Spatiotemporal patterns of rising annual plant abundance in grasslands of the Willamette Valley, Oregon (USA)

Context: Plant communities are undergoing compositional changes that affect ecosystem function. These changes are not always uniform across the landscape due to heterogenous topographic and edaphic conditions. To predict areas most at risk of change, it is necessary to identify the landscape drivers affecting plant abundance.
Objectives: Annual plants are increasing across the Wwestern USA, largely driven by non-native annual invasions. Here, we quantified change in annual plant abundance and identified landscape factors contributing to that change over the past 35 years.
Methods: We focused on Willamette Valley (Oregon) grasslands because they represent a new example in this phenomenon. To understand the spatiotemporal patterns of annual plant abundances between 1986 and 2020, we combined a remote-sensing vegetation cover dataset from the rangeland analysis platform with gridded soils data and topographic variables. We determined the rate of change in percent cover for e..., df_RAP.csv: Yearly (1986-2020) vegetation cover data of annual and perennial forbs and grasses for the Willamette Valley were downloaded as TIFF files (30-m resolution) from the Rangeland Analysis Platform's Google Earth Engine catalog. To eliminate forested and other non-grassland areas, we masked RAP data to grassland/herbaceous, pasture/hay, and shrub/scrub classifications in the National Land Cover Database 2019 Land Cover dataset using the raster package in R. Prior to this, we had previously resampled the land cover dataset from 10-m to 30-m resolution and reprojected to WGS 1984 using ArcMap 10.5. For each year in the 1986-2020 RAP dataset, we calculated new rasters for total herbaceous cover by summing the annual and perennial layers. We then filtered to cells with ≥20% average total herbaceous cover across the 35 years to avoid areas which may have skewed estimates due to low herbaceous cover in general (e.g., grassland borders near forests). Finally, we filtered to the 16 site..., , , # Data from: Spatiotemporal patterns of rising annual plant abundance in grasslands of the Willamette Valley, Oregon (USA)

This README file from: Spatiotemporal patterns of rising annual plant abundance in grasslands of the western Pacific Northwest, USA, was generated on 2022-07-06 by Paul B. Reed

#### GENERAL INFORMATION

1. Title of Dataset: Data from: Spatiotemporal patterns of rising annual plant abundance in grasslands of the western Pacific Northwest, USA
2. Author Information
A. Principal Investigator Contact Information
Name: Paul B. Reed
Institution: Institute for Applied Ecology
Address: 4950 SW Hout St
Corvallis, OR 97333
Email: [[e-mail]](mailto:[e-mail])
3. Date of data collection: 2022-02-01
4. Geographic location of data collection: Willamette Valley, Oregon, USA
5. Information about funding sources that supported the collection of the data:
USDA-NIFA postdoctoral fellowship award # 2021-67034-35136

#### SHARING/ACCES...