December 2012 Number 1 - Utah Native Plant Society

More documents

Recommendations

Info

Utah Native Plant Society Figure 2. Vegetation community type map of the Ash Meadows National Wildlife Refuge. 80
Calochortiana December 2012 Number 1 sima) and Russian knapweed (Acroptilon repens) found throughout Carson Slough, as well as in the parceled wet meadows created adjacent to Rogers Spring where spring water once flowed unobstructed into the slough. The Refuge is in the habitat restoration stage and will remain so for many years. Goals of the restoration plan include restoring natural hydrology and native vegetation communities, establishing a baseline of existing vegetation communities, and managing and recovering rare and endangered species occurring on the Refuge (McKelvey 2007). The U.S. Fish and Wildlife Service is conducting long-range, strategic management and restoration planning at AMNWR to accomplish the recovery goals of ecosystem and species restoration. The recovery objective for the Refuge is: “delisting for all species but the Devil’s Hole pupfish, which can only be downlisted to threatened status” (Sada 1990). PRELIMINARY VEGETATION MAPPING AND CLASSIFICATION The consulting firm BIO-WEST, Inc. undertook two studies designed to assist the AMNWR with its restoration efforts. The first study involved mapping all vegetation communities to a fine scale (0.25 acres), with the objective of providing a baseline data set for evaluation of management actions and future vegetation change, while the second included a comprehensive survey of distribution and abundance for twelve rare plant species. Completion of vegetation mapping on the Refuge has resulted in 6,237 delineated polygons (Figure 2). Of the delineated polygons, 5,913 (or 95 percent) have been assigned a preliminary alliance. Alliance assignments will be referred to as preliminary until classification is finalized. These classifications are being derived from multiple sources including Alliances of the Mojave Desert (USGS 2004), the National Vegetation Classification System (Grossman et al. 1998), and community data available on NatureServe (USGS 2004). As currently assigned, the alliances comprising the highest total acreage on the Refuge are the Atriplex confertifolia Shrubland Alliance, the Larrea tridentata- Ambrosia dumosa Shrubland Alliance, and the Isocoma acradenia Shrubland Alliance. Several delineated vegetation communities do not correspond to any previous classifications. Often this is the result of a Refuge community that has a typical dominant species occurring with an atypical co-dominant. An example of this is the Atriplex confertifolia Shrubland Alliance compared with the Atriplex confertifolia-Suaeda moquinii Shrubland Alliance. The first is a common community throughout the desert southwest. However, communities with both Atriplex confertifolia and Sueda moquinii occurring as co-dominants have not been classified. In these cases a new alliance classification may be written to best represent the vegetation community. Once final classifications have been assigned, botanical descriptions will be developed for each of the newly created alliances. Association classifications are also currently in the developmental stage. Many of the common botanical associations are applicable to communities at the Refuge. However, a significant number of the delineated polygons contain associations of plants that are not commonly recognized in current classifications. These associations are being thoroughly researched in order to identify appropriate resources for classification assignments. As with the alliance classifications, we expect to develop several new association classifications to accurately describe the communities at the Refuge (BIO- WEST 2008). The vegetation mapping effort has resulted in a clearer picture of the diverse composition of vegetation communities that exist within AMNWR (Figure 2). Common vegetation communities that have been identified include Alkali Sink (an extensive shrubland community dominated by succulent shrubs such as Mojave seablite, [Suaeda moquinii] that occur adjacent to seasonally flooded wetlands and along desert washes), as well as a variety of wetland communities. Lowland Riparian Woodlands are found in the lowest elevations of the Refuge; they support a variety of canopy species such as velvet ash (Fraxinus velutina), mesquite (Prosopis), and narrow-leaf willow (Salix exigua). One of the more unique community types is the Alkali Playa community found west of Crystal Reservoir and Lower Marsh. This community may support the largest populations of rare and endemic plants on the Refuge. The western portion of the Refuge also supports well-established populations of salt cedar, Russian knapweed, and five-hook bassia (Bassia hyssopifolia). The salt cedar communities function as riparian woodlands and in some cases may provide important wildlife habitat. Several of the abandoned agricultural fields have been infested with five-hook bassia. However, these fields currently receive enough seasonal inundation to sustain recruiting populations of native wetland vegetation. Fairly intact transitional Upland and Desert Shrubland communities are present in the central and eastern portions of the Refuge. The Alkali Shrub community type transitions from a mesic phase as the topography rises in elevation from west to east. A noticeable change in vegetation composition occurs as whiteflower rabbitbrush (Chrysothamnus albidus)-dominated communities become replaced by alkali goldenbush (Isocoma acradenia) in the higher elevations where the water table is less accessible. Moving up into the alluvial fans, what was once classified as part of Creosote Shrubland is now classified as Salt Desert Shrubland composed of desert holly (Atriplex hymenelytra), shad- 81
Page 1 and 2:
Calochortiana December 2012 Number
Page 3 and 4:
Page 5 and 6:
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30: Calochortiana December 2012 Number
Page 67 and 68: Species # Training Samples Calochor
Page 79: Calochortiana December 2012 Number
Page 97 and 98: case of the former lake beds a duri
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
A. lentiginosus var. ursinus (publi
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190:
Page 191 and 192:
Page 193 and 194:
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201 and 202:
Page 203 and 204:
Page 205 and 206:
Page 207 and 208:
Page 209 and 210:
Pot Score Min Score Trend Threat In
Page 211 and 212:
Page 213 and 214:
Page 215 and 216:
Page 217 and 218:
Page 219 and 220:
Page 221 and 222:
Page 223 and 224:
Page 225 and 226:
Page 227 and 228:
Page 229 and 230:
Page 231 and 232:
Page 233 and 234:
Page 235 and 236:
Page 237 and 238:
show all

December 2012 Number 1 - Utah Native Plant Society

Create successful ePaper yourself

Delete template?

Save as template?