Effects Of Wind Exposure Research Articles

Effects of Wind Exposure and Deficit Irrigation on Vegetative Growth, Yield Components and Berry Composition of Malbec and Cabernet Sauvignon.

The impact of global warming on Argentine viticulture may result in a geographical shift, with wine-growing regions potentially moving towards the southwest, known as one of the windiest regions in the world. Deficit irrigation is a widely used strategy to control the shoot growth and improve fruit quality attributes, such as berry skin polyphenols. The present study aimed to assess the effects of different wind intensities and irrigation levels, as well as their interactions, on field-grown Vitis vinifera L. cvs. Malbec and Cabernet Sauvignon. The experiment was conducted during two growing seasons with two wind treatments (sheltered and exposed) and two irrigation treatments (well-watered and moderate deficit irrigation) in a multifactorial design. Vegetative growth, stomatal conductance, shoot biomass partition, fruit yield components and berry skin phenolics were evaluated. Our study found that, generally, wind exposure reduced vegetative growth, and deficit irrigation increased the proportion of smaller berries within the bunches. Meanwhile, deficit irrigation and wind exposure additively increased the concentration of berry skin phenolics. Combined stressful conditions enhance biomass partition across the shoot to fruits in Malbec, increasing the weight of bunches and the number of berries. Our findings offer practical implications for vineyard managers in windy regions, providing actionable insights to optimize grapevine cultivation and enhance wine quality.

The Effects of Wind Exposure on Scots Pine Trees: Within-Stem Variability of Wood Density and Mechanical Properties

Survival in variable conditions of wind exposure depends on the strategy of trees in adapting to environmental constraints. There are many studies investigating the effect of wind on the adaptation of trees, but little attention is paid to the properties of the wood, particularly within-stem variability. In the present work, an analysis was made of within-stem variability of the density and mechanical properties of Scots pine wood from parts of stands with different wind exposure (stand edge, forest interior). The research was carried out in north-western Poland, in seven selected pine stands (without other species in the canopy) aged from 82 to 87 years. In each stand, three trial plots were marked, each at a different distance from the edge of the stand. The first plot was immediately adjacent to the edge (0–20 m), the second was at a distance of 30–50 m, and the third was at a distance of 60–80 m. Generally, wind exposure, defined by the distance from the windward edge, did not significantly affect the tree morphology and wood properties. A statistically significant difference was found only for the modulus of elasticity (MOE), between stand edge and forest interior. Trees growing at a distance from the stand edge compensate for their greater stem slenderness with higher elasticity. A certain growth response to wind loads is also represented by the within-stem variability of wood. We found that within-stem variability of wood at the stand edge is higher than in the forest interior. At various points along the stem, the wood density and strength were generally higher on the eastern radius (on the leeward side of the stem). Different wind resistance requirements at the stand edge and in the interior lead to combinations of tree architecture and wood properties that enable the best resistance to wind loads.

The Effect of Wind Exposure on the Web Characteristics of a Tetragnathid Orb Spider

Studies on spiders in their natural habitats are necessary for determining the full range of plasticity in their web-building behaviour. Plasticity in web design is hypothesised to be important for spiders building in habitats where environmental conditions cause considerable web damage. Here we compared web characteristics of the orb spider Metellina mengei (Araneae, Tetragnathidae) in two different forest habitats differing in their wind exposure. We found a notable lack of differences in web geometry, orientation and inclination between webs built along an exposed forest edge and those built inside the forest, despite marked differences in wind speed. This suggests that M. mengei did not exhibit web-building plasticity in response to wind in the field, contrasting with the findings of laboratory studies on other species of orb spiders. Instead, differences in prey capture and wind damage trade-offs between habitats may provide an explanation for our results, indicating that different species employ different strategies to cope with environmental constraints.

Wind as an Abiotic Factor of Colorado Potato Beetle (Coleoptera: Chrysomelidae) Flight Take-Off Activity Under Field Conditions

The flight take-off activity of Colorado potato beetles, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), was significantly higher at a landscape-protected than at semiexposed and exposed sites in a 2-yr field study. In both years, mean daylight temperature, solar radiation, and relative humidity were generally similar at all sites, but wind speed was lower at the protected site than at the exposed sites. Results suggest that wind was the limiting abiotic factor for flight take-off at the exposed site. Caged beetles exposed to constant wind speeds of 3.4, 4.7, and 7.0 m/s showed a significant corresponding decrease in number of flight take-off. There was no cumulative effect of wind exposure on the readiness of the beetles to fly, suggesting that wind acts as a physical barrier to flight take-off. It should be possible to reduce Colorado potato beetle flight dispersal by selecting fields most exposed to wind over landscape-protected fields when rotating potato, Solanum tuberosum L., crops.

Complex spatial and temporal patterns of littoral benthic communities interacting with water level fluctuations and wind exposure in the littoral zone of a large lake

The spatial and temporal organisation of benthic invertebrate communities was studied in a large oligotrophic lake in central Europe. Three shallow littoral sites at 0.4 m depth were sampled monthly from May 2002 to April 2003. On a spatial scale, the benthic community composition at all sites and in all samplings significantly differed in both abundance and biomass. On a temporal scale, the benthic communities at all sites gradually changed each month; monthly samples always significantly differed, but samples from consecutive months were more similar to each other than to samples of non-consecutive months. The observed variability within benthic communities corresponded with changes in the abiotic parameters water level and wind exposure, but was best explained by short- and long-term fluctuations in the water level. Effects of wind exposure were most pronounced in the winter months, when high wind events most often occurred. However, wind effects were masked by stronger effects, such as water-level fluctuation within the shallow littoral zone, or diminished by parameters with opposite effects, e.g. slope vs. exposure. Wind-induced shear stress in the upper eulittoral zone directly influenced the abundance and biomass of the benthic community to a lesser extent. We conclude, however, that this stress alters habitats constantly (e.g. substrate composition, periphyton growth, resuspension vs. sedimentation) and is therefore the driving force for the reported permanent site differences. Furthermore, benthic communities were well adapted to frequent minor changes and also to regular major changes of their habitat, as bare substrates were rapidly recolonised within a month.

The effect of wind exposure on the tree aerial architecture and biomechanics of Sitka spruce (Picea sitchensis, Pinaceae)

This paper reports on the effect of wind loading below damaging strength on tree mechanical and physical properties. In a wind-exposed Sitka spruce stand in western Scotland, 60 trees at four different levels of wind exposure (10 m, 30 m, 50 m, 90 m from edge) were characterized for stem and crown size and shape and mechanical properties, including structural Young's modulus (E(struct)), natural frequency, and damping ratio. E(struct) increased from the stand edge to the mid-forest, but with a large inter-tree variation. Swaying frequency and damping ratio of the trees also increased with distance from edge. Wind-exposed edge trees grew shorter, but more tapered with an overall lower E(struct), allowing for greater flexural stiffness at the stem base due to the larger diameter and for higher flexibility in the crown region of the stem. The trees at the middle of the stand compensated for their increased slenderness with a higher E(struct). Thus, for the different requirements for wind-firmness at stand edge and mid-forest, an adapted combination of tree form and mechanical properties allows the best withstanding of wind loads. The results show the requirement to understand the different strategies of trees to adapt to environmental constraints and the heterogeneity of their growth reactions in response to these strategies.

Windthrow in riparian buffer strips: effect of wind exposure, thinning and strip width

This paper discusses the effects of topography, riparian buffer strip width and thinning on the amount of windthrow over 9 years in balsam fir ( Abies balsamea) stands. Monitoring of windthrow was conducted in 25 riparian areas representing five treatments: uncut control, thinned 20 m strip, unthinned 20, 40 and 60 m strips. Wind tunnel measurements were made on a topographical model of the study area to provide an estimate of local wind behaviour. A cluster analysis performed on the wind speed data led to the identification of four major topographic units of similar wind behaviour. Wind speed in valleys varied greatly depending upon the direction of the approaching winds and the presence of small topographic features. When the wind blows perpendicularly to the valley, wind speed tends to be lower but more variable than when it blows parallel to the valley. Windthrow was not related to strip width or thinning. The field study showed that windthrow 5 years after cutting was found to be correlated with the speed of winds blowing roughly perpendicular to the strips. Windthrow after 7 and 9 years, following an unusual wind event that occurred between years 5 and 7, was no longer correlated with this wind direction. High levels of damage were observed where the valley widened, offering less shelter to the buffer strips.

The effect of wind exposure and filamentous algae on the distribution of surf zone macroinvertebrates in Lake Esrom, Denmark

Distribution and composition of the epilithic macroinvertebrate fauna was studied on 21 different sites situated in the surf zone of Lake Esrom. A relative degree-of-exposure (windinduced wave activity) was calculated for each station from the specific number of wind days, wind velocity and a measured wind fetch. Macroinvertebrate abundance averaged 20 200 ind. m−2 stone bottom, and was composed primarily of six taxa (70% of the mean densities). The distribution patterns of the 48 most common taxa were compared to exposure, the amount of filamentous algae and shore slope, by regression, cluster analysis and ordination analysis (PCA and RDA). The abundance of 25 taxa was significantly correlated to the amount of filamentous algae, and a protectional effect of algae growth was suggested for the exposed sites. Seventeen taxa showed significant difference in abundance between sheltered western stations and exposed eastern stations. Stations with a gentle slope were characterised by sand covered stones and a fauna that qualitatively was similar to the fauna at greater depth in the littoral. Redundancy analysis (RDA) showed filamentous algae and slope to be the most important factors controlling the species distribution, whereas the gradient of exposure in Lake Esrom was too short to explain the species tolerance range.