounds secreted by F. graminearum showed a route of stem infection that was consistent with observations made by microscopy. The outer epidermis and vasculature of leaf sheath were, at different disease stages, identified as prominent sites of pathogen migration and wheat protection. Wheat metabolites mapped to these relatively small tissues indicated cell wall strengthening and antifungal activity as direct defenses as well as conservation in the wheat reactions to F. graminearum diseases that affect different plant organs.

Conclusions

AP-SMALDI-MS imaging at high spatial resolution is a versatile technique that can be applied to basic and applied aspects of agricultural research. Combining the technology with optical microscopy was found to be a powerful tool to gain in-depth information on almost unknown crop disease. Moreover, the approach allowed studying metabolism at the host–pathogen interface. The results provide important hints to an understanding of the complex spatio-temporal organization of plant resistance. Defense-on-demand responses to pathogen ingress were found, which provide opportunities for future research towards an improved resistance that does not negatively impact yield development in the field by saving plant resources and, moreover, may control different Fusarium diseases.
  相似文献   

18.
19.
When apples which develop low temperature breakdown (LTB) at 32° F. are moved from 32° F. to 65° F. for 3 to 5 days at about the 7th to 8th week of storage, they subsequently develop within a given period of storage less LTB than apples kept at 32° F. continuously.

The respiration of apples susceptible to LTB increases steadily during storage at 32° F. If these apples are warmed to 65° F. during the period of exposure to 32° F., the subsequent rate of respiration at 32° F. is lower than before warming, and continues at a lower rate than for apples kept at 32° F. continuously.

If the apples are moved to 38° F., without an intermediate treatment at 65° F., the rate of respiration is higher than for apples at 38° F. continuously, and this higher rate persists.

If there is an intermediate wanning period at 65° F., the respiration of apples moved from 32° to 38° F. is of the same order as that for apples kept at 38° F. continuously.

The respiratory quotient of apples at 32° F. or at 38° F., which is indicative of the type of respiratory activity, is typical for the temperature at which it is measured, and is not affected by the warming treatment. The effects of wanning on both the incidence of LTB and respiration are similar for apples stored in air and in 2% oxygen: 98% nitrogen.  相似文献   

20.
A trial on ‘Fuji’ apples at the Grove Research Station in southern Tasmania during the 1991/92 season studied the thinning effect and interactions between ethephon and benzyladenine (BA) when BA was applied as a secondary thinner after a full bloom (FB) application of ethephon. The spray treatments were a factorial combination of eight application times of BA (11,13,15,17,19, 21, 23 or 25 days after full bloom (AFB)) with ten concentrations (20,40,60,80,100,120,140,160,180 or 200 mg I“1). An unsprayed control and an ethephon control were included. Target thinning results were achieved 19- 23 d AFB with concentrations of 140-160 mg I“1. A corollary of this successful thinning was an increase in fruit weight and size. Return bloom was improved significantly where thinning was successful. There was no effect on fruit firmness, soluble solids or lateral branching. Drawbacks were an increase in the incidence of russet and a reduction in pip number at the optimum thinning times and concentrations.  相似文献   

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