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排序方式: 共有291条查询结果,搜索用时 15 毫秒
1.
Stanislav Torma Jozef Vilček Stanislav Kužel Anna Martensson 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2018,68(4):358-366
With increasing demand for sustainable production, the need to effectively utilise site-based resources increases. One such resource is the remaining crop residues, both above and below ground, after harvest. In order to assess the magnitude of this resource, this study determined the plant nutrient contribution of residues from 17 different crops in seven different regions of Slovakia over a nine-year period. The soil profile 0.0–0.3?m was taken into account at belowground residues sampling. The results showed that winter rape, mustard, corn maize, triticale, winter rye with straw and sunflower left the most residues, exceeding 8 tons of dry biomass per hectare. Root crops (sugar beet, potatoes) and peas left less than 3 tons of residual dry biomass per hectare. Using these data, the nutrient potential coefficient, i.e. the amount of nutrients left by production of one ton of the main product was calculated by polynomial regression. With these coefficients and the known yield of a given crop, it was possible to calculate how much nitrogen, phosphorus and potassium each crop leaves in the soil after harvest. It was found that the amount of nitrogen left ranged from 20 to 132?kg, phosphorus from 2 to 24?kg and potassium from 13 to 218?kg per hectare. This has to be taken into account when calculating the fertiliser requirement of the subsequent crop in order to achieve better resource utilisation, thereby reducing the risk of eutrophication and improving farm profits by reducing expenditure on fertiliser. 相似文献
2.
Gediminas Brazaitis Kęstutis Pėtelis Remigijus Žalkauskas Olgirda Belova Darius Danusevičius Vitas Marozas Gintarė Narauskaitė 《European Journal of Forest Research》2014,133(5):857-869
We analyse the relationships between the main Cervidae [moose (Alces alces), red deer (Cervus elaphus) and roe deer (Capreolus capreolus)] species and a complex of environmental factors in an extensive fragmented landscape of Central Lithuania. The highest determining positive influence on moose density was the proportions of wet forest sites. In forest complexes with fewer proportions of wet sites, the most important factor was the total forest area. The proportion of shrub cover, upland and dense undergrowth area, and road density also has significant effect on moose density. The total area of forest complexes has the highest determining positive influence on red deer density. The highest density of red deer was calculated in large forest complexes (>2,745 ha) with a <17.6 % proportion of pine and <36.5 % of deciduous forests. Other significant factors were core area, road density and urbanization level. Forest edge density has the highest influence on the roe deer populations. The highest density of roe deer was recorded on forest areas with >51 m ha?1 of edges in wet forest (>25.4 %) dominating areas. The proportion of deciduous, coniferous mixed and pine forest, also shrub and density of edges also had significant effect. 相似文献
3.
Emin Zeki Başkent Ali İhsan Kadıoğulları 《Scandinavian Journal of Forest Research》2014,29(7):121-131
Decision support systems (DSSs) are indispensable tools in preparing a forest management plan for a better combination of multiple forest values. This study attempted to develop and explain a stand-based forest management DSS (Ecosystem-based multiple-use forest planning [ETÇAP]) comprising a traditional simulation, linear programming (LP), metaheuristics and geographic information system. The model consists of five submodels; traditional management approach to handle inventory data, an empirical growth and yield model, a simulation to conceptualize management actions, a LP technique to optimize resource allocation and a simulated annealing approach to directly create a spatially feasible harvest schedule. The ETÇAP model has been implemented in a comparative two case study areas; Denizli–Honaz and Akseki–Ibrad?. Both simulation and optimization models outperformed to the traditional management plan. The periodical change of growing stock, allowable cuts, carbon sequestration and water production are used as performance indicators. The results showed that more amount of wood could be harvested over time compared to traditional level of harvesting. It could be concluded that various management strategies allowed managers to stimulate more decision options for better outputs through intertemporal trade-offs of management interventions as the model provided tools to quantify forest dynamics over time and space. Challenges exist to establish the functional relationships between forest structure and values for better quantification and integration into the management plans. 相似文献
4.
Slađana Č. Alagić Snežana B. Tošić Mile D. Dimitrijević Jelena V. Petrović Dragana V. Medić 《Communications in Soil Science and Plant Analysis》2016,47(17):2034-2045
Inductively coupled plasma optical emission spectroscopy, in combination with calculation of various biological factors, was used in this study not only for a simple illustration of the present status of some essential and non-essential metals such as copper (Cu), zinc (Zn), nickel (Ni), lead (Pb), arsenic (As), and cadmium (Cd) in the grapevine cultivar Rkatsiteli and wild blackberry from East Serbia but also for the estimation of plant bioaccumulation potentials. Great majority of detected metal concentrations were in normal ranges except in few cases: Zn concentrations were at the level of deficiency in almost all plant parts, and some Cu and As concentrations were at the levels that could be considered phytotoxic. Biological accumulation factors provided very informative data on metal accumulation and translocation in both plants and pointed to low accumulation rates of metals except in the case of Cu, Zn, and As in some wild blackberry tissues. 相似文献
5.
Journal of Plant Diseases and Protection - Prior to the first occurrence of chestnut blight in 1976, leaf spot caused by Cylindrosporium castaneae was one of the most important diseases of European... 相似文献
6.
Kladar Nebojša Anačkov Goran Srđenović Branislava Gavarić Neda Hitl Maja Salaj Nebojša Jeremić Katarina Babović Siniša Božin Biljana 《Plant foods for human nutrition (Dordrecht, Netherlands)》2020,75(3):390-395
Plant Foods for Human Nutrition - St. John’s wort has been used for centuries in traditional medicine of many cultures, and nowadays it is well-known as a clinically important antidepressant... 相似文献
7.
The riverscape perspective recognizes the heterogeneous habitat types within the stream corridor as a single, integrated ecological
unit operating across spatial scales. Although there is ample evidence that the riverscape notion is appropriate in understanding
the physical phenomena of stream corridors, significantly less attention has focused on its ecological ramifications. To this
end, we surveyed riverscape habitat variables and bird community characteristics in the Champlain Valley of Vermont, USA.
From the data collected, we used information theoretic methodology (AICc) to model relationships between bird community attributes and key habitat variables across the riverscape. Our models with
the greatest support suggest that riverine bird communities respond to a suite of characteristics; representing a variety
of riverscape habitats at the in-stream, floodplain, and riparian levels. Channel slope, drainage area, percent conifers,
and in-stream habitat condition were among the most influential variables. We found that piscivores are potentially important
indicators of riverscape condition, responding to a host of variables across the riverscape. Our results endorse a holistic
approach to assessing and managing the mosaic of patches in the riverscape and suggest that a riverscape approach has significant
conservation potential. 相似文献
8.
Pakeza Drkenda Osman Musić Slađana Marić Darko Jevremović Sanja Radičević Metka Hudina Sabina Hodžić Achim Kunz Michael M. Blanke 《Erwerbs-Obstbau》2018,60(4):295-304
The objective of the joint project between the two universities of Bonn and Sarajevo was to study the effects of climate change associated with warmer winter and spring temperatures on fruit tree phenology. Changes in flowering date of apple and cherry were correlated with local weather data obtained concomitantly on-site at four locations in the Balkan countries Slovenia, Serbia, B & H and at Bonn, Germany.Phenological data of flower opening (F1; BBCH 61) of apple cv. ‘Golden Delicious’ originated from 55 years at Cacak (44?°N, Serbia) and at Klein-Altendorf, University of Bonn (50?°N), cv. ‘Bobovec’ from the University of Ljubljana (46?°N, Slovenia) and cherry cv. ‘Burlat’ (35 years at Klein-Altendorf, 50?°N) and 20–30 years at Tuzla (44?°N, B & H) and Mostar (43?°N, Bosnia & Herzegovina; B & H).The annual precipitation showed a negligible change in the last 55 years of ±5% in the Balkan countries (e.?g. Cacak, 699?mm), but only ±1.8% at Klein-Altendorf (605?mm) with a slight shift to more winter rainfall.Regression analysis showed an increase in mean temperature of 1.7?°C (annual) and 1.45?°C for the vegetation period at Klein-Altendorf (last 55 years), Germany. In the evaluated Balkan stations, the greatest increase in annual air temperature between two climate phases (until 1987 versus from 1988 until now) was at Ljubljana (1.4?°C) and Cacak (1.2?°C) in contrast to the least increase (0.3?°C) at Tuzla (annual average 10?°C) and an intermediate value (0.9?°C) in the warmer Mostar (annual average 14.5?°C).This recent temperature increase advanced flower opening by 10–14 days for apple such as cv. ‘Golden Delicious’ at Cacak and 7–10 days (last 55 years) at Bonn and 4–5 days (last 35 years) for the early cherry cv. ‘Burlat’ at Klein-Altendorf/Bonn; at Mostar and Tuzla, the effect of climate change was greater with the early cherry cv. ‘Burlat’ (26 days) compared with the difference of the late cherry cultivar (16 days). Before recent climate change (1973–1987), cherry flower was advanced by 10 days in the warmer med climate at Mostar but delayed by 16 days in the cooler Tuzla. The results, i.?e. the flower advancement in the Continental climate but flower delay in the med climate, are discussed with respect to the risk of late frost and countermeasures to combat climate change effects. 相似文献
9.
Emily Fobert Grzegorz Zięba Lorenzo Vilizzi Michael J. Godard Michael G. Fox Saulius Stakėnas Gordon H. Copp 《Ecology of Freshwater Fish》2013,22(1):106-116
Predictions of future climate change include shifts in patterns of precipitation, evapotranspiration and water run‐off, resulting in increased periods of drought as well as variability and intensity of rainfall events. In the United Kingdom, the non‐native North American sunfish, pumpkinseed Lepomis gibbosus (L.), is expected to benefit from these changes. We examine how hydrological variability induced by predicted changes in climate will affect the dispersal and spread of pumpkinseed in England by: (i) determining the relationship between discharge regime and pumpkinseed propagule pressure; (ii) examining a newly‐established pumpkinseed population following a flood event in 2007; and (iii) comparing the growth and life‐history traits of this new population with fish collected from the source population to demonstrate how the pumpkinseed's life‐history plasticity contributes to its success as a coloniser. Using Bayesian modelling, we determined that the number of pumpkinseed escapees is likely to increase with increasing discharge. The newly‐established pumpkinseed population showed fast juvenile growth, early age at maturity and small size at maturity. These traits differed significantly from the source population, specifically total length (TL) means at ages 1 and 2 were significantly greater in the new population, whereas TL at age 4 was significantly greater in the source population, and a significantly higher proportion of mature females were found at smaller size classes in the newly established pumpkinseed population. This study demonstrates the potential link between hydrological variability (current and future) and the dispersal of non‐native pumpkinseed, leading to the establishment of new populations. 相似文献
10.
This study focuses on the problem of irregular diameter structure in a silver fir–beech selection (plenter) forest with a “surplus” of large diameter trees and a lack of natural regeneration and small diameter trees. We sampled 274 plots (900 m2 each) in the Belevine research site (266.24 ha) in the mountain region Gorski Kotar (Croatia), where diameter (dbh) distribution, diameter increment, and natural regeneration were analyzed in detail. A low density of natural regeneration, weak annual recruitment of small (10 cm dbh) diameter trees (only five trees per hectare), delayed diameter growth of trees, and a low annual rate of trees reaching the next dbh class were attributed to the current irregular dbh structure. The stand development prediction for the next 50 years is based on a simulation model, which considers the current diameter structure, increment, recruitment, and future cutting regime. Intensive cutting in the first of five 10-year cutting cycles (intensity higher of 25%) is needed to initiate natural regeneration and to accelerate growth of young silver fir trees. In the next 50 years, the irregular diameter structure will be gradually improved. 相似文献