Comparison of visual estimation and line-point intercept vegetation survey methods on annual grass–invaded rangelands of Wyoming

Andrea De Stefano,Brian A. Mealor,Beth Fowers

doi:10.1017/inp.2021.36

Andrea De Stefano, Brian A. Mealor + Show 1 more

Open Access

https://doi.org/10.1017/inp.2021.36

Copy DOI

Abstract

AbstractScientists and natural resource managers require suitable vegetation survey methods to assess the success of rangeland restoration projects. Visual estimation and point intercept methods are commonly used to evaluate vegetation cover. This study compared the performance of one visual (quadrat-based) and two line-point intercept (LPI, canopy and basal) methods to assess biodiversity and cover and to estimate biomass production on sites invaded by introduced annual grasses across Wyoming, USA. Greater species richness and higher Shannon index values were measured in quadrats, while introduced annual and native perennial graminoid cover values were higher in LPI canopy in general. Overall, these outcomes indicate quadrats as the most suitable survey method when biodiversity monitoring is the primary objective, while suggesting LPI canopy when monitoring vegetation cover is prioritized. Finally, our regression models indicated quadrat-based estimates as the most reliable to predict introduced annual and native perennial graminoid biomass.

Highlights

One of the most important components of ecological restoration projects is monitoring of plant communities
Choosing an appropriate monitoring methodology becomes a high-priority decision for scientists and natural resource professionals involved in restoration and adaptive management (Mealor et al 2013)
Results suggested that vegetation survey methods differed in the overall number of species detected, as shown by samplebased species accumulation curves (Figure 3)

Summary

Introduction

One of the most important components of ecological restoration projects is monitoring of plant communities. To track restoration goals, monitoring must rely on dependable sampling techniques capable of reliably and consistently detecting spatial and temporal changes in vegetation structure (Chen et al 2009; Kopecký and Macek 2015; Sutter 1996), with particular attention to vegetation cover, productivity, species richness, and diversity (Elzinga et al 2009; Herrick et al 2005; Seefeldt and Booth 2006). These indicators are closely associated with habitat quality, resilience to invasion, grazing, erosion potential, and climate change (Herrick et al 2012; Pyke et al 2002). Researchers and managers have collaborated to produce standardized protocols to obtain repeatable, statistically defensible, and comparable data (Herrick et al 2010; Wirth and Pyke 2007)

Objectives

Methods

Results