City of Monrovia Chapter 4 Community Wildfire Protection Plan Vegetation November 2014 Fire Ecology and Management of Vegetation Types Fire Ecology and Management of Monrovia Foothills Vegetation Types ................................................................ 2 4.1. Vegetation Communities of the Monrovia Foothills ............................................................................... 2 4.1.1. Rare and Protected Plants and Wildlife of the Monrovia Foothills ................................................ 5 4.2. Chaparral and other Scrub-Type Vegetation ........................................................................................... 9 4.2.1. Chaparral Plant Adaptations to Fire ............................................................................................. 10 4.2.2. Chaparral Fire Regime ................................................................................................................. 11 4.2.3. Chaparral Conservation and Fuel Modification Objectives .......................................................... 13 4.2.4. Chaparral Fuel Modification Treatment Prescription ................................................................... 15 4.3. Oak Woodland ...................................................................................................................................... 18 4.3.1. Oak Woodland Role of Fire ......................................................................................................... 18 4.3.2. Oak Woodland Fire Regime......................................................................................................... 19 4.3.3. Oak Woodland Plant Adaptations to Fire ..................................................................................... 19 4.3.4. Oak Woodland Conservation and Fuel Modification Objectives ................................................. 19 4.3.5. Oak Woodland Fuel Modification Treatment Prescription........................................................... 20 4.4. Riparian ................................................................................................................................................ 22 4.4.1. Riparian Role of Fire ................................................................................................................... 23 4.4.2. Riparian Fire Regime ................................................................................................................... 23 4.4.3. Riparian Plant Adaptations to Fire ............................................................................................... 24 4.4.4. Riparian Conservation and Fuel Modification Objectives ............................................................ 24 4.4.5. Riparian Vegetation Fuel Modification Treatment Prescription ................................................... 24 4.5. Grassland .............................................................................................................................................. 26 4.5.1. Grassland Role of Fire ................................................................................................................. 27 4.5.2. Grassland Fire Regime ................................................................................................................. 27 4.5.3. Grassland Plant Adaptations to Fire ............................................................................................. 27 4.5.4. Grassland Conservation and Fuel Modification Objectives ......................................................... 27 4.5.5. Grassland Fuel Modification Treatment Prescription ................................................................... 28 4.6. Landscape-Level Fuel Management in Monrovia’s Wildland Interface ............................................... 29 4.7. Monrovia Foothills Best Management Practices .................................................................................. 30 4.7.1. Tree Planting and Care ................................................................................................................. 33 4.8. Seasonal Guide to Fire Preparedness .................................................................................................... 36 4.9. Plant Lists.................................................................................................................................. 37 Page 4-1 City of Monrovia Chapter 4 Community Wildfire Protection Plan Vegetation November 2014 Fire Ecology and Management of Monrovia Foothills Vegetation Types1 4.1. Vegetation Communities of the Monrovia Foothills The distribution of different types of vegetation within the fire hazard portion of Project Area is shown in Figure 4-1. The mapped units are what ecologists call vegetation communities2 and they are identified in Table 4-2, and further described in the subsections below. The map is founded on vegetation maps of the Hillside Wilderness Preserve (HWP), which were created previously for the environmental documentation during 2006 and 2010. As the CWPP project area covers an additional area of about 1,000 acres that are outside of the HWP, the previously mapped area has been extended to the WUI border by means of extrapolating from the mapped vegetation zones using aerial photograph review. Figure 4-1 presents the resulting vegetation map. Figure 4-1: Monrovia CWPP Fire Zone Vegetation Map 1 This section is adapted from a publication by Marko Bey, Lomakatsi Ecological Services, and Susan Britting, Ph.D., and a report ,“Vegetation Ecology and Management in the Monrovia Foothills: Best Management Practices for Living with Wildfire”, April 22, 2011, by Daniel S. Cooper, Cooper Ecological Monitoring, Inc., 5850 W. 3rd St., #167, Los Angeles, CA 90036, prepared for the City of Monrovia. The original Cooper report is provided in Appendix A-1 of this CWPP. 2 Vegetation Community: A group of plants that are interrelated and occupy a given area. Page 4-2 City of Monrovia Chapter 4 Community Wildfire Protection Plan Vegetation November 2014 Table 4-1 Monrovia CWPP Fire Zone Vegetation Summary Conservation Vegetation Type Vegetation Community Status Acres Chaparral 812.2 Southern Mixed Chaparral (CH) 812.2 Scrub 211.4 Alluvial Fan Scrub (ALL) Rare3 10.2 Coastal Sage Scrub (CSS) Rare 14.3 Coastal Sage Scrub/Chaparral Ecotone (CSS/CH) 186.9 Oak Woodlands 664.6 Southern Coast Live Oak Woodland (O) Rare 462.2 Oak/Chaparral Ecotone (O/CH) 132.2 Mixed Oak/Ornamental Landscaping (O/ORN) 12.9 Oak/Sycamore Woodland (O/S) 55.6 Oak/Sambucus(Elderberry) Ecotone O/SAM 1.8 Riparian 28.0 Alder Riparian Forest (ALD) 19.2 Sycamore Riparian Woodland (S) Rare 2.1 Sycamore/Alder Riparian Woodland (S/ALD) 5.3 Water (W) 0.4 Willows (WIL) 1.0 Grasslands 2.7 Grassland (G) 2.7 Developed and/or Disturbed 715.8 Developed Areas (DEV) 613.0 Disturbed (DIS) 33.0 Disturbed/Ornamental Landscaping Mix (DIS/ORN) 58.8 Pine Species (P) 5.4 Rural Residential (R) 5.6 Grand Total 2434.8 In Figure 4-1 and Table 4-1 we present the vegetation distribution within only that portion of the CWPP project area that is within the Very High Fire Hazard Severity Zone (VHFHSZ). We do not include the vegetation within the Ember Protection Zone (EPZ) because that area is removed from the wildland vegetation, or of the Safety Zone (SZ) because that area is even more urbanized. However, we need to recognize that this is a simplification of conditions: significant areas of almost-wild vegetation may exist within urbanized areas, and vice versa. Following are brief descriptions of these vegetation types. (Each is discussed in greater detail in the subsequent sections devoted to their fire ecology and management.) 3 Reference/explanation needed. Page 4-3 City of Monrovia Chapter 4 Community Wildfire Protection Plan Vegetation November 2014 Chaparral Chaparral vegetation (CH) consists of evergreen, dark‐green leaved, medium‐height to tall shrubs that are adapted to occasional wildfires. Plant species commonly found in the chaparral in Monrovia include laurel sumac (Malosma laurina), chamise (Adenostoma fasciculatum), toyon (Heteromeles arbutifolia), and redberry (Rhamnus crocea). As the community matures, it becomes woody and produces high fuel loads. Chaparral is found on steep slopes of all aspects in the Project Area. In some areas, the coastal sage scrub elements exist in patchy association with chaparral. Scrub oak (Quercus berberidifolia) also occurs sporadically throughout this community. Also noteworthy is a stand of arborescent goldenbush (Ericameria arborescence) that is found in a historically excavated bowlshaped area located north of Highland Place. This species appears to be only sporadically found throughout the surrounding hillside areas. Scrub Scrub also describes a principally shrub vegetation types, often nicknamed “soft chaparral”. Plant species commonly found in the scrub in Monrovia include California sagebrush (Artemisia californica), California buckwheat (Eriogonum fasciculatum), white sage (Salvia apiana), black sage (Salvia mellifera), and deer weed (Lotus scoparius). Urbanization and agricultural land conversion have resulted in a dramatic loss of scrub habitat in southern California, which makes this remaining habitat in Monrovia especially important. Coastal sage scrub (CSS) communities are scattered throughout the site in relatively small patches on ridge tops and hillsides. These communities are interspersed with the more common chaparral habitat – this vegetation is known as an “ecotone” – an area in which different