Detailed habitat assessments were conducted by CBI, TNC, and SDSU within the four designated South County grassland management planning units: Sweetwater Reservoir, Proctor Valley, Rancho Jamul Ecological Reserve, and Sycamore Canyon (Figure 1). All four units were assessed in 2011; additional assessments were conducted in 2012 at Rancho Jamul Ecological Reserve and Sycamore Canyon. The purpose of these assessments was to document existing habitat conditions and determine habitat suitability for the three target species (burrowing owl, Otay tarplant, and Quino checkerspot butterfly), as well as threats, results of past management actions, and potential management and restoration actions. Data from the habitat assessments were used to identify and prioritize species-specific management actions within each of the four planning areas. In addition, these data were used to identify preliminary vegetation associations, as well as potential restoration sites for native grasslands and forblands. Prior to conducting fieldwork, CBI and TNC reviewed soil maps, aerial photographs, and results of previous vegetation mapping, and plant and wildlife surveys in the project areas and vicinity.
This Land Management Plan (LMP) was prepared to guide the California Department of Fish and Game (herein referred to as the Department) in the management, maintenance and restoration of the biological diversity and ecosystem components currently and historically present within the Rancho Jamul Ecological Reserve (RJER). RJER is located in southwestern San Diego County between the communities of Jamul and Dulzura, approximately 26 miles east-southeast from downtown San Diego (Figure 1). It is nestled between the Jamul Mountains to the west, Otay Mountains to the south, and Cleveland National Forest to the northeast (Figure 2). The irregularly-shaped area covered by this LMP occupies 4,701.5 acres, which does not include two non-contiguous areas (2 of 3 Proctor Valley Unit pieces) to the west. This will be explained in more detail in Section B. Acquisition History. RJER borders on State Route (SR) 94 for approximately four miles along the northeastern edge of the property (Figure 3). Otay Lakes Road runs east to west just north of the southern border of the property.
Rancho Jamul Ecological Reserve, a 3,700-acre property previously operated as a
cattle ranch, became part of the California Department of Fish and Game reserve system in
1998. Following this acquisition, the U.S. Geological Survey conducted surveys to establish
baseline species data and vegetation data layers. Through cooperation with San Diego State
University, a vegetation and land cover GIS layer was developed which details the extent and
types of vegetation classes found on the reserve. This vegetation mapping established that 15
native and non-native vegetation types, the majority of which had disturbed counterparts,
occurred throughout the reserve. Rare plant surveys conducted by McMillan Biological
Consulting provided documentation of 131 native and non-native plant species, 18 of which
are considered sensitive species. Of these, five plant species detected on the reserve are
covered under the Multiple Species Conservation Program. Aquatic surveys reported four
native and two non-native amphibian species and six non-native fish species. Herpetofauna
pitfall arrays detected four native amphibian species, ten lizard species, and twelve snake
species. Twenty-one ant species were recorded using ant pitfall traps co-located at the
herpetofauna pitfall arrays. Bird point counts and incidental bird sightings recorded 94 bird
species present on or near the study site. Twelve bat species were detected using mist
netting, acoustic surveys, and roost site visits. Sherman live traps, combined with
herpetofauna pitfall arrays small mammals captures, documented 14 small mammal species
present on the reserve. Remotely triggered cameras and track stations were used to
document the presence of 11 medium and large bodied mammal species. A total of 150
native vertebrate species and nine non-native vertebrate species were recorded during these
surveys. Two herpetofauna species, eight bird species, and two mammal species detected on
the reserve are covered under the Multiple Species Conservation Program. Incidental records
of the Quino checkerspot butterfly were made onsite during the rare plant surveys, adding
this reserve to its known distribution. Summary statistics, discussion, and management
recommendations on the flora and fauna of the Rancho Jamul Ecological Reserve are
provided in this report.
Hollenbeck Canyon Wildlife Area (HCWA), a 3,200-acre property historically used as cultivated agriculture and grazing lands, became part of the California Department of Fish and Game (CDFG) reserve system in 2001. Following this acquisition, the U. S. Geological Survey conducted surveys to establish baseline species data. Herpetofauna pitfall arrays and incidental sightings detected 2 amphibian species, 10 lizard species, and eight snake species. Twenty-eight ant species were recorded using ant pitfall traps co-located at the herpetofauna pitfall arrays. Bird point counts and incidental bird sightings recorded 104 bird species present at Hollenbeck Canyon Wildlife Area and the neighboring Rancho Jamul Ecological Reserve (RJER). Sherman live traps, combined with herpetofauna pitfall arrays small mammals captures, documented 14 small mammal species present at Hollenbeck Canyon Wildlife Area. Thus a total of 134 native vertebrate species, 28 native invertebrate species (ants) and four non-native vertebrate species were recorded during these surveys. Of these, one avifauna species is listed as a California Department of Fish and Game endangered species, two herpetofauna species, 14 avifauna species and three small mammal species are listed as California Department of Fish and Game Species of Special Concern, and two herpetofauna species and seven avifauna species are covered under the San Diego Multiple Species Conservation Program.
The proposed project is the approval and implementation of an initial Rancho Jamul EcologicalReserve (RJER) Land Management Plan (LMP). The reserve provides numerous public use opportunities as well, including recreation, managed hunting, scientific study, and education. This reports details the maintenance activities that will be conducted within RJER.
We investigated the role of large-scale wildfires on the community composition and
structure of foraging bats within San Diego County, California. In October and
November of 2003, large–scale wildfires burned nearly 130,000 hectares of San Diego
County. To assess the potential impacts of these fires on the native bat communities, we
conducted surveys at eleven sites within each of our two study areas, Rancho Jamul
Ecological Reserve - Hollenbeck Canyon Wildlife Area and Santa Ysabel Open Space
Preserve. At each study area a subset of these sites was sampled before the fires (2001-
2003) and a subset after the fires (2005-2006). Our pre-fire sampling efforts included
five survey techniques: active-Anabat, mist-netting, roost, visual, and audible. These
same five techniques were employed during the first year of post-fire sampling, 2005. In
2006, we altered our survey methods by discontinuing mist-netting and began using
passive-Anabat monitoring stations instead of an actively monitored station.
We investigated the role of large-scale wildfires on the relative abundance of carnivores at
two study areas within San Diego County of southern California, 1) Santa Ysabel Open Space
Preserve and 2) Rancho Jamul Ecological Reserve-Hollenbeck Canyon Wildlife Area. In October
and November of 2003, large-scale fires burned approximately 130,000 ha of San Diego County. To
assess fire impacts on local carnivore communities, we collected data using two sampling
techniques, 1) track surveys with baited scent stations and 2) remotely triggered camera stations.
Sampling prior to the fires was conducted between May 2001 and June 2003, while post-burn
sampling was conducted between August 2006 and September 2007. We calculated the relative
abundance of carnivore species for each track transect and camera station, comparing pre-burn and
post-burn abundance indices.
Fifteen medium to large mammal species were detected across Santa Ysabel and Rancho
Jamul at track transects and camera stations. We detected 11 native species including mountain lion
(Puma concolor), mule deer (Odocoileus hemionus), coyote (Canis latrans), bobcat (Felis rufus),
badger (Taxidea taxus), gray fox (Urocyon cinereoargenteus), raccoon (Procyon lotor), striped
skunk (Mephitis mephitis), spotted skunk (Spilogale gracilis), opossum (Didelphis virginiana), and
long-tailed weasel (Mustela frenata). We also detected four species typically associated with humans
including, domestic cow (Bos taurus), domestic horse (Equus caballus), domestic dog (Canis
familiaris), and domestic cat (Felis catus). Ten of the native species (badger excluded) and two
human-associated species (domestic horse and domestic dog) were documented within both study
sites.
Within Santa Ysabel and Rancho Jamul, we found little evidence that the 2003 wildfires
affected the relative abundance of the carnivore species for which we gathered sufficient data. Most
of the species we studied seemed capable of persisting in the patchwork of unburned and burned
habitats resulting from these wildfires. In addition, the effects of the fires were likely short term for
most carnivore species. We did not begin post-burn monitoring until nearly three years after the
wildfires of 2003, by which time we likely missed the more dramatic immediate responses to
wildfire. Overall, we suspect the indirect effects of wildfires, such as changes in habitat suitability
and predator-prey dynamics, were largely responsible for the mi
This review prioritizes infrastructure improvements of 35 existing undercrossings inspected by wildlife experts in the field along 14.6 miles of SR-94 where the highway bisects conserved lands—particularly between the San Diego National Wildlife Refuge (SDNWR), where a box culvert has been designed specifically for this undercrossing, between Rancho Jamul Ecological Reserve (RJER) and Hollenbeck Canyon Wildlife Area (HCWA), and between Bureau of Land Management (BLM) lands and the Lawrence and Barbara Daley Preserve (LB Daley). In total, SR-94 crosses >10 miles of conserved lands with only three bridges—at the Sweetwater River, Dulzura Creek, and Campus Grove bridge in Dulzura. Following is a summary of improvements recommended for existing undercrossings and proposed new undercrossings, by segment, presented in this document.
We investigated the role of large-scale wildfires on the relative abundance of carnivores at two study areas within San Diego County of southern California, 1) Santa Ysabel Open Space Preserve and 2) Rancho Jamul Ecological Reserve-Hollenbeck Canyon Wildlife Area. In October and November of 2003, large-scale fires burned approximately 130,000 ha of San Diego County. To assess fire impacts on local carnivore communities, we collected data using two sampling techniques, 1) track surveys with baited scent stations and 2) remotely triggered camera stations. Sampling prior to the fires was conducted between May 2001 and June 2003, while post-burn sampling was conducted between August 2006 and September 2007. We calculated the relative abundance of carnivore species for each track transect and camera station, comparing pre-burn and post-burn abundance indices.
Fifteen medium to large mammal species were detected across Santa Ysabel and Rancho Jamul at track transects and camera stations. We detected 11 native species including mountain lion (Puma concolor), mule deer (Odocoileus hemionus), coyote (Canis latrans), bobcat (Felis rufus), badger (Taxidea taxus), gray fox (Urocyon cinereoargenteus), raccoon (Procyon lotor), striped skunk (Mephitis mephitis), spotted skunk (Spilogale gracilis), opossum (Didelphis virginiana), and
long-tailed weasel (Mustela frenata). We also detected four species typically associated with humans including, domestic cow (Bos taurus), domestic horse (Equus caballus), domestic dog (Canis familiaris), and domestic cat (Felis catus). Ten of the native species (badger excluded) and two human-associated species (domestic horse and domestic dog) were documented within both study sites. Within Santa Ysabel and Rancho Jamul, we found little evidence that the 2003 wildfires affected the relative abundance of the carnivore species for which we gathered sufficient data. Most of the species we studied seemed capable of persisting in the patchwork of unburned and burned
habitats resulting from these wildfires. In addition, the effects of the fires were likely short term for most carnivore species. We did not begin post-burn monitoring until nearly three years after the wildfires of 2003, by which time we likely missed the more dramatic immediate responses to wildfire. Overall, we suspect the indirect effects of wildfires, such as changes in habitat suitability and predator-prey dynamics, were largely responsible for the minor changes we observed
The Conservation Biology Institute (CBI), The Nature Conservancy (TNC), LandIQ, and
the California Department of Fish and Wildlife (DFW) conducted a 3-year experiment on
Rancho Jamul Ecological Reserve (RJER) to assess different control methods for
enhancing Otay tarplant (Deinandra conjugens) in recently burned habitat.
The Otay tarplant Habitat Experimental Project (project) goals included: (1) determine
whether an Otay tarplant soil seed bank exists onsite, (2) assess the response of Otay
tarplant to prescribed fire and nonnative plant control methods and (3) enhance Otay
tarplant habitat by controlling nonnative seed production and inputs to the soil seed bank.
The County of San Diego owns or is in the process of acquiring key lands within the Multiple Species Conservation Program (MSCP) preserve area. The MSCP Biological Monitoring Plan requires monitoring of covered plant species. The County of San Diego was awarded two Natural Communities Conservation Planning (NCCP) Program Local Assistance Grants to accomplish the first phase of the monitoring program, i.e., collecting baseline data for covered plant species. The study area of this grant was amended to include lands in San Vicente (Boys and Girl?s Club) Ecological Reserve that were originally included in the statement of work for the NCCP Local Assistance grant No. P0050008. The lands in the total amended study area, from north to south are open space areas in Santa Fe Valley, County-owned portions of Lusardi Creek, open space areas conveyed to the County of San Diego in 4S Ranch, San Vicente Open Space Preserve, McGinty Mountain preserve lands, Hollenbeck Canyon Wildlife Area, and lands north and south of the eastern arm of Otay Lakes. Portions of Rancho Jamul Ecological Reserve were also surveyed.
To investigate the role of large-scale wildfires on the scorpion and solifugid species
within San Diego County of southern California, we examined specimens that had been collected
from four study sites distributed across the region from both before and after the 2003 wildfires:
1) Santa Ysabel Preserve, 2) Rancho Jamul Ecological Reserve-Hollenbeck Canyon Wildlife
Area, 3) Little Cedar Ridge, and 4) Elliott Chaparral Reserve. In October and November of
2003, large-scale fires burned approximately 130,000 ha of San Diego County. We collected
data to assess fire impacts on the local solifugid and scorpion communities using drift fence
arrays with pitfall traps. Sampling prior to the fires was conducted between May 1998 and June
2003. Post-fire sampling was conducted between January 2005 and September 2007 with the
objective of identifying impacts of wildfire on the scorpion and solifugid communities. We
calculated monthly detection frequencies of each species to test for differences in seasonal
activity patterns between scorpions and solifugids. We compared total species richness, rates of
species accumulation, and average species richness detected per sample occasion between preand post-fire sample periods to describe major differences in the pre- and post-fire datasets. To
test for the effects of wildfire on the community, we compared pre- to post-fire differences in the
average species richness per sample occasion between burned and unburned plots, as well as
modeled the effects of vegetation, plot condition (burned or unburned), and their interaction on
the species richness measures for post-fire periods. We also tested for associations between
vegetation types and individual scorpion and solifugid species and for the two most dominant
species, constructed site occupancy models to compare occupancy among sites, vegetation types,
and between burned and unburned plots.
