共查询到20条相似文献,搜索用时 46 毫秒
2.
3.
4.
5.
6.
7.
8.
J. Alberto Gallardo-Cruz Eduardo A. Pérez-García Jorge A. Meave 《Landscape Ecology》2009,24(4):473-482
Topography strongly affects the distribution of insolation in the terrain. Patterns of incoming solar radiation affect energy
and water balances within a landscape, resulting in changes in vegetation attributes. Unlike other regions, in seasonally
dry tropical forest areas the potential contribution of topography-related environmental heterogeneity to β-diversity is unclear. In Mt. Cerro Verde (Oaxaca), S. Mexico, we: (1) modelled potential energy income for N- and S-facing
slopes based on a digital elevation model, (2) examined the response of vegetation structure to slope aspect and altitude
and (3) related variations in plant diversity to topography-related heterogeneity. Vegetation survey and modelling of potential
energy income (SOLEI-32 model) were based on 30 plots equally distributed among three altitudinal belts defined for each slope
of the mountain; combining the three altitudinal belts and the two slopes produced six environmental groups, represented by
five vegetation plots each. Potential energy income was about 20% larger on the S than on the N slope (9,735 versus 8,138 MJ/m2), but it did not vary with altitude. In addition, the temporal behaviour of potential energy income throughout the year differed
greatly between slopes. Vegetation structure did not show significant changes linked to the environmental gradients analysed,
but altitude and aspect did affect β-diversity. We argue that the classic model of slope aspect effect on vegetation needs reconsideration for tropical landscapes.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorised users. 相似文献
9.
Anna-Maria Rautio Torbjörn Josefsson Anna-Lena Axelsson Lars Östlund 《Landscape Ecology》2016,31(2):337-349
Context
Past human land use has received increasing attention as an important driver of ecosystem change also in seemingly natural landscapes. Quantification of historical land use is therefore critical for assessing the degree of human impact and requires integration of ecology, history and archaeology.Objective
This study aims to assess and compare levels of resource use by different actors during 355 years across a large landscape of northern Sweden.Method
Data on resource use derived from case studies were extrapolated using demographic data to estimate harvested resources at the landscape scale. Here, we examined the use of the key-specie Scots pine by native Sami peoples and farmers and through commercial logging, and reconstructed historical forest conditions in order to interpret harvest levels and sustainability.Results
We show that (1) the pre-industrial use of Scots pine resources in Pite Lappmark was sustainable from a landscape perspective, and (2) that the early commercial logging, in contrast, was not sustainable. Large and old Scots pine trees were logged at a very high rate, reaching up to 300 % of the annual ingrowth.Conclusion
We suggest that historical landscape studies should incorporate analysis at different spatial scales, as such an approach can mirror the overall use of resources. Only then can land use data be applied across larger spatial scales, function as reference values and be compared to those of other regions, time-periods and types of human impact.10.
The mango (Mangifera indica L.) is native to South and Southeast Asia, from where it has been distributed worldwide to become one of the most cultivated fruits in the tropics. It is the national fruit of India. In India, harvest and sale of mangoes take place during March-May and the fruits have high economic value in India. Studies were first time conducted on mango fruits to observe the severity of fruit cracking incidence. The stone was exposed in case of longitudinal type cracking and never exposed in star type cracking. The longitudinal cracking was 3.8, 3.4 and 1.7 % and star type cracking was 0.3, 1.8 and 0.02 % during 2009, 2010 and 2011, respectively. The lesser pulp thickness and higher stone weight in fruit cracked samples may have responsible for fruit cracking. There was a close relationship between fruit cracking and 3 months average weather conditions. The maximum temperature had positive relation with total fruit cracking. 相似文献
11.
The aim of this research is to compose the energy input-output analysis of plum in Nevsehir province in Turkey. This research was conducted at the plum cultivating facilities during the 2015–2016 production seasons in Nevsehir province of Central Anatolian Region in Turkey. The agricultural input energies and output energies used in plum cultivation were calculated to determine the energy input-output analysis. According to the research findings, the energy inputs in plum cultivation were calculated respectively 3920?MJ ha?1 (44.99%) chemical fertilizers energy, 1618.91?MJ ha?1 (18.58%) diesel fuel energy, 1125.85?MJ ha?1 (12.92%) chemicals energy, 1069.20?MJ ha?1 (12.27%) machinery energy, 723.24?MJ ha?1 (8.30%) human labour energy and 255?MJ ha?1 (2.93%) irrigation water energy. Production output plum yield were calculated as 12,112.50?MJ ha?1. The energy output/input ratio, specific energy, energy usage efficiency and net energy calculations were calculated respectively as 1.39, 1.37?MJ kg?1, 0.73?kg MJ?1 and 3400.30?MJ ha?1. 相似文献
12.
Yield management is important subject in modern grape growing and winter pruning and cluster thinning treatments were used for yield control. Standard cluster thinning is generally labor intensive and expensive method and grape growers try to new methods, which are alternative to cluster thinning for reducing berry set. The goal of the present research was to investigate the effects of chemical thinning treatments such as ethephon (ETH), gibberellic acid (GA3), naphthalene acetic acid (NAA) and non-chemical thinning treatments such as early leaf removal (ELR) and standard cluster thinning (SCT) on decreasing grape yield and enhancing berry composition of cv. Shiraz. In this study, percentages of berry set of cv. Shiraz were decreased by both chemical and non-chemical thinning treatments compared to Control. The results from these two different thinning methods shown certainly significant differences in berry composition of cv. Shiraz. Eventually, the best results in improved quality characteristics of cv. Shiraz were obtained from ELR treatment and treatments of ELR, ETH, GA3, NAA and SCT successively resulted in considerable enhancements in quality attributes of cv. Shiraz. 相似文献
13.
The aim of this study is to reveal the energy balance of walnut in Central Anatolian Region in Turkey. This study has been conducted at the walnut cultivating facilities during the 2014–2015 production season in K?r?ehir, Konya, Nev?ehir and Ni?de provinces of Central Anatolian Region in Turkey, where walnut cultivation is intense. In the study, a total of 28 walnut cultivation facilities, yielding walnut, have been selected through Neyman method and surveys and observations have been performed in these facilities. The agricultural input energies and output energies used in walnut cultivation have been calculated to define the energy use efficiency. According to the study findings, the energy inputs in walnut cultivation are calculated respectively 17,851.33?MJ ha?1 (74.40%) chemical fertilizer energy, 2229.87?MJ ha?1 (9.29%) fuel energy, 1640.64?MJ ha?1 (6.83%) irrigation water energy, 1539?MJ ha?1 (6.41%) machine energy, 508.02?MJ ha?1 (%2.11) chemical energy, 180.35?MJ ha?1 (0.75%) human labour energy and 43.33?MJ ha?1 (0.18%) farm manure energy. Production outputs have been calculated as 14,679.52?MJ ha?1. Following the energy calculations, the output/input ratio, specific energy, energy efficiency and net energy calculations have been calculated respectively as 0.61, 30.20?MJ kg?1, 0.03?kg MJ?1 and ?9313.02?MJ ha?1. Benefit-cost ratio was calculated as 1.88, by dividing the gross value of production by the total cost of production per hectare in walnut production. 相似文献
14.
Background
Noise (errors) in scientific data is endemic and may have a detrimental effect on statistical analyses and experimental results. The effects of noisy data have been assessed in genome-wide association studies for case-control experiments in human medicine. Little is known, however, on the impact of noisy data on genomic predictions, a widely used statistical application in plant and animal breeding.Results
In this study, the sensitivity to noise in the data of five classification methods (K-nearest neighbours—KNN, random forest—RF, ridge logistic regression—LR, and support vector machines with linear or radial basis function kernels) was investigated. A sugar beet population of 123 plants phenotyped for a binary trait and genotyped for 192 SNP (single nucleotide polymorphism) markers was used. Labels (0/1 phenotype) were randomly sampled to generate noise. From the base scenario without errors in the labels, increasing proportions of noisy labels—up to 50 %—were generated and introduced in the data.Conclusions
Local classification methods—KNN and RF—showed higher tolerance to noisy labels compared to methods that leverage global data properties—LR and the two SVM models. In particular, KNN outperformed all other classifiers with AUC (area under the ROC curve) higher than 0.95 up to 20 % noisy labels. The runner-up method, RF, had an AUC of 0.941 with 20 % noise.15.
Ali Khadivi 《Erwerbs-Obstbau》2018,60(4):289-294
Pistachio (Pistacia vera L.) is considered to be the most widely cultivated species in the genus Pistacia and regarded as the most probable ancestral species within the genus. As one of the oldest nut crops in human history, pistachio nuts have a high nutritional value and are commercially important. In the present study, the genetic variation of pistachio genotypes was investigated by nuclear SSR markers. The transferability of the SSR markers was high across genotypes, thus, flanking regions of the SSRs are conserved in the studied genotypes. High level of polymorphism was detected among the studied genotypes. The seven SSR primer pairs generated a total of 18 alleles that 13 of them were polymorphic among the genotypes. The range of the polymorphic alleles was 1 (for Ptms9, Ptms40, Ptms41, and Ptms42) to 5 (for Ptms7 locus) with an average of 2.57. The amplified allele sizes ranged from 120 to 250?bp. Pair-wise genetic similarity coefficients varied from 0.20 to 0.75. The UPGMA dendrogram differentiated the genotypes into two major clusters. The present results may be used for the conservation, core collection and future breeding of the pistachio. 相似文献
16.
In this study, average weight, colour, soluble solids content and titratable acidity were determined as quality parameters of strawberry fruits while ascorbic acid, total anthocyanins, total phenolics, total flavonoids, minerals and trace elements content as nutritional parameters. All these attributes along with the DPPH radical scavenging activity were screened in two strawberry genotypes grown on the same site at the ripe stage. Also, the phenolic profiles of the strawberry fruits were obtained by HPLC. Except colour, results showed no significant differences between cultivars in quality parameters. Ascorbic acid found for ‘Premial’ cv. (81.62?mg/100?g) was twice the amount found in ‘Magic’ cv. (42.15?mg/100?g), total phenolics varied from 207.95 (cv. ‘Premial’) to 249.98 (cv. ‘Magic’) mg GAE/100?g while total flavonoid content in fruits of ‘Magic’ cultivar (79.56?mg/100?g) was 2?fold higher than the one of the ‘Premial’ cv. The quercetin content ranged from 2.72 to 4.66?mg/100?g, whereas free ellagic acid ranged from 6.79 to 9.03?mg/100?g. The pale shiny fruits of ‘Premial’ cv. (higher L*, ho and chroma index) had a lower total anthocyanin content (19.07?mg CG/100?g) than the bluish fruits of the ‘Magic’ cv. (23.96?mg CG/100?g). An inverse relationship between the levels of ascorbic acid and anthocyanin contents was also noticed in strawberry samples. Significant differences were found also in minerals and trace elements content of the two strawberry cultivars. The results revealed the importance of genetic background for the content of antioxidant compounds in strawberry fruits. 相似文献
17.
Utilization from bio fertilization is well known a considerable tool to improve the yield and fruit quality of various crop fruits through the increasing emphasis on maintain of soil health, minimize environmental pollution and decrease the use of chemical fertilization. In this study, in order to improve wine grape quality features of cv. Shiraz, four different doses of foliar microbial fertilizer, including 0, 1000, 2000 and 3000?ppm were applied at two different terms as Term I (mostly; pre-bloom applications) and Term II (mostly; post-bloom applications). However, there were no influences of application terms of foliar microbial fertilizer treatments; treatment doses had considerable effects on yield and quality parameters. The lowest p-values, meaning the highest berry quality, from doses of foliar microbial fertilizer were obtained from 2000?ppm (105.08?μW), 1000?ppm (110.40?μW), 3000?ppm (112.97?μW) and 0?ppm (119.58?μW). Comparing the applications of foliar microbial fertilizer, it was observed that doses of 2000?ppm (3155.56?mg/kg), 1000?ppm (3000.92?mg/kg) and 3000?ppm (2530.19?mg/kg) exhibited higher total phenolic compounds content when compared with 0?ppm treatment (2206.97?mg/kg). Berries from grapevines applied with the doses of 2000, 1000 and 3000?ppm foliar microbial fertilizer respectively shown higher total anthocyanin content such as 1230.19, 1160.85 and 865.86?mg/kg compared to 0?ppm (637.37?mg/kg). As a result, research the findings indicated that 2000 and 1000?ppm doses of foliar microbial fertilizer were obviously effective on wine grape quality features of cv. Shiraz in terms of electrochemical property, total phenolic compounds content and total anthocyanin content. 相似文献
18.
Amy B. Mui Brennan Caverhill Bob Johnson Marie-Josée Fortin Yuhong He 《Landscape Ecology》2017,32(3):531-546
Context
Landscapes and animal behavior can exhibit temporal variability and connectivity estimates should consider this phenomenon. In many species, timing of activities such as nesting, mate searching, and hibernation occurs during distinct periods in which movement events may differ, along with physical characteristics of the surrounding landscape.Objectives
We estimate movement, landscape conductance, and patch importance for a turtle species across two seasonal activity periods (spring, late summer) in a fragmented agricultural region. Three connectivity approaches are compared to identify their advantages and disadvantages.Methods
A least-cost distance model, circuit-based approach, and patch-based index were used to collectively describe the potential functional connectivity of Blanding’s turtle (Emydoidea blandingii) across a multi-temporal scale in an agricultural region of south western Ontario.Results
Connectivity decreased further into the active season exhibited through lower conductance of the landscape and fewer pathways, while the importance of habitat nodes shifted due to temporal variability in the number and distribution of nodes. Models provided different yet complimentary information, with least-cost models overestimating discrete pathways yet providing a secondary measure of landscape barriers. The circuit-based model estimated corridors of least resistance providing an overall characterization of the landscape, while patch-based indices provided key information on the importance of individual habitat patches.Conclusion
Findings highlight the importance of including a temporal aspect in connectivity modelling as results demonstrate a change in functional connectivity over time. We also recommend employing multiple connectivity metrics to capture variation in movement behavior.19.
Grape growers may occasionally face difficulties in grape skin coloration and low total soluble solids content in growing of early ripening table grape cultivars. In order to overcome these difficulties, it can be utilized from foliar biostimulants treatments. The purpose of this study, carried out 2015 growing season in Tekirda?, Turkey, was to compare the effects of doses of two different biostimulants, enhancing table grape quality characteristics of cv. Tarsus Beyaz?, cv. Trakya Ilkeren and cv. Yalova Incisi. For this aim, it was focused on three different doses for both biostimulants, including 0, 1750 and 3500?ppm (respectively, Control, BSt A-1 and BSt A-2) for first biostimulant and 0, 3500 and 4500?ppm (respectively, Control, BSt B-1 and BSt B-2) for second biostimulant. As a result, present research demonstrated that BSt B-2 and BSt A-2 treatments especially enhanced most of table grape quality characteristics in cv. Tarsus Beyaz?, cv. Trakya Ilkeren and cv. Yalova Incisi. 相似文献
20.
‘Violet Peafowl’、‘Starry Diamond’、‘Rainbow in May’和‘Bright Vitas’是从粗根鸢尾(Iris tigridia)的实生后代中选育出的新品种,株高12 ~ 14 cm,花色分别为紫、蓝紫、粉紫、蓝,花朵于7:30—14:00开放,花期4—5月,果期6—8月,具有耐寒、耐旱、耐盐碱等特性,可以在北方露地越冬。 相似文献