Hydrologic Response of Meadow Restoration the First Year Following Removal of Encroached Conifers

Christopher Surfleet,Gregory Vanoosbree,John Jasbinsek,Thomas Sanford

doi:10.3390/w11030428

Abstract

This study examines the hydrologic response of a montane meadow the first winter following restoration by removal of encroached conifers. Hydrologic change was evaluated through statistical comparison of soil moisture and water table depths between the restored meadow, Marian Meadow, and a Control Meadow before and after restoration. Meadow water budgets and durations of water table depths during the growing season were evaluated. Electrical resistivity tomography profiles were collected to improve the spatial interpretation of subsurface water beyond well measurements. The first year following restoration Marian Meadow had a statistically significant increase in volumetric soil moisture content of 4% with depth to the water table decreasing on average by 0.15 m. The water budget for the meadows demonstrated that the hydrologic change following removal of encroached conifers was primarily due to a reduction of vegetation interception capture. Soil evapotranspiration rates in both the Control and Marian Meadows were relatively stable ranging from 268–288 mm/yr with the exception of the year following conifer removal in Marian Meadow with 318 mm/yr. The increase in soil evapotranspiration in the first post restoration year is attributed to loss of vegetation cover and higher proportions of bare soil created from the harvest operations. The duration of post-restoration water table depths during the growing season at Marian Meadow were less than or equal to 0.7 m and 0.3 m for 85 days and 50 days, respectively, indicating hydrologic conditions conducive to meadow vegetation.

Highlights

Meadows are a small but important component of forested ecosystems in temperate climates.They provide critical habitat for many species of plants and animals [1,2,3] and play an important role in improving water quality, flood protection, and carbon storage [4]
The mean Control Meadow and Marian Meadow soil moisture content prior to and following restoration were statistically different from one another (P value < 0.0001) (Figures 5 and 6)
The intercept and slope of Marian Meadow soil moisture content pre- and post-restoration regression lines were statistically different from one another (P value < 0.0001) (Figure 5)

Summary

Introduction

Meadows are a small but important component of forested ecosystems in temperate climates. They provide critical habitat for many species of plants and animals [1,2,3] and play an important role in improving water quality, flood protection, and carbon storage [4]. Nevada and Cascade mountain meadows have reduced in size and number in part due to conifer encroachment. Temperate forest regions in Europe and Canada have seen declines in montane meadows due to conifer encroachment [5,6]. There is little information on the hydrologic effect of removing encroached conifers for meadow restoration. Conifer encroachment ( referred to as invasion) refers to the migration of conifers into meadow biotic communities. In the western United States, encroachment is typically by an influx of

Methods

Results

Discussion

Conclusion