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This study investigated the effect of high temperature and drought (during grain-filling) on the quality and components yield of five winter wheat varieties. Drought and drought + heat were found to have a much greater influence on the yield and quality than heat stress alone. Averaged over the varieties, the yield losses were 57% after drought, 76% after drought + heat, and only 31% after heat stresses. The reductions in the unextractable polymeric protein fraction and glutenin-to-gliadin ratio indicated a poorer grain yield quality, despite the higher protein content. Quality deterioration was observed after drought or drought + heat, while high temperatures alone resulted in no change or in a better ratio of protein components. A significant negative correlation was observed between starch granule size and relative protein content after drought.

We determine the total polyphenol content (TPC) and antioxidative potential (AOP) in external and internal leaves of different cultivars of chicory, both before and after storage. We analysed the red cultivars Leonardo, Trevisio, Mesola, Verona, and Chioggia, the red-spotted cultivar Castelfranco, and the sweet cultivars Jupiter, Uranus, and Mercurius. The chicories were stored at temperatures from 0.1 deg C to 0.8 deg C and relative humidity from 90% to 95%. Cultivar and leaves significantly influenced TPC and AOP, while storage influenced AOP only. The outer leaves showed significantly higher TPC and AOP. The TPC in chicory ranged from 20 mg/100 g to 400 mg/100 g fresh weight and the AOP ranged from 0.20 micromol/g to 0.85 micromol/g fresh weight.

Crop loss to wildlife impedes local support for conservation efforts at Kibale National Park, Uganda. Systematic monitoring of crop loss to wildlife (mammals larger than 3 kg) and livestock was conducted in six villages around Kibale over a 2-year period. Five wildlife species accounted for 85% of crop damage events: baboons, bushpigs, redtail monkeys, chimpanzees, and elephants. Marked variation in frequency and extent of damage is reported within villages, between villages, and between wildlife species. Fields lying within 500 m of the forest boundary lost 4-7% of crops per season on average, but the distribution of damage was highly skewed such that maize and cassava fields were on occasion completely destroyed. Multivariate analysis was used to test predictors of damage, including human population density, guarding, hunting, sight distance, and distance from the forest. Tests were performed at two levels of analysis, field and village. Distance from the forest edge explained the greatest amount of variation in crop damage, although hunting also influenced the extent of crop damage. Elephants inflicted catastrophic damage to farms but their forays were rare and highly localized. Livestock caused considerable damage to crops but farmers seldom complained because they had institutionalized modes of restitution. Although most of the crop damage by wildlife is restricted to a narrow band of farmers living near the forest edge, risk perception among these farmers has been amplified by legal prohibitions on killing wild animals. Elevating local tolerance for wildlife will require diverse approaches, including channeling economic benefits to Kibale's neighbors and providing compensation in limited cases.

Statistical analyses were used in order to evaluate if it is possible to reduce sample sizes when assessing sugar beet losses and root damage associated with sugar beet harvesting. As shown by our results, the number of plants may be reduced from 1,500 required by the Czech standard to 570 plants when evaluating root damage and to 1,065 plants when evaluating the quality of cutting.

It is necessary to develop a non-destructive technique for kiwifruit quality analysis because the machine injury could lower the quality of fruit and incur economic losses. Bruises are not visible externally owing to the special physical properties of kiwifruit peel. We proposed the hyperspectral imaging technique to inspect the hidden bruises on kiwifruit. The Vis/NIR (408-1,117 nm) hyperspectral image data was collected. Multiple optimal wavelength (682, 723, 744, 810, and 852 nm) images were obtained using principal component analysis on the high dimension spectral image data (wavelength range from 600 nm to 900 nm). The bruise regions were extracted from the component images of the five waveband images using RBF-SVM classification. The experimental results showed that the error of hidden bruises detection on fruits by means of hyperspectral imaging was 12.5%. It was concluded that the multiple optimal waveband images could be used to constructs a multispectral detection system for hidden bruises on kiwifruits.

Riparian zones are vital components of the landscape. Much attention has been focused on the question of how wide a buffer is needed to protect the original riparian environment. We sampled five streams 2-4 m wide and associated riparian ecosystems before and after clearcutting in western Washington. Buffers ranging from 17 to 72 m wide were left intact at all sites when harvesting. Our objectives were: (1) to characterize pre-harvest microclimatic gradients across riparian ecosystems, from the stream to the upland; (2) to identify effects of harvesting on these gradients; and (3) to describe effects of buffer width and near-stream microclimate on stream microclimate. Six weather stations measuring air temperature, soil temperature, surface air temperature, relative humidity, short-wave solar radiation, and wind speed were installed along transects running across the stream and into the upland, and two reference stations were established, one in an upland clearcut and one in an upland interior forest. Pairwise comparison tests were used to evaluate statistical differences between stations along transects for determination of gradient extent. Pre-harvest riparian gradients existed for all variables except solar radiation and wind speed, and values generally approached forest interior values within 31-62 m from the stream. After harvesting, microclimate values at the buffer edge and each subsequent location toward the upland began to approximate clearcut values instead of forest interior values, indicating an interruption or elimination of the stream-upland gradient. In addition, regression analyses showed that stream microclimate was affected to some degree by buffer width and microclimate in the surrounding area. We conclude that a buffer at least 45 m on each side of the stream is necessary to maintain a natural riparian microclimatic environment along the streams in our study, which were characterized by moderate to steep slopes, 70-80% overstory coverage (predominantly Douglas-fir and western hemlock), and a regional climate typified by hot, dry summers and mild, wet winters. This buffer width estimate is probably low, however, since it assumes that gradients stabilize within 30 m from the stream and that upslope edge effects extend no more than 15 m into the buffer (a low estimate based on other studies). Depending on the variable, required widths may extend up to 300 m, which is significantly greater than standard widths currently in use in the region (i.e., ∼10-90 m). Our results indicate that even some of the more conservative standard buffer widths may not be adequate for preserving an unaltered microclimate near some streams. Additional site-specific data are needed for different site conditions in order to determine whether generalizations can be made regarding near-stream microclimate.

The effects of commercial logging on tree diversity in tropical rainforest are largely unknown. In this study, selectively logged tropical rainforest in Indonesian Borneo is shown to contain high tree species richness, despite severe structural damage. Plots logged 8 years before sampling contained fewer species of trees greater than 20 centimeters in diameter than did similar-sized unlogged plots. However, in samples of the same numbers of trees (requiring a 50 percent larger area), logged forest contained as many tree species as unlogged forest. These findings warrant reassessment of the conservation potential of large tracts of commercially logged tropical rainforest

Amphibians share several biological characteristics that may cause them to be sensitive to abrupt transitions in microhabitat and microclimate that occur across forest edges. To better understand the importance of edge effects on amphibians in a forested landscape, we sampled the distribution of populations along drift fences placed perpendicular to silvicultural edges of varying contrast in central Maine. Within the community of amphibians sampled (14 species), salamanders generally were more sensitive to even-aged harvesting and associated edge effects than were anurans, but forest habitat generalists and specialists were identified within both groups. We conservatively estimated the depth of edge effects at 25-35 m for a subset of management-sensitive species (Plethodon cinereus, Ambystoma maculatum, A. laterale, and Rana sylvatica). An index of edge contrast, calculated using ambient light penetration levels, was valuable in predicting the magnitude of edge effects among sites that included silvicultural edges of different age and origin (old field plantations versus recent clearcuts). Some structural microhabitat variables relevant to forest management were identified as potentially limiting to amphibians near forest edges, including canopy cover, litter cover, and a measure of stumps, snags, and their root channels. Our observations are consistent with the results of other work on biotic edge effects in the eastern United States and suggest that impacts from intensive forest management practices extend beyond the boundaries of harvested stands.

With the exception of the tropics, nowhere has the relationship between resource management and conservation of biological diversity been more controversial than in the Pacific Northwest region of the United States. Widespread loss and fragmentation of old-growth ecosystems have stimulated critical review and revision of existing forest management policies. However, studies of the consequences of forest management for plant species diversity are sorely lacking. We present data from permanent-plot and chronosequence studies in managed and unmanaged forests of western Oregon and Washington to describe the early responses of understory communities to forest harvest, and to suggest how post-harvest practices that alter natural successional processes may influence long term patterns of diversity and species occurrence. Permanent-plot studies of early succession in old-growth Pseudotsuga forests suggest that changes in understory diversity are fairly short-lived following clear-cut logging and slash burning. Populations of most vascular plant species recover to original levels prior to canopy closure. However, diversity may remain depressed for more than two decades on severely burned sites, and some species may experience local extinction. Evidence of the effects of post-harvest practices on vascular plant diversity is limited by an absence of community-level studies in older, managed forests. Chronosequence studies of natural forest stands indicate that, following canopy closure, vascular plant species diversity tends to increase with time, peaking in old growth. Few understory species are restricted to, or absent from, any stage of stand development (i.e., young, mature, or old growth). However, many species differ significantly in their abundance among stages. A majority of these showed greatest abundance in old growth. Changes in levels of resources (increased shade), changes in the spatial variability of resources and environments (increased horizontal and vertical heterogeneity), and species' sensitivity to fire and slow rates of reestablishment/growth may drive these trends during natural stand development. Silvicultural prescriptions that maintain or foster spatial and temporal diversity of resources and environments will be most effective in maintaining plant species diversity. Practices associated with intensive, short-rotation plantation forestry, that preclude or delay the development of old-growth attributes, may result in long-term loss of diversity. Ultimately, it may be necessary to manage some stands on long rotations (150-300 yr) to maintain understory species that require long periods to recover from disturbance.

Fragmentation can alter the ecology of rain forest remnants in many ways, but its long-term effects on tree communities are poorly understood. One phenomenon that has received little attention is tree regeneration in fragmented forests. Patterns of regeneration are important because they will ultimately determine the floristic composition of the remnant. Janzen (1983) suggested that fragments of tropical dry forest in Costa Rica are prone to invasions of weedy, generalist plant species from the surrounding modified matrix, which could progressively alter the floristic composition of remnants. Laurance (1991, 1997) proposed that fragments in some tropical regions are chronically disturbed by winds and other factors and may exhibit a general shift toward successional trees, lianas, and vines adapted for recurring disturbance. Using data collected over 13 years, we describe patterns of tree recruitment in a fragmented landscape in central Amazonia. We ask three questions: (1) Do rates of tree recruitment differ between fragmented and continuous forests? (2) Are recruitment rates influenced by fragment area, age, and proximity of forest edge? (3) Are regenerating trees in fragments biased toward successional species or against old-growth species?