Assessing and Mitigating the Effects of Windblown Soil on Rare and Common Vegetation

Abstract

Acting under the auspices of the US Endangered Species Act, we quantified wind erosion and its effects on rare and common plant species on a semi-arid military installation in Hawaii. Our goal was to develop management strategies, based on local data, to aid the conservation of rare and common indigenous plants and their habitats. We collected windblown soil coming off of roads and other disturbed soils to assess likely impacts to plants occurring at certain heights and distances from disturbed surfaces. We then subjected plants in a glasshouse to windblown dust treatments, designed from our field data to simulate erosion events, and evaluated the effect of these treatments on photosynthesis and survival. We also designed several field experiments to examine the in-situ effects of windblown soil and soil substrate on germination, growth rate, and survival of indigenous and nonindigenous plants. We conclude from these experiments that most direct effects of windblown soil to plants can be effectively mitigated by locating roads and training areas at least 40 m from sensitive plant habitats and through vegetation management to maintain at least 11% aerial cover on disturbed surfaces. Effects of soil type on germination, growth, and survival was species-specific, emphasizing the importance of species trials prior to, or during, rehabilitation efforts.

Road Dust Correlated with Decreased Reproduction of the Endangered Utah Shrub Hesperidanthus suffrutescens

“…Though the other measures of reproduction (i.e., number of plant seeds and plant seed weight) were not statistically significant, the overall pattern of decreasing reproduction with increasing dust deposition strongly suggests that dust has a negative impact. Interestingly, Gleason et al (2007) found that windblown soil had no significant impact on either rare or common plants beyond a distance of 40 m from a road in Hawaii. In our study, no plants grew within 100 m of the road, and we found that dust impacted fruit set regardless of distance.…”

Plants and Atmospheric Aerosols

“…They are mostly deposited by wet deposition of fine aerosols (Reisinger 1990;Smith 1990;Adachi and Tainosho 2004;Gleason et al 2007). Near sources of heavy metals, concentrations are high on foliage and in litter, eventually contaminating the soil surface layers.…”