South Laguna Biological Resources Inventory
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SOUTH LAGUMA BIOLOGICAL RESOURCES INVENTORY Prepared for the City of Laguna Beach By Karl in G. Marsh, Biological Consul tant January 20, 1992 Karlin C. Marsh Biological Consultant 30262 Acorn Lane, P.O. Box 404, Silverado, California 92676 714/649-202 7 SOUTH LAGUNA BIOLOGICAL RESOURCES INVENTORY Prepared for the City of Laguna Beach By Karlin 6. Marsh, Biological Consultant Uith Contributions by Fred Roberts, Jr. r Dave Bramlet r Gordon Marsh Rick Reifner January 20, 1992 Dedicated With Affection and Admiration to FREDERICK M. LAN6 Longtime champion of South Laguna's special natural resources TABLE OF CONTENTS Page INTRODUCTION 1 BOUNDARIES AND PHYSICAL SETTING 1 SURROUNDING AND ONSITE LAND USES; OWNERSHIP 3 METHODS 5 EXISTING LITERATURE 6 BIOTIC COMMUNITIES 8 MARITIME SUCCULENT SCRUB (2.2) COASTAL SAGE SCRUB (2.3) SUMAC-TOYON SOUTHERN MIXED CHAPARRAL (3.2) SOUTHERN MARITIME CHAPARRAL (3.6) ANNUAL GRASSLAND (4.1) SOUTHERN COASTAL NEEDLEGRASS GRASSLAND (4.3) RUDERAL (4.6) I SOUTHERN HARDPAN VERNAL POOL (5.1) FRESHWATER SEEP (5.3) I ALKALI MEADOW (5.2) SOUTHERN COASTAL SALT MARSH (6.1) I COASTAL BRACKISH MARSH (6.2) I COASTAL FRESHWATER MARSH (6.4) RIPARIAN HERB (7.1) I SOUTHERN WILLOW SCRUB (7.2) MULEFAT SCRUB (7.3) SOUTHERN ARROYO WILLOW FOREST (7.6) COAST LIVE OAK WOODLAND (8.1) I XERIC CLIFF FACES (10.1) I XERIC BARRENS (10.1) Page MARINE TERRACE PSAMMOPHYTE HABITAT (10.1) MESIC CLIFF FACES (10.2) ROCK OUTCROPS (10.3) PERENNIAL STREAM (13.1) INTERMITTENT STREAM (13.2) EPHEMERAL STREAM (13.3) VINEYARD AND ORCHARD (14.3) ORNAMENTAL PLANTINGS (15.5) FUEL MODIFICATION ZONES (no G.I.S. #) 3.0 UESCRIPTION OF SOUTH LA6UNAaS OPEN SPACE AREAS 3.1 HOBO CANYON 3.1.1 Overview 1. Significance 2. Biotic Communities 3. Wildlife Values 4. Rare Plant Populations Censused A. Orange County Limited Distribution Taxa B. CNPS Limited Distribution (List 4) Species C. CNPS Rare and Endangered (List 1, 2) Species. D. State of California Threatened-Listed. 3.1.2 Habitat Description 43 1. The Highland Ridges A. West Ridge of Hobo Canyon B. Pleistocene Marine Terrace C. Hill 1 D. Hill 2 E. Hill 3 F. Saddle G. Hill 4 North of Ridge 4A H. Lateral Ridge 4A and Adjoining North-facing Slope I. Hill 4 South of Ridge 4A 3. Hill 5 2. Hobo Canyon Slopes and Floor A. East Slope B. West Slope C. Canyon Bottom D. Short Canyon South of Hobo Canyon Page 3.2 ALISO CANYON 5 7 3.2.1 Overview 5 7 3.2.2 Rare Plants and Animals 62 1. Flora A. Orange County Limited Distribution Taxa B. CNPS Limited Distribution List 4 Species C. CNPS Rare and Endangered in California List 2 Species D. CNPS Rare and Endangered Taxa E. California Threatened-listed Species 2. Fauna 3.2.3 Habitat Descri~tion 1. Aliso Canyon's South-facing Slope A. East Boundary Trail B. Trai 1 to Turnaround Loop C. Aliso-Hobo Ridge Slope Between Second and Third Trail D. Trail to Utility Pole 2. Aliso Canyon Floor and Lower Slopes A. AWMA Plant to Golf Course B. Lower South-Facing slope of Aliso Canyon C. Lower North-Facing Slope of Aliso Canyon D. Aliso Creek 3.3 ALISO PEAK AND CEANOTHUS CANYON 9 1 3.3.1 Overview; Rare Biota 9 1 3.3.2 Aliso Peak 93 1. Seaview Park 2. Trails West of Seaview Park 3. Aliso Peak Open Space A. Saddle B. Aliso Peak 4. Additional Species of Interest on Niguel Hill-Aliso Peak 3.3.3 Ceanothus Canyon 103 1. South-Facing Slope 2. Canyon Floor 3. North-Facing Slope 4. South Ridge iii Page 3.4 THE BADLANDS CANYONS 110 3.4.1 Overview 3.4.2 Rare Biota 3.4.3 Habitat Description 1. Canyon 1 2. Ridge Between Canyon 1 and 2 3. Canyon 2 4. Ridge Between Canyon 2, 3 and Headwater of 4, North Branch 5. Canyon 3 6. Ridge Between Canyon 3 and 4 7. Canyon 4 8. Ridge Between Canyon 4 and 5 9. Canyon 5 10. Canyon 6 11. Badlands Park 3.4.4 Wildl ife Clbserved in the Badlands Canyon Area 3.5 BINION PARCEL 3.5.1 Physical Setting 3.5.2 Methods 3.5.3 Proposed Land Use 3.5.4 Biological Setting 1. Ridge 2. Upper Slopes 3. Lower Slopes 3.5.5 Findings and Recommendations 4.0 RESOURCE SENSITIVITY ANALYSIS 4.1 OVERVIEW OF CRITERIA 4.2 SENSITIVE SPECIES 4.2.1 Plants 4.2.2 Animals 4.3 SENSITIVE HABITATS 4.4 CRITERIA FOR DETERMINING BIOLOGICAL VALLIE OF OPEN SPACES IN SOUTH LAGUNA Page 4.5 SUMMARY OF SOUTH LAGUNA'S SIGNIFICANT HABITATS 170 4.5.1 Very High Biological Value 170 1. Hobo Canyon; South-facing Slope of Aliso Canyon 2. Niguel Hill, Aliso Peak, North-facing Slope of Aliso Canyon Gorge, and Ceanothus Canyon 4.5.2 High Biological Value 170 1. Badlands Canyons and Badlands Park 2. Lower Aliso Creek 3. Binion Slopes 4.5.3 Moderate Bioloaical Value 171 Urban Forests 4.5.4 Low Biological Value 1. South Portion of Open Space 2. Golf Course 3. Fuel Modification Zones 5.0 RECOMMENDATIONS 5.1 OPEN SPACE ACQUISITION 5.1.1 Existing Conditions 5.1.2 Proposed Acquisitions 1. Hobo Canyon and Contiguous South-facing Slope of Aliso Canyon 2. North-facing Slope of Aliso Canyon 3. South Coast Water District Property 4. Other Suggested Open Space Acquisitions 5.2 RESOURCE MANAGMENT 5.2.1 Moulton Meadows 5.2.2 Aliso Creek 1. Regional Resource Management Plan 2. Onsite Rehabilitation A. Rehabilitation Within Golf Course B. Rehabilitation Downstream from Golf Course C. Other Recommendations for Lower Aliso Creek Page 5.2.3 Niauel Hill-Aliso Peak 184 1. Landscape Materials 2. Trails 5.2.4 Ceanothus Canyon South Ridge; Badlands Canyons 186 1. Fuel Modification Zone 2. Fowlie Structure Footprint 3. Erosion 5.2.5 Badlands Park 1. Irrigation 2. Landscape Materials 3. South Bowl 5.2.6 Binion Property 5.2.7 Regional Fuel Modification Zone 6.0 APPENDIX 1 6.1 SPECIES LISTS 6.1.1 Flora Species List 6.1.2 Fauna Species List 1 6.2 REFERENCES 6.2.1 Persons and Organizations Consulted 6.2.2 Bibliography 1.0 INTRODUCTION This report describes the biological resources of the South Laguna, California open space, excluding the seacoast. The open space consists of a total of approximately 771 acres, and includes the .following localities. 0 Hobo Canyon 0 Lower Aliso Canyon a Aliso Peak - Niguel Hill Ridge. Most of the latter is within the City of Laguna Niguel 0 Ceanothus Canyon a The South Laguna so-called Badlands Canyon Binion Parcel In addition is partially developed and heavily fuel-modified land south of the Binion Parcel to the Dana Point City limits. The purpose of preparing this inventory is to add a data base for South Laguna to that existing for the City of Laguna Beach prior to its annexation. The original Laguna Beach Biological Resources Inventory was prepared by the author, Fred Roberts, Jr. and John Lubina, with contributions by Gordon Marsh, in 1982-82, and submitted to the City on 1-31-83. It was followed by the Sycamore Hills Biological Resources Inventory, submitted 6-9-83 and a spring followup survey for the first study, sub- mitted 6-27-83. 1.1 BOUNDARIES AND PHYSICAL SETTING The South Laguna annexation area extends from Arch Beach Heights, north to Three Arch Bay in the City of Dana Point, south. The inland boundaries are Aliso and Wood Canyons Regional Park, north and the developed and undeveloped Niguel Hill ridge- line in the City of Laguna Niguel, south. The western boundary is the Pacific Ocean. South Laguna lies entirely within the City of Laguna Beach, which is located in coastal southern Orange County, California. The topography of the remaining open space in South Laguna is steep and rugged, which has been a factor slowing its urbaniza- tion. North of the Aliso Canyon Gorge, the high hill which separates this canyon from Hobo Canyon raises to 780 feet above sea level. Niguel Hill, on the south side of the Gorge is an astonishing 936 feet above sea level, and promontory Aliso Peak towers 6.23 feet above the seacoast below. The long uplifted terrace south of Niguel Hill, separating the short coastal can- yons from Arroyo Salada in the interior averages around 800 feet above sea level. Slopes and canyon dropping away oceanward from these backbone ridges and hilltops are quite precipitous. In the Aliso Canyon Gorge and in some of the smaller canyons, there are cliffs exposed which are essentially vertical. The Gorge, in particular is quite dramatic in its topography, especially when viewed from up the coast. Several important bedrock formations underlie the community's open space. These are Tertiary San Onofre breccia, Tertiary Topanga sandstone and Quaternary marine terrace. San Onofre breccia is composed of clasts of Catalina schist green schist and quartz in a cement-like matrix. According to Stadum, 1973, in the Tertiary Period, a peninsular range of mountains composed of this schist extended westward and south- ward from the present-day coast. The mountain range eventually eroded away; its debris accumulated along the south Orange County coast from the vicinity of Juanita Canyon in Laguna Beach to the Dana Point Headlands and inland some distance along Arroyo Salada (Crown Valley Parkway). The San Onofre breccia supports a regional ly rare plant community. Topanga sandstone is of about the same age as San Onofre breccia. This is a buff yellow marine deposited sandstone which characteristically erodes, creating scenic caves and grottoes.