SUPPLEMENTAL MATERIALS to the ENVIRONMENTAL RESOURCES ELEMENT Draft: Prepared November 2013
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SUPPLEMENTAL MATERIALS TO THE ENVIRONMENTAL RESOURCES ELEMENT Draft: Prepared November 2013 TABLE OF CONTENTS OVERVIEW 1 SECTION I. WILDLIFE RESOURCES 6 WILDLIFE SPECIES OF SPECIAL CONCERN 6 CRITICAL WILDLIFE HABITAT 9 PREBLE’S MEADOW JUMPING MOUSE HABITAT CONSERVATION AREAS 13 SECTION II. VEGETATION RESOURCES 16 PLANT SPECIES AND COMMUNITIES OF SPECIAL CONCERN 17 RARE PLANT AREAS AND SIGNIFICANT NATURAL COMMUNITIES 21 WETLANDS AND RIPARIAN AREAS 24 SECTION III. LANDSCAPE-SCALE DESIGNATIONS 29 ENVIRONMENTAL CONSERVATION AREAS 29 HIGH BIODIVERSITY AREAS 33 NATURAL AREAS 34 NATURAL LANDMARKS 36 LITERATURE CITED 37 APPENDICES A: GLOSSARY 38 B: CHRONOLOGY OF ENVIRONMENTAL RESOURCE UPDATES 43 C: SUBJECT MATTER EXPERTS 45 D: ADDITIONAL SOURCES FOR WILDLIFE RESOURCES SECTION 48 E: ADDITIONAL SOURCES FOR VEGETATION RESOURCES SECTION 51 F: A BRIEF HISTORY OF RARE PLANTS AREAS AND SIGNIFICANT 57 NATURAL COMMUNITIES DESIGNATIONS G: A BRIEF HISTORY OF WETLAND AND RIPARIAN AREA DESIGNATIONS 60 H. CRITICAL WILDLIFE AREA DESCRIPTIONS 62 I. ENVIRONMENTAL CONSERVATION AREA DESCRIPTIONS Environmental Resources Element Page 1 Draft, 11/12/2013 Supplemental Materials SUPPLEMENTAL MATERIAL ENVIRONMENTAL RESOURCES ELEMENT 2013 UPDATE OVERVIEW Purpose of the Supplemental Materials The Environmental Resources Element (ERE) has been a cornerstone of the county’s land use decision‐ making process since the Boulder County Comprehensive Plan (BCCP) was first adopted in 1978. The ERE has served well as a core element of the county’s land use vision, resulting in the quality of life we enjoy today. As is true with this update, the maps of the ERE playing a particularly important role illustrating what is unique and distinctive about the county: the species, habitats, and ecosystems that are particularly at risk of being lost from the county. The year‐long, multi‐faceted update process that has produced this invaluable inventory and assessment has provided updated maps and lists of important environmental resources that will serve the county for many years to come. It is important to keep in mind that the resources highlighted by the maps and lists of species of special concern may not be comprehensive. However, they do provide a frame of reference for understanding and analyzing potential trade‐offs in any decision‐making process. In addition to the maps, criteria, and lists that staff has prepared for inclusion in the ERE, this volume of supplemental materials is intended to provide more detailed information that supports the information displayed on the updated maps and could serve as a reference for future decision‐making. These supplemental materials are a very important component of the update in and of themselves. On the one hand, they provide the background material to Planning Commission, POSAC, BOCC, and the public that demonstrates the methodical, scientific approach behind the proposed updates. And, like previous versions of the ERE, this material also serves as a point of reference or snap shot of the state of Boulder County’s environmental resources at this moment in time. In addition, these supplemental materials provide a more detailed inventory of the characteristics of each of these environmental resources. This information can be used to assess future land use proposals and in county lands management, as well as informing the county’s advocacy and partnership activities with other jurisdictions, quasi‐public entities, and non‐governmental organizations. This information includes: Context for the scientific principles and process utilized in the update A synthesis of historical information from previous iterations of the ERE and the BCCP Descriptions of the criteria and methods used to develop the Lists of Species of Special Concern and to identify the areas designated on each of the maps Specific descriptive information about individually designated areas such as Critical Wildlife Habitats and Environmental Conservation Areas Environmental Resources Element Page 1 Draft, 11/12/2013 Supplemental Materials Boulder County’s Unique Ecological Diversity Extending from the Great Plains in the east, westward to the crest of the Continental Divide, Boulder County is home to a unique combination of prairie, forest and tundra environments. The rolling plains that cover the eastern third of the County at lower elevations (4,896 – 5,498 ft.) abruptly give way to tree‐covered slopes which reach up to treeline near 11,500 ft. The western border of the County is composed primarily of tundra and is formed by the Continental Divide where the mountain range towers above 12,000 ft. Within the borders of the county, the Divide reaches its most eastern point of any place on the continent. Long's Peak, which is located in Rocky Mountain National Park, is the highest point in the County (14,259 ft.). Southern Rocky Central Shortgrass Mountains Prairie Figure 1: Map of the major life zones of Boulder County. The major life zones include: Plains, Lower Montane, Upper Montane, Subalpine, and Alpine, and the ecotones occurring between them. The East-West change in life zones occurs along a steep elevational gradient. These lifezones were modeled after the environmental gradient of vegetation described for the northern Front Range by Kaufmann et al. 2006 Environmental Resources Element Page 2 Draft, 11/12/2013 Supplemental Materials Boulder County sits at the interface of two distinct ecoregions: the Southern Rocky Mountains and Central Shortgrass Prairie. The environmental uniqueness of the county is largely influenced by abrupt altitudinal variation that occurs within a relatively short 20 mile east‐west gradient. These dramatic changes in landform sharply define the local native ecosystems and their associations of plant and animal species. The County is comprised of five major lifezones which occur in longitudinal bands following the east‐west elevation gradient: Plains, Lower Montane, Upper Montane, Subalpine, and Alpine zones (Figure 1). While some species of flora and fauna can be found in many or all of these lifzones, many species are highly specialized and are restricted to one or a few habitat types within a single lifezone. Some migratory species utilize a large portion of each life zone during their lifetimes. Boulder County's ecological diversity is unique not only for the Rocky Mountain region, but also for the nation as a whole. Boulder County has long been recognized as a place of great natural beauty and diversity. Since the late 1800s when miners first settled in the valley, many people have been drawn to the Boulder area to enjoy the quality of life found along the Front Range of Colorado. During the 1990s, the Front Range experienced a population explosion, with a population increase of 29.3% from 1990 to 2000 (U.S. Census Bureau 2008). In Boulder County, for example, population increased in the towns of Superior and Erie by 4,795% and 1,342%, respectively, over the twenty years between1990 and 2010 (Colorado Conservation Trust 2012). Substantial development and recreational pressure followed this dramatic increase in population. The demands on our natural resources to support this increasing population have resulted in an increased threat of potential degradation of the quality and uniqueness of our county’s environmental resources. The increased utilization and fragmentation of our natural environment has altered important ecological processes that support human health and overall ecological health, also increasing the loss of native species and their unique habitats. Despite these increasing demands on local environmental resources, much of our native ecosystems retain some or lal of their natural integrity, especially when compared to many other places in our nation. This is due in large part to the foresight of the leaders and citizens of Boulder County in implementing land use planning tools like the BCCP beginning in the 1960s and 70s that emphasize the prudent consideration of natural resources. The decisions we make today about how to continue to support our commitment to land use and conservation practices that sustain native ecosystems will determine the degree to which the county’s great natural beauty and biological diversity are preserved and the goals of the Environmental Resources Element are sustained. Overview of the ERE’s Designated Environmental Resources Boulder County values and strives to preserve, conserve and restore the unique and distinctive natural features, ecosystems and landscapes of the county using sound resource management principles and practices at both a site‐specific level and on a broader, landscape scale. Boulder County's important environmental resources include naturally occurring ecosystems and their native species populations. The designations described in detail in these Supplemental Materials provide an inventory and illustration of the unique and distinctive environmental resources in the county and discuss approaches to best managing and conserving these resources. Species of Special Concern are an integral component Environmental Resources Element Page 3 Draft, 11/12/2013 Supplemental Materials of this management approach. The list of Species of Special Concern includes locally threatened or endangered wildlife, plants and plant communities that the county seeks to protect. Habitat for these Species of Special Concern is particularly vital, since it often presents our best chance to protect native species. In addition to identifying Species of Special Concern, the ERE designates areas