This study was carried out in ?scehisar district of Afyonkarahisar on ‘0900-Ziraat’ sweet cherry cultivar for two successive years in 2011 and 2012. Ten different applications consisting of 80?g FeSO4.7H2O tree?1, 20?g FeEDDHA tree?1, 420?mL TK?-Hümas tree?1, 80?g FeSO4.7H2O + 420?mL TK?-Hümas tree?1, 200?g powder sulphur (S) tree?1, 80?g FeSO4.7H2O + 200?g powder S tree?1, 25?g ZnSO4.7H2O tree?1, 25?g ZnSO4.7H2O + 420?mL TK?-Hümas tree?1 and 25?g ZnSO4.7H2O + 200?g powder S tree?1 were subjected for determination of their effect on vegetative growth of sweet cherry. In this study, shoot diameter, shoot length, leaf total chlorophyll content, leaf area and leaf iron (Fe) and zinc (Zn) contents were obtained. Shoot length, shoot diameter and leaf area showed general increases in 80?g FeSO4.7H2O + 200?g powder S tree?1 and 25?g ZnSO4.7H2O + 200?g powder S tree?1 treatments.The results clearly indicated that he treatments had different effects on the shoot length and shoot diameter although there was a differences between the experimental years. Particularly, significantly positive effects of the treatments on leaf total chlorophyll was apparent for the second year’s observations. In addition, Fe and Zn concentrations in leaf were markedly increased in response to the treatments. 相似文献
Herbicide treatments in viticulture can generate highly contrasting mosaics of vegetated and bare vineyards, of which vegetated fields often provide better conditions for biodiversity. In southern Switzerland, where herbicides are applied at large scales, vegetated vineyards are limited in extent and isolated from one another, potentially limiting the distribution and dispersal ability of organisms.
Objectives
We tested the separate and interactive effects of habitat amount and fragmentation on invertebrate abundance using a multi-scale framework, along with additional environmental factors. We identified which variables at which scales were most important in predicting patterns of invertebrate abundance.
Methods
We used a factorial design to sample across a gradient of habitat amount (area of vegetated vineyards, measured as percentage of landscape PLAND) and fragmentation (number of vegetated patches, measured as patch density PD). Using 10 different spatial scales, we identified the factors and scales that most strongly predicted invertebrate abundance and tested potential interactions between habitat amount and fragmentation.
Results
Habitat amount (PLAND index) was most important in predicting invertebrate numbers at a field scale (50 m radius). In contrast, we found a negative effect of fragmentation (PD) at a broad scale of 450 m radius, but no interactive effect between the two.
Conclusions
The spatial scales at which habitat amount and fragmentation affect invertebrates differ, underpinning the importance of spatially explicit study designs in disentangling the effects between habitat amount and configuration. We showed that the amount of vegetated vineyards has more influence on invertebrate abundance, but that fragmentation also contributed substantially. This suggests that efforts for augmenting the area of vegetated vineyards is more beneficial for invertebrate numbers than attempts to connect them.
Knowledge of the effects of farmer practices on population genetic parameters of peach palm (Bactris gasipaes Kunth) is relevant to the improvement and conservation of the palm’s genetic resources. Microsatellite markers were used
to assess genetic diversity and population structure of peach palm in swidden-fallow agroforestry systems in northeastern
Peru. The study covered eight communities, comprising two study areas 160 km apart – one occupied by indigenous Amerindians
and the other by mixed race campesinos. Simultaneous analysis of an ex situ peach palm germplasm collection provided a means to compare population genetic parameters. Farmers who were surveyed on seed
selection practices for peach palm reported that an average of only four palms (4.3 for campesino and 1.5 for indigenous populations)
were used to provide seed for the establishment of the forest gardens sampled. As expected, inbreeding coefficients observed
within communities were relatively high (f = 0.105 − 0.210), however, observed heterozygosities within communities were also high (0.625–0.741). A metapopulation approach
was used to describe migration within and among regions, implying a hierarchical structure of gene flow which maintains relatively
high levels of genetic diversity. Seed migration was found to occur over longer distances (≤600 km) and at a higher frequency
(46% of palms sampled) in the indigenous study area, and a proportionally greater number of alleles was found (49 vs. 43 over
three loci) with twice as many private alleles occurring only in the indigenous populations. The farmers’ practice of preserving
remnant palms through successive swidden generations may have contributed to the maintenance of alleles by reducing the severity
of founder effects. Although the campesino study area exhibited a significant (20% of the variation; p < 0.01) isolation-by-distance relationship across 35 km distance, in general, both study populations had relatively limited
genetic structure (θ = 0.012–0.03), which is believed to have resulted from the exchange of seeds over long distances and
periods of time. 相似文献
Background, Aim and Scope The distribution of sediments in estuarine beaches is controlled by the interactions between sediment supply, hydrodynamic
processes and human intervention. The main purpose of this study is to characterize the sediments of Tagus estuarine beaches
in order to understand their origin and to contribute to a better knowledge of the Tagus estuary sediment budget.
Methods Surface sediment samples were collected across beach profiles and sand grain size analysis was performed by dry sieving. Grain
size statistics for the median (d50) and standard deviation (SDM) were obtained using the Moment method. This study was complemented by a qualitative evaluation
of the sediment composition. Cross-shore topographic surveys were conducted for selected sampling sites.
Results Tagus estuarine beach sediments are mainly composed of quartz sand particles which are fine-grained and well sorted near the
mouth of the estuary and medium to coarse-grained and moderately sorted in the inner domain. Compositional results show evidence
of active anthropogenic sediment sources, especially in the coarser fractions.
Discussion The analysis of the textural and compositional characteristics of beach sediments in the inner estuarine domain is compatible
with local sedimentary sources, while a marine signature is present at the mouth and inlet channel sediments. In the inner
domain, differences in the sedimentary processes are represented by the textural characteristics of the sediments, such as
the sorting degree and the gravel content. Sediment characteristics also reflect human intervention in the system, with the
introduction of anthropogenic and allochthonous particles and the mixture of sediments from different sources.
Conclusions The sediments of the inner Tagus estuarine beaches are derived from local Plio-Pleistocene outcrops while inlet and outer
estuary beaches reveal a dominant marine source. Beach textural variability observed in the inner domain is not related to
wave forcing gradients, but mainly to variations in the sedimentary processes along the estuarine margins and to human intervention.
Results show that the Tagus estuarine beaches depended, almost exclusively, on sediment input from local sources until the
last century. With increasing human occupation, sediment transfers became dominated by anthropogenically related activities
mainly connected with the occupation of estuarine margins and dredging.
Recommendations and Perspectives Further studies should extend the present level of knowledge in what concerns sand transport patterns through additional compositional
and geochemical analysis, and the development of new techniques in order to allow the quantitative evaluation of the impact
of human activities on the sediment budget. 相似文献
Soil enzymes are linked to microbial functions and nutrient cycling in forest ecosystems and are considered sensitive to soil
disturbances. We investigated the effects of severe soil compaction and whole-tree harvesting plus forest floor removal (referred
to as FFR below, compared with stem-only harvesting) on available N, microbial biomass C (MBC), microbial biomass N (MBN),
and microbial biomass P (MBP), and dehydrogenase, protease, and phosphatase activities in the forest floor and 0–10 cm mineral
soil in a boreal aspen (Populus tremuloides Michx.) forest soil near Dawson Creek, British Columbia, Canada. In the forest floor, no soil compaction effects were observed
for any of the soil microbial or enzyme activity parameters measured. In the mineral soil, compaction reduced available N,
MBP, and acid phosphatase by 53, 47, and 48%, respectively, when forest floor was intact, and protease and alkaline phosphatase
activities by 28 and 27%, respectively, regardless of FFR. Forest floor removal reduced available P, MBC, MBN, and protease
and alkaline phosphatase activities by 38, 46, 49, 25, and 45%, respectively, regardless of soil compaction, and available
N, MBP, and acid phosphatase activity by 52, 50, and 39%, respectively, in the noncompacted soil. Neither soil compaction
nor FFR affected dehydrogenase activities. Reductions in microbial biomass and protease and phosphatase activities after compaction
and FFR likely led to the reduced N and P availabilities in the soil. Our results indicate that microbial biomass and enzyme
activities were sensitive to soil compaction and FFR and that such disturbances had negative consequences for forest soil
N and P cycling and fertility. 相似文献
The C mineralisation pattern during the early stage of decomposition of plant materials is largely determined by their content
of different carbohydrates. This study investigated whether detailed plant analysis could provide a better prediction of C
mineralisation during decomposition than proximate analysis [neutral detergent solution (NDF)/acid detergent solution (ADF)].
The detailed analysis included sugars, fructans, starch, pectin, cellulose, lignin and organic N. To determine whether differences
in decomposition rate were related to differences in hemicellulose composition, the analysis particularly emphasised the concentrations
of arabinose and xylose in hemicelluloses. Carbon dioxide evolution was monitored hourly in soil amended with ten different
plant materials. Principal component and regression analysis showed that C mineralisation during day 1 was closely related
to free sugars, fructans and soluble organic N components (R2 = 0.83). The sum of non-cellulose structural carbohydrates (intermediate NDF/ADF fraction) was not related to C mineralisation
between days 1 and 9. In contrast, a model including starch and protein in addition to the non-cellulose structural carbohydrates,
with the hemicelluloses replaced by arabinose and xylose, showed a strong relationship with evolved CO2 (R2 = 0.87). Carbon mineralisation between days 9 and 34 was better explained by xylan, cellulose and lignin (R2 = 0.72) than by lignocellulose in the ADF fraction. Our results indicated that proximate analyses were not sufficient to
explain differences in decomposition. To predict C mineralisation from the range of plant materials studied, we propose a
minimum set of analyses comprising total N, free sugars, starch, arabinose, xylan, cellulose and lignin. 相似文献
Faidherbia albida is an ideal agroforestry tree commonly intercropped with annual crops like millet and groundnuts in the dry and densely populated areas of Africa. With its peculiar reverse phenology, it makes growth demands at a different time from that of crops. In addition, it deposits great amount of organic fertilizer on food crops. Leaves entering soils are comparable to fertilization of almost 50 t·ha 1 ·year 1 of manure in dense stands of 50 large trees per ha. These nutrients help maximize agricultural production and reduce the need for a fallow period on poorer soils. Research has shown that millet grown under F. albida yielded 2.5 and 3.4 fold increases in grain and protein, respectively. Animals eat pods which contain mean amounts of crude protein of 20.63% and carbohydrate of 40.1% in seeds. Moreover, the continued existence of F. albida in agroforestry parklands as in Ethiopia and Mali signifies the success of traditional conservation measures. Modern scientists have also developed much interest in the role of agroforestry in maintaining long-term biological balance between agriculture and livestock production systems. To ensure food security, which still remains a major challenge in sub-Saharan Africa, and concurrently minimize environmental degradation, promotion of agroforestry that specifically involves indigenous trees is crucial. We discuss the prospective role of F. albida in alleviating poverty while simultaneously protecting the environment from factors associated with, for example, deforestation and loss of biodiversity. The overall aim is to promote wide-scale adoption of F. albida as a valuable tree crop in farming systems, particularly in those areas where it remains unexploited. 相似文献
The morphological, physical, and mechanical properties of the nonwood plant fiber bundles of ramie, pineapple, sansevieria,
kenaf, abaca, sisal, and coconut fiber bundles were investigated. All fibers except those of coconut fiber had noncircular
cross-sectional shapes. The crosssectional area of the fiber bundles was evaluated by an improved method using scanning electron
microscope images. The coefficient factor defined as the ratio of the cross-sectional area determined by diameter measurement,
to the cross-sectional area determined by image analysis was between 0.92 and 0.96 for all fibers. This indicated that the
area determined by diameter measurement was available. The densities of the fiber bundles decreased with increasing diameters.
The diameters of each fiber species had small variation of around 3.4%-9.8% within a specimen. The tensile strength and Young’s
modulus of ramie, pineapple, and sansevieria fiber bundles showed excellent values in comparison with the other fibers. The
tensile strength and Young’s modulus showed a decreasing trend with increasing diameter of fiber bundles. 相似文献
Biomass and net primary productivity (NPP) are two important parameters in determining ecosystem carbon pool and carbon sequestration. The biomass storage and NPP in desert shrubland of Artemisia ordosica on Ordos Plateau were investigated with method of harvesting standard size shrub in the growing season (June-October) of 2006. Results indicated that above- and belowground biomass of the same size shrubs showed no significant variation in the growing season (p〉0.1), but annual biomass varied significantly (p〈 0.01). In the A. ordosica community, shrub biomass storage was 699.76-1246.40 g.m^-2 and annual aboveground NPP was 224.09 g-m^-2·a^-1. Moreover, shrub biomass and NPP were closely related with shrub dimensions (cover and height) and could be well predicted by shrub volume using power regression. 相似文献