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Vegetation influences on infiltration in Hawaiian soils
Author(s) -
Perkins Kim S.,
Stock Jonathan D.,
Nimmo John R.
Publication year - 2018
Publication title -
ecohydrology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.982
H-Index - 54
eISSN - 1936-0592
pISSN - 1936-0584
DOI - 10.1002/eco.1973
Subject(s) - environmental science , groundwater recharge , soil water , infiltration (hvac) , ecosystem , vegetation (pathology) , hydrology (agriculture) , reforestation , soil science , ecology , agroforestry , aquifer , geology , geography , groundwater , biology , medicine , geotechnical engineering , pathology , meteorology
Abstract Changes in vegetation communities caused by removing trees, introducing grazing ungulates, and replacing native plants with invasive species have substantially altered soil infiltration processes and rates in Hawaii. These changes directly impact run‐off, erosion, plant‐available water, and aquifer recharge. We hypothesize that broad vegetation communities can be characterized by distributions of field‐saturated hydraulic conductivity (K fs ). We used 290 measurements of K fs calculated from infiltration tests from 5 of the Hawaiian Islands to show this effect. We classified the data using 3 broad ecosystem categories: grasses, trees and shrubs, and bare soil. The soils of each site have coevolved with past and present ecological communities without significant mechanical disturbance by agriculture or urban development. Geometric mean values K fs are 203 mm/hr for soils hosting trees and shrubs, 50 mm/hr for grasses, and 13 mm/hr for bare soil. Differences are statistically significant at the 95% confidence level. These examples show that it is feasible to make maps of relative K fs based on field and ecosystem data. These ecosystem trends can be used to estimate ongoing changes to run‐off and recharge from climate and land use change. Greater K fs for ecosystems with primarily trees and shrubs suggests that management decisions concerning reforestation or other changes of vegetation can have substantial hydrologic impacts.