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1.
Landscape Ecology - Variability in temperature and snow cover are characteristics of high-latitude environments that impose significant pressures on overwintering species. To cope with increased...  相似文献   

2.
Summary

This review aims to describe the nature of effective microorganisms (EM) and how EM influence the growth, yield, quality, and protection of vegetable plants. EM comprise a mixture of live natural cultures of microorganisms isolated from fertile soils that are used to improve crop production. EM technology was developed over 40 years ago by Dr. Tero Higa in Japan. How EM act and interact in the soil-plant environment to suppress plant pathogens and disease, to conserve energy, to solubilise soil minerals, to aid the balance and ecology of soil microbes, and to improve photosynthetic efficiency and biological nitrogen fixation are described. In 70% of published studies, it was concluded that EM had a positive effect on the growth of vegetables, while, in the other 30%, they had no significant influence. In this investigation, among 22 reports on the effects of EM on the yields of vegetables, 84% were positive, 4% were negative, and 12% showed no significant influence. It is concluded that EM can improve the quality and yield of vegetables by reducing the incidence of pests and diseases, and by protecting against weeds, thereby contributing to sustainable agriculture.  相似文献   

3.

Purpose

Treelines and forest lines (TFLs) have received growing interest in recent decades, due to their potential role as indicators of climate change. However, the understanding of TFL dynamics is challenged by the complex interactions of factors that control TFLs. The review aims to provide an overview over the trends in the elevational dynamics of TFLs in Norway since the beginning of the 20th century, to identify main challenges to explain temporal and spatial patterns in TFL dynamics, and to identify important domains for future research.

Method

A systematic search was performed using international and Norwegian search engines for peer-reviewed articles, scientific reports, and MA and PhD theses concerning TFL changes.

Results

Most articles indicate TFL rise, but with high variability. Single factors that have an impact on TFL dynamics are well understood, but knowledge gaps exist with regard to interactions and feedbacks, especially those leading to distributional time lags. Extracting the most relevant factors for TFL changes, especially with regard to climate versus land-use changes, requires more research.

Conclusions

Existing data on TFL dynamics provide a broad overview of past and current changes, but estimations of reliable TFL changes for Norway as a whole is impossible. The main challenges in future empirically-based predictions of TFLs are to understand causes of time lags, separate effects of contemporary processes, and make progress on the impacts of feedback and interactions. Remapping needs to be continued, but combined with both the establishment of representative TFL monitoring sites and field experiments.
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4.
A working group within the European Union funded COST Action E12, “Urban Forests and Trees”, carried out a survey between 1999 and 2001 to study current tree establishment practice in European towns and cities. An extensive questionnaire requesting information on the urban area, selection of tree species, establishment and aftercare practices and the main damaging factors was sent to tree professionals in urban areas in each of 17 countries.Indicators such as the relationship between the urban population and the number of street trees were used to compare urban areas. While most central European cities have a ratio of 50–80 street trees per 1000 inhabitants, the tree density was as low as 20 street trees per 1000 inhabitants for Nice. Often only a few species are planted and this may give cause for concern, since species diversity is considered an important factor in increasing the resilience of the urban tree population to abiotic and biotic stresses.The planting of larger street trees of 20–30 cm circumference, usually with hessian-wrapped rootballs, is becoming increasingly common practice. However, some countries report the use of mostly bare-rooted stock of much smaller trees (less than 12 cm circumference). Establishment costs for street trees range from less than 200 Euro to over 1500 Euro each. Poor site conditions, and impacts such as utility trenching are considered to be major restrictions to healthy tree life. Vandalism affects up to 30%of newly planted street trees in some towns and cities.Overall, the survey reveals large differences in tree establishment and management practices among European cities. There is a need to provide urban tree managers with guidance on good practice for tree selection and establishment based on empirical information. The survey was a first step towards collecting the necessary urban forest information from across Europe.  相似文献   

5.
A plasmid containing target DNA and a standard curve for real-time quantitative PCR of the coldinduced Cor3 gene of Volvariella volvacea were constructed. These will provide the basis for further research on Cor3 gene expression at low temperature, and ultimately for assigning a role for the gene in the low temperature autolysis of V. volvacea.  相似文献   

6.
Summary

Modern drying technology provides the opportunity to obtain dried fruits with high concentrations of bioactive compounds. Such products may also be fortified with functional ingredients. The adoption of dried fruit as a carrier of functional ingredients for consumers is indispensable to launch this kind of product successfully on the market. Thus, the aim of this study was to collect data on consumer perceptions and interests in dried fruits (plain or fortified) through a questionnaire distributed on the Internet to 1,092 Dutch, French, and Polish respondents. In this quantitative study, the respondents were first asked to rank statements about a product with different positive influences on human health. Products which lowered the risk of cancer or heart diseases were mainly of interest to Polish and Dutch respondents, whereas French consumers emphasised the prevention of intestinal problems. Furthermore, we checked the level of consumer interest in dried fruits enriched with a particular functional ingredient (e.g., anti-oxidants, natural fruit sugars, or prebiotics). Products with anti-oxidants seemed to be the most promising in all three countries investigated. Among five different forms of product (i.e., candy, fruit teas, cereals, bars, or cookies) in which dried fruit could be incorporated, cereals were selected by approx. 33% of all respondents as the best product to which a functional dried fruit could be added. In summary, dried fruits can be adopted as carriers of functional ingredients, especially when promoted as a source of anti-oxidants.  相似文献   

7.
Abstract

It is generally thought that olives (Olea europaea) require several days (over 80 days) of chilling temperatures (7.2°C) for flower induction; minimum nighttime temperatures of 2-4°C and maximum daytime temperature of 15.5-19°C are considered optimum for flower and fruit production. Environmental chamber studies were conducted on potted olive trees for the purpose of defining flowering conditions for ‘Arbequina’. We repeatedly observed that good flower and fruit production in ‘Arbequina’ can be achieved even when the plants are not subjected to “chilling” temperatures or any chilling criteria that had previously been described necessary for flower and fruit production in olives. This phenomenon could be of great practical value because the results obtained can be exploited to cultivate olives in subtropical climates (e.g., southern and coastal Texas) where typical “chilling” temperatures are not commonly observed for prolonged periods of time.  相似文献   

8.
A flavor-related enzyme from Toona sinensis (TS), ?-glutamyl-transpeptidase (GGT), was purified 40.67-fold with 13.40% recovery using ammonium sulfate precipitation, dialysis and gel filtration chromatography. Gel filtration chromatography and sodium dodecyl sulfate acryl amide gel electrophoresis (SDS-PAGE) revealed that GGT was a heterodimer with a molecular weight of 90 kDa, and the molecular size of its two subunits was 26 kDa and 64 kDa, respectively. The apparent Km and Vmax of GGT were 3.623 μmol/mL and 2.831 μmol/mL/min of protein, respectively. The optimum reaction temperature was 60°C, while the optimum pH was 7.0. GGT can tolerate temperatures of 70°C for a short time and can keep stable activity at 60°C for more than 2 hours. The effect of metal ions on GGT activity showed that Cu2+ and Zn2+ had strong inhibition, while Fe3+ had strong activation, and other metal ions had only a slight effect. LC-MS analysis indicated that GGT catalyzed (S, S)-γ-glutamyl-(cis-S-1-propenyl)-thioglycine, a flavor precursor found in TS, to release glutamic acid moiety.  相似文献   

9.
AIM: Some epidemiologic evidences suggest an association between type 2 diabetes mellitus (T2DM) and Alzheimer disease (AD). The present study was designed to explore the common pathogenesis in these two diseases by comparing the pathological changes in pancreas and hippocampus, the activity of glucogen synthase kinase 3β (GSK-3β) and protein phosphatase 2A (PP2A) in T2DM rats with those in AD rats. METHODS: The SD rats were fed with high glucose, high fat and high protein for 8 weeks, and then injected with streptozocin (STZ) to establish the T2DM models. The model of AD was made by injection of STZ in hippocampus. The levels of hyperphosphorylated tau protein and β-amyloid protein (Aβ) in hippocampus and pancreas were analyzed by Western blotting and immunochemistry. The activities of GSK-3β and PP2A were determined by using γ-32P-ATP and the specific peptide substrate. RESULTS: In hippocampus of T2DM rats, the tau protein was hyperphosphorylated, the Aβ level was raised, the activity of PP2A was increased and the activity of GSK-3β was decreased, which were also observed in the hippocampus of AD rats. In the AD rats, the Aβ level in pancreas was found to rise, the activity of PP2A decreased and the activity of GSK-3β increased, which were similar to the changes in pancreas of T2DM rats. However, tau protein was not detected in the pancreas of both groups. CONCLUSION: These findings suggest that there are some common pathological changes between T2DM and AD. The hyperphosohorylation of tau protein in hippocampus, the raised Aβ level in hippocampus and pancreas, as well as the corresponding activities of PP2A and GSK-3β may contribute to the pathogenesis in the development of T2DM and AD.  相似文献   

10.
Summary

Postharvest heat treatments have been used for many years as alternatives to chemical control of fungal diseases and insect infestation of fruits and vegetables. In this study, the effects of a new hot-water brushing (HWB) treatment on the resistance of red grapefruit (C. paradisi cv. Star Ruby) to green mould decay caused by Penicillium digitatum (Pers.: Fr.) Sacc. and on the development of chilling injury (CI) symptoms during cold storage were examined. The HWB treatment comprises rinsing hot water on the fruits as they move along a belt of brush rollers. A twenty second HWB treatment at 59 or 62° reduced decay, after arti®cial inoculation of wounded fruit, by 52 or 70%, respectively, compared with control unwashed fruit, whereas rinsing and brushing the fruit with tap water (~20°) or with hot water at 53 or 56°, were ineffective. HWB treatments applied 1–3 d prior to inoculation were most effective in enhancing the disease resistance of fruit, but were much less effective when the fruit were inoculated on the same day or 7.d later. HWB treatments at 59 or 62° for 20.s also significantly reduced the CI index and the percentage of fruit displaying CI symptoms by 42 and 58%, respectively, after six weeks’ storage at 2° and an additional week at 20°. Furthermore, HWB treatments cleaned the fruit and improved its general appearance without causing any surface damage, and did not influence fruit weight loss, percentage of total soluble solids (TSS) in the juice, juice acidity or fruit colour.  相似文献   

11.
Regional variation in nitrogen (N) deposition increases plant productivity and decreases species diversity, but landscape- or local -scale influences on N deposition are less well-known. Using ion-exchange resin, we measured variation of N deposition and soil N availability within Elk Island National Park in the ecotone between grassland and boreal forest in western Canada. The park receives regionally high amounts of atmospheric N deposition (22 kg ha−1 yr−1). N deposition was on average higher ton clay-rich luvisols than on brunisols, and areas burned 1–15 years previously received more atmospheric N than unburned sites. We suggest that the effects of previous fires and soil type on deposition rate act through differences in canopy structure. The magnitude of these effects varied with the presence of ungulate grazers (bison, moose, elk) and vegetation type (forest, shrubland, grassland). Available soil N (ammonium and nitrate) was higher in burned than unburned sites in the absence of grazing, suggesting an effect of deposition. On grazed sites, differences between fire treatments were small, presumably because the removal of biomass by grazers reduced the effect of fire. Aspen invades native grassland in this region, and our results suggest that fire without grazing might reinforce the expansion of forest into grassland facilitated by N deposition.  相似文献   

12.

Context

Mountainous landscapes are characterized by strong spatial heterogeneity, leading to increasing geographical isolation and decreasing area with elevation. Consequently, the colonization rate decreases from the low to high elevation zone, while the extinction rate shows the opposite.

Objectives

Due to such changes, we test whether (1) species occur at a declining number of sites (mountains) and have a less positive abundance–occupancy relationship (AOR) in a higher elevation zone; (2) a lower proportion of rare large-bodied species (less resistant to extinction) and a more positive abundance–body mass relationship (ABR) emerge in a higher elevation zone.

Methods

Using the data of small mammals from 20 elevational gradients in the Mountainous Region of Southwest China, we compared the AORs and ABRs among the low, middle and high elevation zones. The AOR and ABR were fitted with linear and polynomial regression models. We compared endemic ratios among the different elevation zones.

Results

The AOR was best characterized by a linear model and positive in all elevation zones. Its slope decreased from the low to high elevation zone. The quadratic model performed the best in fitting the ABR in each zone. When fitted with linear models, both the R2 and slope of the ABR increased towards the high elevation zone. The endemic ratios were significantly higher in the middle and high elevation zones.

Conclusions

Both the AOR and ABR in mountainous landscapes are strongly elevation-dependent. The increasing geographical isolation and decreasing area with elevation can have a high impact on macroecological patterns and processes.
  相似文献   

13.
An understanding of how and where a landscape can be improved with green infrastructure is important for the development of land-use policies. However, it is still a big challenge to manage landscapes due to a lack of condition-based diagnosis and consistent conflicts with social–economic interests. The purpose of this study is to identify the thresholds of landscape change and to explore new reference lines of policy decision-making for balancing social–economic development and green infrastructure management. Five different landscape types and their thresholds of landscape change were identified using parametric and piecewise linear models in the district of Haidian, Beijing, PR China, and their changes and social–economic drivers were analyzed with principal component analysis and a stepwise linear regression model for the time period 1991–2010. It is shown that different thresholds of different landscapes do exist and can be identified by the area of their key elements of green infrastructure. Integrating these thresholds into a social–economic context, it is shown where and how social–economic variables can be manipulated quantitatively to achieve development targets with respect to green infrastructure in individual towns and the entire district. Green infrastructure can be managed by changing just a small proportion of social–economic investment. This paper provides a useful tool to achieve a sustainable development by balancing green infrastructure with social–economic interests.  相似文献   

14.
Domestic gardens constitute important refuges for biodiversity. However, their typical small size mismatches with the larger scales at which species procure resources from urban areas. Consequently, they lack the capacity to enhance biodiversity at these scales. This could be addressed by aggregating garden resources (e.g. vegetation) and increasing garden connectivity. Specifically, this could involve neighbouring householders removing brick walls and fences that segregate gardens and collectively planting vegetation across garden boundaries. Nevertheless, insufficient research has explored 1) how hard surfacing gardens influences native/non-native vegetation presence, which could influence this action’s effectiveness 2) the number of householders willing to undertake such action 3) reasons for unwillingness and how this could be resolved. These research gaps were addressed using an online householder questionnaire distributed weekly to the UK ‘followers’ of four Facebook pages from January to December 2014. From a total of 276 respondents, 220 (84 %) had gardens with hard surface and this had a significant negative association with native vegetation presence. Only 7 (3%) presently collectively planted vegetation, but 152 (58 %) expressed future willingness. Desires to retain garden control and privacy predominantly underpinned unwillingness. In order to increase the effectiveness and prevalence of collectively planted vegetation, more stringent planning policy is required to restrict hard surfaced gardens. Moreover, desires for garden control and privacy need to be accommodated. This could be principally achieved by 1) communicating that little control would be lost as a result of this action 2) segregating gardens with hedges, which benefit biodiversity and simultaneously provide privacy.  相似文献   

15.
A 531 bp fragment of a putative mitochondrial intermediate peptidase (mip) gene from Lentinula edodes was amplified by PCR using a pair of degenerate primers designed according to conserved sequences of mip genes reported in other Basidiomycetes. Alignment analysis revealed that this putative partial mip gene from L. edodes exhibited high homology with corresponding segments of mip genes from the other Basidiomycetes. Since the gene encoding MIP appears to be very closely linked with the A type mating gene of Basidiomycetes, identification of mip may prove a useful tool for locating and cloning the A type mating gene in L. edodes and other edible fungi.  相似文献   

16.
Crop yield forecasting has progressed clearly in the past years, mainly due to the growing demand for modelling. In the present research, considering the Mediterranean vocation for the olive cultivation, olive yield forecasting modelling was analysed, to understand the principal relationships between olive tree production and climate features in a large southern Italy area. The simulation of olive yield has practical application in different price formation activities: in management of cropping systems, formation of stocks, commercialization, making of agricultural policies and zoning. Both meteorological and biological variables were considered, pollen indexes were constructed from daily pollen concentrations evaluated by use of aerobiological methodology. The monitored pollen quantities should be considered as a Proxy variable of the olive orchards located around the volumetric pollen traps, even if the final harvest could be highly dependent on local summer meteorological conditions. The model carried out by use of Panel data analysis has demonstrated a great interpretative capacity, considering contemporary meteorological and biological variables (pollen monitored with volumetric traps). The aggregation of historical data (1999–2008) with cross-section data (10 different pollen monitoring stations) permitted to investigate the variability information related to temporal and geographical dimensions. The entire volume of pollen grains emitted during flowering was redundant to investigate the future fruit formation while the specific and concentrated mass of pollen grains during the days before full flowering was related positively with the final production. The statistical technique utilized permitted to obtain interpretative results common to different geographical areas and not limited by local meteorological conditions.  相似文献   

17.
We evaluated the accuracy and efficiency of airborne (ALS), terrestrial (TLS) and mobile laser-scanning (MLS) methods that can be utilized in urban tree mapping and monitoring. In the field, 438 urban trees located in park and forested environments were measured and mapped from our study area located in Seurasaari, Helsinki, Finland. A field reference was collected, using a tree map created manually from TLS data. The tree detection rate and location accuracy were evaluated, using automatic or semiautomatic ALS individual tree detection (ALSITDauto or ALSITDvisual) and manual or automatic measurements of TLS and MLS (TLSauto, MLSauto, MLSmanual, MLSsemi). Our results showed that the best methods for tree detection were TLSauto and MLSmanual, which detected 73.29% and 79.22% of the reference trees, respectively. The location accuracies (RMSE) varied between 0.44 m and 1.57 m; the methods listed from the most accurate to most inaccurate were MLSsemi, TLSauto, MLSmanual, MLSauto, ALSITDauto and ALSITDvisual. We conclude that the accuracies of TLS and ALS were applicable for operational urban tree mapping in heterogeneous park forests. MLSmanual shows high potential but manual measurements are not feasible in operational tree mapping. Challenges that should be solved in further studies include ALSITDauto oversegmentation as well as MLSauto processing methodologies and data collection for tree detection.  相似文献   

18.
The world is changing rapidly, challenging the sustainability of landscapes and the resources and ecosystem services they provide to people and to plants and animals. Changes in land use and climate will alter the structure and composition of landscapes, and landscape functions may also be disrupted if the changes drive systems past thresholds into novel, no-analog configurations. Although landscapes will persist in some form, it is unlikely that they will provide the same values to people or habitat for wildlife that are the focus of current sustainability efforts. Tradeoffs among services to people or resources for wildlife will be inevitable. For the concept of sustainability to be relevant under these conditions, we must ask, “Sustainability of what, for whom?” Landscapes cannot be all things to all people (or organisms). Decisions about how to balance competing needs and goals and set priorities requires an understanding of landscape structure, function, and change—the foundation elements of landscape ecology.  相似文献   

19.
20.
We argue for the landscape ecology community to adopt the study of poverty and the ecology of landscapes as a Grand Challenge Topic. We present five areas of possible research foci that we believe that landscape ecologists can join with other social and environmental scientists to increase scientific understanding of this pressing issue: (1) scale and poverty; (2) landscape structure and human well-being; (3) social and ecological processes linked to spatial patterns in landscapes; (4) conservation and poverty, and (5) applying the landscape ecologist’s toolkit. A brief set of recommendations for landscape ecologists is also presented. These include the need to utilize broad frameworks that integrate social and ecological variables, build capacity to do this kind of work through the development of strong collaborations of researchers in developed and developing countries, create databases in international locations where extreme poverty exists, and create a new generation of researchers capable of addressing this pressing social and environmental issue.  相似文献   

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