Author
Davies, Kirk | |
Bates, Jonathan - Jon | |
MILLER, RICHARD - OREGON STATE UNIV |
Submitted to: Ecological Society of America Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 6/1/2004 Publication Date: 8/1/2004 Citation: Davies, K.W., Bates, J.D., Miller, R.F. 2004. Vegetation potentials of wyoming big sagebrush communities: are vegetation guidelines for sage grouse realistic? Ecological Society of America Abstracts. p. 118. Interpretive Summary: The Wyoming big sagebrush (Artemisia tridentata ssp. Wyomingensis, ARTRWY) cover type is the most extensive of the big sagebrush complex in the Intermountain West. Sage-grouse habitat guidelines, based upon plant cover, have recently been developed for sagebrush communities in Oregon. Plant ecologists have questioned the appropriateness and applicability of the guidelines in ARTRWY communities. There is a lack of information regarding the range, variability, and potential of vegetation characteristics describing the ARTRWY communities. Our objectives were to; 1) described vegetation/soil characteristics at the stand level and develop a community classification system for the ARTRWY cover type; and 2) compare stand level cover characteristics with sage grouse habitat cover guidelines. We intensively sampled 107 high ecological condition sites across 4 ecological provinces in eastern Oregon. Using multivariate analysis, differences in functional group cover and species composition indicated that grouping ARTRWY communities by dominant grass species associations was appropriate. Thus, 6 ARTRWY community associations were identified. Using a strict interpretation of the suggested guidelines, none met sage grouse nesting and brood rearing habitat requirements. The main reason for not meeting guideline requirements is that tall forb (plants < 18 cm tall) cover did not equal or exceed 10% cover. Only 32 sites (less than 30%) met the sub-optimum brood rearing habitat guideline requirements. The winter habitat guideline requirements were met by 75 of the sites. Individual associations within the Wyoming big sagebrush cover type varied in their ability to meet sub-optimum brood rearing and winter habitat requirements. The limited potential of the Wyoming big sagebrush alliance to meet nesting and optimum brood rearing habitat requirements cautions against adopting current guidelines to direct management decisions in our region. Technical Abstract: The Wyoming big sagebrush (Artemisia tridentata ssp. Wyomingensis, ARTRWY) cover type is the most extensive of the big sagebrush complex in the Intermountain West. Sage-grouse habitat guidelines, based upon plant cover, have recently been developed for sagebrush communities in Oregon. Plant ecologists have questioned the appropriateness and applicability of the guidelines in ARTRWY communities. There is a lack of information regarding the range, variability, and potential of vegetation characteristics describing the ARTRWY communities. Our objectives were to; 1) described vegetation/soil characteristics at the stand level and develop a community classification system for the ARTRWY cover type; and 2) compare stand level cover characteristics with sage grouse habitat cover guidelines. We intensively sampled 107 high ecological condition sites across 4 ecological provinces in eastern Oregon. Using multivariate analysis, differences in functional group cover and species composition indicated that grouping ARTRWY communities by dominant grass species associations was appropriate. Thus, 6 ARTRWY community associations were identified. Using a strict interpretation of the suggested guidelines, none met sage grouse nesting and brood rearing habitat requirements. The main reason for not meeting guideline requirements is that tall forb (plants < 18 cm tall) cover did not equal or exceed 10% cover. Only 32 sites (less than 30%) met the sub-optimum brood rearing habitat guideline requirements. The winter habitat guideline requirements were met by 75 of the sites. Individual associations within the Wyoming big sagebrush cover type varied in their ability to meet sub-optimum brood rearing and winter habitat requirements. The limited potential of the Wyoming big sagebrush alliance to meet nesting and optimum brood rearing habitat requirements cautions against adopting current guidelines to direct management decisions in our region. |