Hydrological effects of tree invasion on a dry coastal Hawaiian ecosystem

FOREST ECOLOGY AND MANAGEMENT

卷:458

Article

Dudley, B. D.^1,7  Hughes, R. F.²  Asner, G. P.³  Baldwin, J. A.⁴  Miyazawa, Y.⁵  Dulaiova, H.⁶  Waters, C.⁶  Bishop, J.⁶  Vaughn, N. R.³  Yeh, J.¹  Kettwich, S.¹  Mackenzie, R. A.²  Ostertag, R.¹  Giambelluca, T.⁵ 

[1] Univ Hawaii, Dept Biol, 200 West Kawili St, Hilo, HI 96720 USA

[2] US Forest Serv, Inst Pacific Isl Forestry, USDA, 60 Nowelo St, Hilo, HI 96720 USA

[3] Arizona State Univ, Ctr Global Discovery & Conservat Sci, 1001 S McAllister Ave, Tempe, AZ 85281 USA

[4] US Forest Serv, Pacific Southwest Res Stn, USDA, Albany, CA 94706 USA

[5] Univ Hawaii Manoa, Dept Geog, Honolulu, HI 96822 USA

[6] Univ Hawaii, Dept Geol & Geophys, 1680 East West Rd, Honolulu, HI 96822 USA

[7] Natl Inst Water & Atmospher Res, 10 Kyle St, Christchurch 8011, New Zealand

关键词: LiDAR;    Transpiration;    Groundwater;    Remote sensing;    Isoscape;    Riparian;   

DOI  :  10.1016/j.foreco.2019.117653

来源: Elsevier

【 摘 要 】

In ecosystems invaded by non-native plants invasion effects are often spatially variable, and this variability is difficult to capture via plot-scale sampling. We used airborne high-resolution LiDAR (Light Detection and Ranging) to generate spatially explicit and contiguous information on hydrological effects of invasive trees (Prosopis pallida (Humb. & Bonpl. ex Willd.) Kunth). We developed regression relationships between LiDAR metrics (i.e., ground elevation and tree canopy height) and plot-scale measurements of vegetation stem water delta O-18, to assess groundwater use, and transpiration rates. We used electrical resistivity imaging to assess subsurface geology and hydrology and their relationships to P. pallida stand structure. P. pallida biomass and transpiration varied greatly across the study area; both were controlled by depth to groundwater. Stem water delta O-18 values (-8.6 to 3.7 parts per thousand) indicated a threshold ground elevation of ca. 15 m above sea level, above which P. pallida could not access groundwater; this threshold corresponded to declines in tree biomass and height. Transpiration modelled across the study area was 0.034 +/- 0.017 mm day(-1), but over 98% of transpiration came from the ca. 25% of the total study area where groundwater depths were less than 15 m. Our combination of methods offers a new way to incorporate fine-scale spatial variation into estimation of plant invasion effects on hydrology, increase our understanding of interactions of geology, hydrology, and biology in such invasions, and prioritise areas for control in well-advanced invasions.

【 授权许可】

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