Data from: Multi-decadal vegetation transformations of a New Mexico ponderosa pine landscape after severe fires and aerial seeding
Data files
Dec 01, 2023 version files 438.03 KB
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All_Years_1997-2019_PermPlot-Entire-APW_clean.csv
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README.md
Abstract
Wildfires and climate change are having transformative effects on vegetation composition and structure, and post-fire management may have long-lasting impacts on ecosystem reorganization. Post-fire aerial seeding treatments are commonly used to reduce runoff and soil erosion, but little is known about how seeding treatments affect native vegetation recovery over long periods of time, particularly in type-converted forests which have been dramatically transformed by the effects of repeated, high-severity fire. In this study, we analyze and report on a rare long-term (23-year) dataset that documents vegetation dynamics following a 1996 post-fire aerial seed treatment and subsequent 2011 high-severity reburn in a dry conifer forest of northern New Mexico in the southwestern United States. Repeated surveys between 1997 – 2019 of 49 permanent transects were used to test for differences in vegetation cover, richness, and diversity between seeded and unseeded areas, and to characterize the development of seeded and unseeded vegetation communities through time and across gradients of burn severity, elevation, and soil-available water capacity. Post-fire seeding led to a clear and sustained divergence in herbaceous community composition. Seeded plots had much higher cover of non-native graminoids, primarily Bromus inermis, a likely contaminant in the seed mix. High-severity reburning in all plots in 2011 reduced native graminoid cover by half at seeded plots compared to both pre-fire levels and to plots that were unseeded following the initial 1996 fire. In addition, increased fire severity was associated with increased non-native graminoid cover and reduced native graminoid cover, native species richness, and species diversity. This study documents a fire-driven ecosystem transformation from a former conifer forest into a shrub-grass system, reinforced by aerial seeding of grasses and high-severity reburning. This unique long-term dataset illustrates that post-fire seeding carries significant risk of unwanted non-native species invasions that persist through subsequent fires – indicating that alternative post-fire management actions merit consideration to better support native ecosystem resilience in the face of emergent climate change and increasing disturbance. Lastly, this study highlights the importance of long-term monitoring of post-fire vegetation dynamics, as short-term assessments will miss key elements of the full complexity of ecosystem responses to fire and post-fire management actions.
README: Data from: Multi-decadal vegetation transformations of a New Mexico ponderosa pine landscape after severe fires and aerial seeding
https://doi.org/10.5061/dryad.z612jm6jq
Description of the data and file structure
These data represent 4 samples of a 22 year time period: repeat observations of vegetation cover from the Dome Wilderness in New Mexico, from 1997-2019. Fundamentally, these data represent species and ground cover at a cm-resolution, recorded along 50 meter line intercept transects. The description of column names are as follow:
Transect: Site ID
Year: Sample ID
Code: 4-5 character code relating to species or ground cover category
RevBI: Burn Severity Index as reported by initial BAER estimates
TRT: Treatment - seeded or unseeded
Full_name: Latin name of species or genus, or full name of ground cover category
Origin: Native or Non-native to the Dome Wilderness, NA for ground cover categories
Transect_cm: Total length of the Transect in centimeters
Growth_form: Functional group of plant species, genus, or cover category. Abbreviations are as follow: B - Bare Ground, C - Crypotgram, F- Forbs, G - Graminoids, L - Litter, M - Mushroom or Fungus, S - Shrub, T - Tree, U - SubShrub
PctC: Percent canopy cover of total transect, rounded to nearest 1%
PctC_basal: Percent cover of basal intersection with transect, as opposed to canopy interception (representing a base of an individual plant or otherwise any object embedded in the soil surface)
Total_cm: Combined basal and canopy cover of cover type on transect/year combination
Basal_cm: Basal intersection (embedded in the soil) of cover type on transect/year combination
Canopy_cm: Canopy intersection of cover type on transect/year combination\
FS_BAND: A factor, indicating the land management agency which administers the plot. Either FS - for Forest Service, or BAND for Bandelier National Monument (National Park Service)
The vegetation data collection method followed the line-intercept method (Mueller-Dombois and Ellenberg 1974). Vegetation transects were approximately 50 meters in length and the data collected included herbaceous foliar and basal cover of all live and dead vegetation to the nearest cm. Plants were identified to the species-level, when possible, otherwise plants were grouped by their genus, or unknown plants were grouped by their growth form (see below). This line intercept method records the number of canopy-cover centimeters per species, and therefore allows for overlapping total vegetative canopy cover more than the total transect length. In cases where combined canopy cover for an individual species exceeded 100%, these species values were constrained to 100%. Canopy cover is reported as a proportion of the number of centimeters recording live foliar cover of a given species or growth form relative to the length of the transect. Bare ground is reported as a proportion of exposed soil, measured as the basal gap area between plant bases or other objects embedded in the surface (e.g., logs, rocks, litter) relative to the length of the transect.
Methods
The vegetation data collection method followed the line-intercept method (Mueller-Dombois and Ellenberg 1974). Vegetation transects were approximately 50 meters in length and the data collected included herbaceous foliar and basal cover of all live and dead vegetation to the nearest cm. Plants were identified to the species-level, when possible, otherwise plants were grouped by their genus, or unknown plants were grouped by their growth form (see below). This line intercept method records the number of canopy-cover centimeters per species, and therefore allows for overlapping total vegetative canopy cover more than the total transect length. In cases where combined canopy cover for an individual species exceeded 100%, these species values were constrained to 100%. Canopy cover is reported as a proportion of the number of centimeters recording live foliar cover of a given species or growth form relative to the length of the transect. Bare ground is reported as a proportion of exposed soil, measured as the basal gap area between plant bases or other objects embedded in the surface (e.g., logs, rocks, litter) relative to the length of the transect.