Characteristics of some organised structures in the turbulent wind above and within a spruce forest from field measurements

Boldes, Ulfilas; Scarabino, Ana Elena; Leo, Julio Marañón Di; Colman, J.; Gravenhorst, G.

doi:10.1016/s0167-6105(03)00076-x

Cited by 9 publications

(3 citation statements)

References 23 publications

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“…The probability density functions were mostly distributed over 0-30 s with a maximum in the 10-20 s bin, at both heights. The result agreed well with the observed typical duration of canopy coherent motions, 10-20 s by Boldes et al (2003) and 22 s by Thomas et al (2006). While Boldes et al (2003) have observed another energetic scale at 160 s, such large-scale eddies were absent in our results.…”

Section: Vertical Motionsupporting

confidence: 93%

Stability Dependence of Canopy Flows over a Flat Larch Forest

Kobayashi

Hiyama

2011

Boundary-Layer Meteorol

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The dependence on atmospheric stability of flow characteristics adjacent to a very rough surface was investigated in a larch forest in Japan. Micrometeorological measurements of three-dimensional wind velocity and air temperature were taken at two heights above the forest, namely 1.7 and 1.2 times the mean canopy height h. Under near-neutral and stable conditions, the observed turbulence statistics suggest that the flow was likely to be that of the atmospheric surface layer (ASL) at 1.7h, and of the roughness sublayer (RSL) at 1.2h. However, in turbulence spectra, canopy-induced large coherent motions appeared clearly at both heights. Even under strongly stable conditions, the large-scale motions were retained at 1.2h, whereas they were overwhelmed by small-scale motions at 1.7h. This phenomenon was probably due to the enhanced contribution of the ASL turbulence associated with nocturnal decay of the RSL depth, because the small-scale motions appeared at frequencies close to the peak frequencies of well-known ASL spectra. This result supports the relatively recent concept that canopy flow is a superimposition of coherent motions and the ASL turbulence. The large-scale motions were retained in temperature spectra over a wider region of stability compared to streamwise wind spectra, suggesting that a canopy effect extended higher up for temperature than wind. The streamwise spacing of dominant eddies according to the plane mixing-layer analogy was only valid in a narrow range at near neutral, and it was stabilised at nearly half its value under stable conditions.

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Section: Vertical Motionsupporting

confidence: 93%

Stability Dependence of Canopy Flows over a Flat Larch Forest

Kobayashi

Hiyama

2011

Boundary-Layer Meteorol

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“…If forested areas had favourable structure and composition which minimizes significant hurricane damage, such areas should buffer the negative impacts associated with hurricane force winds. Wind speed and mixing dynamics differ relative to vertical structure of vegetation such that wind speeds are typically lower at the mid-story or ground level (2 m off ground, [78]). Thus, animals in forested areas can experience wind loads as low as one half of those experienced by animals in open environments [79], suggesting forests should offer relatively more protection from hurricane force winds than open areas.…”

Section: Discussionmentioning

confidence: 99%

Deer movement and resource selection during Hurricane Irma: implications for extreme climatic events and wildlife

et al. 2019

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Extreme climatic events (ECEs) are increasing in frequency and intensity and this necessitates understanding their influence on organisms. Animal behaviour may mitigate the effects of ECEs, but field studies are rare because ECEs are infrequent and unpredictable. Hurricane Irma made landfall in southwestern Florida where we were monitoring white-tailed deer ( Odocoileus virginianus seminolus ) with GPS collars. We report on an opportunistic case study of behavioural responses exhibited by a large mammal during an ECE, mitigation strategies for reducing the severity of the ECE effects, and the demographic effect of the ECE based on known-fate of individual animals. Deer altered resource selection by selecting higher elevation pine and hardwood forests and avoiding marshes. Most deer left their home ranges during Hurricane Irma, and the probability of leaving was inversely related to home range area. Movement rates increased the day of the storm, and no mortality was attributed to Hurricane Irma. We suggest deer mobility and refuge habitat allowed deer to behaviourally mitigate the negative effects of the storm, and ultimately, aid in survival. Our work contributes to the small but growing body of literature linking behavioural responses exhibited during ECEs to survival, which cumulatively will provide insight for predictions of a species resilience to ECEs and improve our understanding of how behavioural traits offset the negative impacts of global climate change.

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“…Whilst much of the basic work in this area has been carried out by agronomists and plant scientists, some experimental work looking at tree behaviour in high winds from an engineering perspective has been carried out both by one of the author and his co-workers (Baker and Bell, 1992;Roodbaraky et al, 1994) for urban trees, and by Boldes and his colleagues in Argentina (Boldes et al 2001(Boldes et al , 2002(Boldes et al , 2003 for forest trees and shelterbelts. Computational studies of flows within canopies are also reported by Hiraoka (1993) and Hiraoka and Ohashi (2000).…”

Section: Introductionmentioning

confidence: 99%