[PCA] Science-based guidelines for restoration and conservation of sagebrush ecosystems

[De Angelis, Patricia]

This recently-published paper by some of the preeminent Forest Service
researchers on the topic provides important insights on using
ecologically-appropriate plants to restore sage brush ecosystems.

According to Science Program Manager Deborah Finch, U.S. Forest
Service, the paper reports that, based on genetics testing matched with
seed weights, sagebrush seed mixes commonly used to restore burned areas in
the Great Basin are sometimes using the wrong subspecies seed which might
in part explain why restoration of burned sites fails.  We think the
research findings in the paper are big news because they have the potential
to influence seed-collecting policy for commercial seed producers and
agency users of commercial seed mixes.

Genetic and environmental effects on seed weight in subspecies of big
sagebrush: applications for restoration
Richardson et al. 2015
Ecosphere 6(10): Article 201:1-13.

Abstract:
The sagebrush steppe is a patchwork of species and subspecies occupying
distinct environmental niches across the intermountain regions of western
North America. These ecosystems face degradation from disturbances and
exotic weeds. Using sagebrush seed that is matched to its appropriate niche
is a critical component to successful restoration, improving habitat for
the threatened greater sage-grouse and other species. The need for
restoration is greatest in basin habitats composed of two subspecies:
diploid basin big sagebrush (A. tridentata subsp. tridentata) and
tetraploid Wyoming big sagebrush (subsp. wyomingensis). In this study we
assess seed weights across five subspecies-cytotype groups of big sagebrush
and examine the genetic and environmental components. Our goal is to
determine if seed weight can be used as a diagnostic test for subspecies
and seed certification. Seed weight was measured from 55 wild collections
and from progeny derived from these collections and grown in two common
gardens. A linear mixed-effect model showed 91% of the variation in seed
weight is explained by genetic, genetic × environment and environmental
effects (conditional R2 = 0.91). Moreover, genetic effects alone,
subspecies-cytotype groups, explained 39% of the variation (marginal R2 =
0.39). Of the five subspecies-cytotype groups, most had overlapping weights
using conservative 99% confidence intervals. However, diploid tridentata
and wyomingensis had non-overlapping 99% confidence intervals. To
demonstrate the application of seed weighing to assess the subspecies
purity of commercial seed lots, we compared confidence intervals of
tridentata and wyomingensis developed from the experimental data to seed
weights of commercial lots. The results showed that only 17% of the
commercial seed lots certified as wyomingensis had mean seed weights that
fell within the confidence intervals for this subspecies. The remaining
lighter seed lots (83%) matched weights of tridentata. While restoring
sagebrush ecosystems is a multifaceted problem, a fundamental component to
restoration is ensuring the appropriate seed is used. We found seed weight
is principally affected by genetic factors, with limited environmental
effects. Seed weighing is an effective application to assess subspecies
purity of wyomingensis and tridentata seed and could be used as a
certification step for evaluating commercial collections used in
restoration.

Summary:
http://www.fs.fed.us/rmrs-beta/science-spotlights/science-based-guidelines-restoration-and-conservation-sagebrush-ecosystems
?

Spotlight on Research Geneticist Bryce Richardson (provides links to the
journal papers):
http://www.fs.fed.us/rmrs-beta/science-spotlights/science-based-guidelines-restoration-and-conservation-sagebrush-ecosystems


Pardon cross-postings.

Patricia S. De Angelis, Ph.D.
Botanist, Division of Scientific Authority
US Fish & Wildlife Service
5275 Leesburg Pike, MS: IA
Falls Church, VA 22041-3803
703-358-1708 x 1753
703-358-2276 (FAX)
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