Ecological Monitoring of the McConnell Foundation’s Ross Ranch

February 2017

Alicia D. Herrera

Ecological Monitoring of the McConnell Foundation’s Ross Ranch

February 2017

Alicia D. Herrera

Acknowledgements

This project was made possible by funding from the McConnell Foundation. I thank Point Blue Conservation Science staff Ryan DiGaudio, Wendell Gilgert, Breanna Owens, and Nathan Reese for their assistance in sample design and data collection. This report was greatly improved by feedback from Libby Porzig and Quinn White. Many thanks as well to the McConnell Foundation staff Alex Carter and Sarah Brady for their enthusiasm and collaboration on this project.

Suggested Citation

Herrera, A.D. 2016. Ecological Monitoring of the McConnell Foundation’s Ross Ranch. Point Blue Conservation Science, Petaluma, CA.

This is Point Blue Contribution No. 2117.

Point Blue Conservation Science

Point Blue’s 140 staff and seasonal scientists conserve birds, other wildlife, and their ecosystems through scientific research and outreach. At the core of our work is ecosystem science, studying birds and other indicators of nature’s health. Visit Point Blue on the web www.pointblue.org.

Cover photos: Point Blue’s Rangeland Monitoring Network measures soil dynamic properties, the vegetation community, and wildlife populations in order to evaluate the effectiveness of management practices. Photos by Alicia Herrera.

TABLE OF CONTENTS

EXECUTIVE SUMMARY ............................................................................................................ 1

INTRODUCTION ........................................................................................................................ 3

METHODS .................................................................................................................................... 4

Study Site ................................................................................................................................... 4

Sampling Design ...................................................................................................................... 4

Point Count Surveys ................................................................................................................ 5

Species Richness and Bird Abundance Calculations .......................................................... 5

Soil Surveys ............................................................................................................................... 6

Water Infiltration Test ......................................................................................................... 6

Bulk Density .......................................................................................................................... 7

Organic Carbon .................................................................................................................... 7

Soil Texture ........................................................................................................................... 7

Vegetation Surveys .................................................................................................................. 7

RESULTS ....................................................................................................................................... 8

Riparian Avian Point Count Species Richness and Abundance ....................................... 8

Rangeland Avian Point Count Species Richness and Abundance ................................. 10

Rangeland Soil Properties ..................................................................................................... 11

Vegetation Composition and Cover .................................................................................... 13

DISCUSSION .............................................................................................................................. 17

West Stillwater Creek Riparian ............................................................................................ 17

Rangeland ............................................................................................................................... 18

CONCLUSION ........................................................................................................................... 21

LITERATURE CITED ................................................................................................................ 22

APPENDICES ............................................................................................................................. 25

P a g e | 1

EXECUTIVE SUMMARY

In 2016 Point Blue Conservation Science collected baseline avian, soil, and vegetation data from Ross Ranch. To establish baseline ecological data for Ross Ranch, we measured avian species richness and abundance; soil water infiltration, organic carbon, bulk density, and texture; and vegetative composition and cover. Measurements were separated by riparian and rangeland habitat types and analysis of these baseline measurements shaped management recommendations to improve habitat health.

The scarcity of riparian focal bird species found along West Stillwater Creek is a strong indication that the habitat is not providing adequate food, shelter, or nesting locations to support the majority of breeding riparian species. The majority of vegetation that is present along riparian corridors is largely lacking the structural complexity one would expect to see in a healthy riparian habitat, and while there are some more robust sections of riparian vegetation, the habitat is fragmented and thus less attractive to wildlife.

The overall abundance and richness of birds within the Ross Ranch rangeland indicates a healthy and diverse breeding bird population and associated oak woodland. Samples indicate the property maintains a good litter layer and sufficient number of large-diameter trees, but few gray pine, standing snags, shrubs, or native bunchgrasses. Additionally, open grassland soil samples had relatively lower soil carbon, high bulk density, and slower water infiltration than those points sampled within the oak woodland.

While a large scale, creek-wide restoration effort would be ideal, connecting remnant riparian patches and widening the overall width of the riparian corridor would also help improve this habitat. Efforts to balance the vegetative complexity of the rangeland should be considered, and any activities or infrastructure that enable invasive species colonization (e.g., supplemental livestock feeding or watering facilities) should be implemented strategically and be located away from the oak woodland areas. Targeted compost applications, targeted seedings, prescribed grazing management, and promotion of nitrogen-fixing vegetation species could improve soil quality and fertility in grassland areas, increase carbon capture, improve overall plant growth, and increase native grass abundance at Ross Ranch.

P a g e | 2 Additional years of data collection are recommended in order to evaluate and help guide grazing practices, restoration efforts, and other management activities.

P a g e | 3

INTRODUCTION

Rangelands make up over 40% of the land area in California and include grasslands, deserts, oak savannas, riparian areas, and wetlands (Brown et al. 2004). This large extent and the value they provide to people makes rangelands economically, socially, and environmentally important. These lands support numerous and diverse plant and animal species and provide natural resources such as water and soil. Rangelands also provide livestock forage, recreation opportunity, open space, and natural beauty. They provide critical habitat to common, rare, and endangered species, and support a $3-billion cattle industry (USDA 2012).

However, urban development and conversion to intensive agricultural crops pose threats to California rangelands (Cameron et al. 2014, DeLonge et al. 2014). Between 1984 and 2008, an estimated 195,000 acres of rangeland in California were converted to other uses (Cameron et al. 2014). With this conversion, many of the ecosystem services these lands can support, including water capture and storage and wildlife habitat, have been degraded or lost. Climate change poses additional threats to rangeland ecosystem functions, such as extreme temperatures, flooding, drought, and changes in timing of wildlife life cycle events (phenology). Given their extensive geography, and the threats they face, there is an interest in better understanding the ecological values of rangelands and how grazing and other management practices can maintain, alter, or enhance their ecosystem function.

The McConnell Foundation’s Ross Ranch offers an exciting opportunity to demonstrate regenerative ranching and farming practices that can provide benefits to wildlife, recreational opportunities, and enhancement of rangeland ecological processes. Ecological monitoring is central to establishing a baseline in order to evaluate the effectiveness of management practices and impacts from public use. To establish baseline ecological data for Ross Ranch, we employed Point Blue’s Rangeland Monitoring Network’s multiple protocol system that includes measurements of soil dynamic properties (those we anticipate to change with shifts in management), the vegetation community, and wildlife populations (Porzig, et al. 2016).

Data was collected on soil bulk density, soil organic carbon, water infiltration, vegetation cover and composition, and avian species richness and abundance. In this report, we present baseline data collected in 2016.

P a g e | 4

METHODS

Study Site

All data were collected at The McConnell Foundation’s 812-acre Ross Ranch property in Shasta County, California. The property is primarily Blue Oak (Quercus douglasii) woodland with large areas of open savanna habitat, presumably where trees were historically removed. West Stillwater Creek flows through approximately 1.7 miles of the western side of the property in a southeasterly direction, and 0.5 miles of East Stillwater Creek forms part of the eastern boundary of the property. Approximately 13 miles of access roads and trails run through the property, some of which are being either decommissioned or improved in preparation of opening the property for public use.

Sampling Design

Sampling design followed that outlined in The Rangeland Monitoring Network: Handbook of Field Methods (Porzig et al. 2016). Rangeland point count locations were identified by overlaying a 250 meter (m) square grid on a map of the study area and using the Generalized Random Tesselation Stratified (GRTS) approach to select a spatially-balanced and random set of sampling locations, excluding those within 100 m of a property boundary and riparian areas (R Core Team 2016, Kincaid and Olsen 2015). In order to obtain a balanced representation of the rangeland, 16 monitoring points were included in the sampling effort. A separate transect along West Stillwater Creek consisting of 9 points spaced a minimum of 200 m apart was also monitored.

Soil and vegetation sampling sites were selected from a subset of the bird point count locations. Soil sampling sites represent the majority of ranch soil types, management practices, dominant vegetation types, and areas of special interest to the McConnell Foundation staff. (Table 1). See Appendix A for all monitoring locations.

Table 1. Monitoring dates by method and location at Ross Ranch in 2016.

Transect Point Count (1st Visit)

Point Count (2nd Visit)

Soil Sampling Vegetation Sampling

ROSS (rangeland) 4/28/2016 6/3/2016, 6/6/2016

2/24/2016, 3/24/2016

5/2/2016, 5/19/2016

STWA (riparian) 4/29/2016 6/2/2016 N/A N/A

P a g e | 5

Point Count Surveys

Standardized, five-minute exact-distance point count surveys were conducted at each point count station (Ralph et al. 1995). At rangeland points, we estimated the distance to each detected bird with the aid of rangefinders. At riparian points, detections were placed within one of six fixed-radius bins: 0-10, 10-20, 20-30, 30-50, 50-100, and greater-than-100 m based on the distance from the observer to the initial detection of that bird. All birds detected were recorded, along with an initial detection cue for each individual (song, visual, call, or wing noise). Surveys were conducted from local sunrise until approximately 3 hours after sunrise (i.e., peak singing hours), and not carried out in inclement weather. Locations were surveyed twice during the peak of the breeding season from late April to mid-June by qualified field biologists with extensive regional avian knowledge.

Species Richness and Bird Abundance Calculations

Analysis of point count data was restricted to a subset of the species encountered. We excluded: (1) species flying over the sampling locations but not actively using the habitat, (2) species that do not breed in the study areas, (3) those species that are not adequately sampled using the point count method (e.g. waterfowl, raptors, waders, swallows); and (4) Brown-headed Cowbird and exotic species (e.g. European Starling, Eurasian Collared Dove), except where noted. For the rangeland point counts, we excluded all birds more than 100 m from the observer, and for the riparian point counts along West Stillwater Creek, we excluded all bird more than 50 m from the observer. A list of all species detected at Ross Ranch, including scientific names, regardless of distance or exclusion from analyses is presented in Appendix B.

Some of our analyses are further restricted to California Partner’s in Flight focal species guilds—birds which represent a suite of specific habitat features and canopy layer associations, territory size requirements, and management regimes representative of a healthy system (CalPIF 2002). Monitoring focal species has been shown to be a useful approach to guiding management and conservation activities (Chase and Geupel 2005).

An oak woodland focal species guild was used for analysis of the rangeland point count data and included: Acorn Woodpecker, Ash-throated Flycatcher, Blue-gray

P a g e | 6 Gnatcatcher, California Quail, Hutton’s Vireo, Lark Sparrow, Nuttall’s Woodpecker, Oak Titmouse, Western Bluebird, Western Scrub-Jay, White-breasted Nuthatch, Yellow-billed Magpie, and European Starling. These focal species represent a diversity of ecological relationships with California’s oak woodlands, and include many species that consume acorns and several that cache acorns; insectivorous, scavenger, and granivorous specialists; primary and secondary cavity-nesting species; and endemic and long-distance migratory species. European Starling, a non-native species, was included as a major competitor for cavities in oak woodlands. A riparian focal species guild was used for analysis of the West Stillwater Creek point count data and included: Black-headed Grosbeak, Common Yellowthroat, Song Sparrow, Spotted Towhee, Tree Swallow, Yellow-breasted Chat, Yellow Warbler, and Brown-headed Cowbird. These focal species represent a diversity of ecological relationships with riparian ecosystems, and included resident and long-distance neo-tropical migrants; insectivores and granivorous specialists, cavity-nesting and open-cup nesting species; and early successional, mid-successional, and late-successional associated species, as well as Brown-headed Cowbird, a species that commonly parasitizes and depredates open-cup nests of riparian bird species. The indices of bird abundance herein are defined as the mean number of individuals detected per point, per visit, in one year. The indices of bird species richness herein are defined as the number of species detected per point across all visits in one year.

Soil Surveys

At each sampling location, five subsample sites were randomly identified within 50 m of the location center. At these subsample sites, water infiltration and bulk density were measured. Additionally, soil from the five subsample sites were pooled to generate a single measurement of soil carbon and soil texture for the location. Results across subsamples site were averaged to generate a single value of water infiltration and bulk density.

Water Infiltration Test

Water infiltration rates were sampled following the protocol in the NRCS Soil Quality Test Kit (1999). A 15.2 cm (6 inch) diameter PVC ring was inserted into the ground to 5 cm (2 inch) depth. The ring was lined with a plastic sheet as a barrier to the soil, and poured in 450 mL of water. The sheet was then removed and the time it took for the water to enter the soil was recorded. Following the initial trial, the plastic sheet was

P a g e | 7 reinserted and another 450mL of water was added. The sheet was then removed and infiltration time was recorded once again.

Bulk Density

Bulk density of the surface soil was measured by inserting a metal ring 5.2 cm (2 inches) in diameter and 7.5 cm (3 inches) tall in to the ground and removing the ring with soil contents. The contents were sealed in plastic bags and were weighed to the nearest 0.1 grams. In the lab, rocks were removed by sifting samples through a 2 mm mesh sieve. Rocks were weighed and volume determined by displacing water in graduated cylinder. Samples were then dried in an oven at 100° C for 24 hours. The samples were weighed again and the following calculation was used to estimate Bulk Density:

(g/cm³) = oven dry weight of soil / (volume of bulk density ring – volume of rocks)

Organic Carbon

Organic carbon was sampled to 40 cm depth using a step probe. The 0-10 cm depth was separated from the 10-40 cm depth. Five subsamples were taken around the center of each survey point and combined to produce one 0-10 cm sample and one 10-40 cm sample. Inorganic carbonates were removed with an acid pre-treatment, and organic carbon was measured by dry combustion using an Elemental Analyzer at the University of Idaho Soil Analytic Lab.

Soil Texture

Soil texture is an inherent property of soil; it is not sensitive to management. However, it is important to know the soil texture in order to interpret bulk density, infiltration, and soil carbon values accurately. Soil texture was classified via particle size analysis at the University of Idaho Soil Analytic Lab. The 10-40 cm layer, pooled across the 5 subsamples, was used to determine soil texture.

Vegetation Surveys

The vegetation monitoring protocol combined a line-point intercept (LPI) with visual estimate of woody species cover to quantify species-level information.

The line-point intercept closely followed the protocol outlined by Herrick et al. 2005. At each sampling location, two 50 m transects were selected by spinning a compass and pulling out a 50 m tape at the compass direction, as well as a second 50 m tape at 180°

P a g e | 8 from the first, to generate a single 100 m transect. Vegetation was sampled at 1 meter intervals along the transect. Observers stood on the same side of the tape and dropped a rod pointer from a low height, letting it fall freely to the ground and recording every plant species that intercepted the rod. The height at which the tallest plant species intercepted the rod was also recorded. Herbaceous and woody litter, if present, was recorded, and if no leaf, stem, or plant base intercepted the rod, “None” was recorded. Each plant species was recorded only once per rod drop, even if it intercepted the rod several times. Soil surface was record as either rock, soil, animal manure, embedded litter, moss, or visible biotic crust. Bare ground was defined as those points that had “None” in the top layer and no herbaceous or woody litter.

Following the line-point intercept survey, biologists walked a 50 m radius around the point center in a spiral or zig-zag for 20 minutes, recording additional herbaceous layer species not observed on the transect, as well as presence and approximate canopy cover of woody species. Shrubs and trees were recorded separately, with trees being defined as woody species more than 5 m tall. The total number of trees was further divided into three diameter-at-breast-height (DBH) classes (less than 23 cm, 23-38 cm, and greater than 38 cm) and the number of snags, or dead standing trees, was noted.

All vegetation species observed during surveys are listed in Appendix D, with both common and scientific names.

RESULTS

Riparian Avian Point Count Species Richness and Abundance

A total of 48 species were detected along West Stillwater Creek in Ross Ranch during point counts in 2016 (see Appendix B for complete list of species, scientific names, and 4-letter code abbreviations). Cliff Swallow was the most frequently encountered species, followed by California Quail, American Goldfinch, and Anna’s Hummingbird (Figure 1).

P a g e | 9 Figure 1. Number of individuals detected, per point per visit, (within 50 m of observer) along West Stillwater Creek at Ross Ranch in 2016.

Four of the seven California Partner’s in Flight riparian focal species were not detected along West Stillwater Creek in 2016 (Figure 2). The three that were detected (Common Yellowthroat, Black-headed Grosbeak, and Tree Swallow) were in significantly lower abundance than population targets.

Figure 2. Riparian focal species average bird abundance index (± 1 Standard Error) with nesting habitat along West Stillwater Creek within Ross Ranch in 2016, and California Partner’s in Flight population targets.

2.0

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8CL

SWCA

QU

AMGO

ANHU

LEG

OCA

LTCO

YEW

EKI

WEB

LW

ESJ

BUSH

BHCO

ATFL

OAT

IBE

WR

NU

WO

MO

DOEU

STAC

WO

TRES

WBN

UN

RWS

BLPH

BHGR

Index of Abundance

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8

BHCO³

TRES

SPTO¹²

YWAR¹

YBCH¹

BHGR

COYE

SOSP¹West Stillwater CreekAbundancePop Target Abundance

Early Successional

Mid-Successional

Late Successional

Parasitic Species

¹ No detections along West Stillwater Creek. ² No population target available. ³ Population target = 0.

P a g e | 10 Rangeland Avian Point Count Species Richness and Abundance

A total of 52 species were detected within the rangeland at Ross Ranch (Appendix B). Acorn Woodpecker was the most frequently detected species followed by European Starling, Ash-throated Flycatcher, and White-breasted Nuthatch (Figure 3).

Figure 3. Number of individuals detected, per point per visit, (within 100m of observer) at the Ross Ranch rangeland in 2016.

Oak woodland focal species abundance indices within rangeland at Ross Ranch exceeded California Partner’s in Flights population targets for canopy-nesting and understory-nesting species (Figure 4). Of the mid-canopy-nesting species, White-breasted Nuthatch exceeded the population target, Western Bluebird met the population target, and Oak Titmouse was significantly less than the population target. Shrub-nesting species were entirely absent. The invasive, non-native species, European Starling, was more abundant within Ross Ranch rangeland than all oak woodland focal species except for Acorn Woodpecker.

The rangeland points 5, 7, 10, 11, 14, and 16 had the greatest number of oak woodland species present (Appendix C).

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

ACW

OEU

STAT

FLW

BNU

OAT

ICL

SWW

EKI

AMGO

LEG

OTR

ESHO

FIN

UW

OBH

CORW

BLCA

QU

ANHU

MO

DO BTPI

YEW

ALA

SPW

EBL

HOW

RBA

RSN

OM

OCA

LTBU

SHYB

CHSP

TOGT

GRBE

WR

BRBL

DOW

O

Index of Abundance

P a g e | 11 Figure 4. Oak Woodland focal species average bird abundance index (± 1 Standard Error) with nesting layer within the Ross Ranch rangeland in 2016 and California Partner’s in Flight population targets.

Rangeland Soil Properties

Soil samples were collected at rangeland monitoring points 3, 11, 13, and 14 (Appendix A). All points were determined to be of a loam nature: points 3 and 14 were loam; point 11 was silty loam, and point 13 was clay loam (Figure 5).

We measured a moderate amount of variation in water infiltration rates across the four sampling points. Point 3 had the longest water infiltration rate and point 14 had the shortest (Figure 6). We are unaware of broadly accepted targets for infiltration time, but overall, faster infiltration times indicate lower soil compaction and more capacity for the soil to support seedling germination and root growth.

The NRCS Soil Quality Test Kit Guide’s target bulk densities for loam soils observed at Ross Ranch is 1.4 g/cm3 or lower. Bulk density values observed above this target are indicative of compacted soils, which can inhibit seedling germination and root growth. Points 3 and 11 had higher than ideal bulk densities, while points 13 and 14 were within the range of ideal bulk density for loam soil types (Figure 7).

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

EUST³

CAQU²

LASP

WESJ¹

BGGN¹

HUVI¹²

WEBL

OATI

WBNU

ATFL

ACWO

NUWO

YBMA¹²

Ross Abundance

Pop Target Abundance

Upper Canopy

Mid-Canopy

Shrub Layer

Understory

Invasive Species

¹ No detections within Ross Ranch rangeland. ² No population target available. ³ Population target = 0.

P a g e | 12 Point 14 had the highest percentage of carbon at the 0-10 cm depth at 3.4%, followed by point 13 at 2.5%, point 3 at 1.9%, and point 11 at 1.8% (Figure 8). Points 14 and 2 had the highest percentage carbon at the 10-40 cm depth at 1.1%, followed by points 11 and 13 at 0.9%.

Figure 5. Soil texture amassed from sample points at Ross Ranch, 2016.

Figure 6. Water infiltration rates of the second trial at the four sampling points from Ross Ranch, 2016. Points indicate average infiltration time for 5 subsamples at each point. Vertical lines show the range of time at each point.

P a g e | 13 Figure 7. Bulk densities of 4 samples from Ross Ranch, 2016. Points indicate average bulk density for 5 subsamples at each point. Vertical lines show the range of bulk density at each point.

Figure 8. Black points show percent organic carbon within 0-10 cm soil depth and 10-40 cm soil depth, amassed from sample points at Ross Ranch, 2016. For regional context, gray points show soil carbon across other Rangeland Monitoring Network sampling locations throughout California rangelands.

Vegetation Composition and Cover

One-hundred one plant species were identified across Ross Ranch during 2016 surveys, including thirty native species (see Appendix D for a complete list of species, including

P a g e | 14 scientific names). Of herbaceous plants, soft chess was the most commonly encountered species, comprising 21% of all observations, followed by ripgut brome at 17%, yellow star-thistle at 7%, wild oat at 6%, and spreading hedge parsley at 4% (Figure 9). Looking at individual points, soft chess was the most common species at point ROSS-03 and point ROSS-11 at 39% and 33%, respectively (Figure 10). Ripgut brome was the most common species at point ROSS-14 at 35%. An unknown (presumed) non-native grass was the most common species at point ROSS-13 at 12%.

Ten woody plants were encountered during surveys in 2016. Blue oak was by far the most common tree species (Figure 11). Of the shrubs, poison oak was the most common, followed closely by blue oak and manzanita (Figure 12). Point ROSS-03 had no shrub or tree species within a 50 m radius. The majority of trees at points ROSS-13 and ROSS-14 were within the smallest DBH size class of <23 cm (Figure 13). The majority of trees at point ROSS-11 were in the middle DBH size class of 23-38 cm, followed by the largest DBH size class of >38 cm.

Point ROSS-13 had the greatest percentage of bare ground at 8%, followed by ROSS-14 at 3%, ROSS-3 and ROSS-11 at 2% (Figure 14). Point ROSS-14 had the greatest percent litter at 88%, followed closely by point ROSS-13 at 86% (Figure 15). Points ROSS-11 and ROSS-03 both had 67% litter.

Figure 9. Percent vegetation composition of top layer of LPI surveys across four survey points at Ross Ranch, 2016.

0%

5%

10%

15%

20%

25%

soft chess ripgut brome yellow star-thistle

wild oat spreadinghedgeparsley

P a g e | 15

Figure 10. Percent vegetation composition of top layer of LPI survey at 4 survey points at Ross Ranch, 2016.

0%

10%

20%

30%

40%

50%

soft chess yellow star-thistle

ripgut brome carpet clover vetch

ROSS-03

0%

5%

10%

15%

20%

25%

30%

35%

soft chess wild oat yellow star-thistle

ripgut brome rose clover

ROSS-11

0%2%4%6%8%

10%12%14%

unknowngrass

ripgut brome dogtail grass spreadingheadgeparsley

suckling clover

ROSS-13

0%

10%

20%

30%

40%

ripgut brome soft chess spreadinghedgeparsley

vetch italian thistle

ROSS-14

P a g e | 16

Figure 11. Average percent absolute cover of tree species from 4 survey points at Ross Ranch, 2016.

Figure 12. Average percent absolute cover of shrub species from 4 survey points at Ross Ranch, 2016.

Figure 13. Tree DBH class size distribution by point at Ross Ranch, 2016.

0%

5%

10%

15%

20%

25%

30%

Blue Oak Valley Oak Gray Pine Oregon Ash

0%1%2%3%4%5%6%7%

0

50

100

150

200

250

300

ROSS-03 ROSS-11 ROSS-13 ROSS-14

DBH LT 23cm DBH 23cm To 38cm DBH GT 38cm

P a g e | 17

Figure 14. Percent bare ground by point at Ross Ranch, 2016.

Figure 15. Percent litter by point at Ross Ranch, 2016.

DISCUSSION

In 2016, we successfully collected baseline data at Ross Ranch to help inform management decisions and over time, evaluate the effects of those decision and impacts from public use. These data can also be used to help inform a grazing plan and identify areas that would benefit most from focused restoration actions.

West Stillwater Creek Riparian

The scarcity of riparian focal species along West Stillwater Creek is a strong indication that the habitat is not providing adequate food, shelter, or nesting locations to support the majority of breeding riparian species. Although no formal vegetation surveys were

0

2

4

6

8

10

ROSS-03 ROSS-11 ROSS-13 ROSS-14

% Bare Ground

0

20

40

60

80

100

ROSS-03 ROSS-11 ROSS-13 ROSS-14

% Litter

P a g e | 18

conducted along West Stillwater Creek, a cursory visual inspection shows that the vegetation is sparse and patchy along the Ross Ranch reach of the creek. The majority of vegetation that is present is largely lacking the structural complexity one would expect to see in a healthy riparian habitat, including emergent sedges, early successional willows, dense understory shrubs, vines (such as blackberry, grape, and pipevine), and mature overstory trees, including cottonwoods, alders, and Oregon ash.

Small patches of complex riparian habitat are still present along West Stillwater Creek, particularly moving downstream towards Shasta College, and can serve as a good reference for designing a riparian restoration. While a large scale, creek-wide restoration effort would be ideal, the avian population and other wildlife would also benefit from smaller more concentrated restoration efforts. Initial restoration efforts would be best targeted towards areas that would connect existing habitat patches and/or expand patch size.

Rangeland

The abundance and richness of birds within the Ross Ranch rangeland overall indicates a healthy and diverse breeding bird population and associated healthy oak woodland. Four of the five most frequently detected species within the rangeland were California Partner’s in Flight oak woodland focal species and were most likely nesting at the property.

While there appeared to be an overall decline in Acorn Woodpecker numbers in California’s Great Valley in 2016 (Point Blue unpublished data), this species was present in good numbers at Ross Ranch, and was in fact the most commonly encountered species on the property. The abundance of this and other primary-cavity nesting species such as Nuttall’s Woodpecker indicate that the number of large diameter (greater than 38 cm) trees at Ross Ranch appears sufficient. These large trees are primarily blue oak within the oak woodland on the northern part of the property, and primarily valley oak along the old irrigation canals and fence lines that meander across the property. Gray pine and standing snags are used preferentially by Acorn Woodpeckers as granary tree sites in Northern California (Gutiérrez and Koenig 1978), but only made up a small percent of overstory trees at Ross Ranch. Retention of standing snags and recruitment of gray pine should be promoted.

P a g e | 19

While some data suggests Lark Sparrow are in decline in much of Northern California (Sauer et al. 2000), there appears to be a healthy population breeding at Ross Ranch. The abundant litter layer at Ross Ranch interspersed with small patches of bare ground is well suited for this ground nesting species. However, this species also relies on bunch grasses to help conceal their nests (Bock and Webb 1984), which is relatively sparse at Ross Ranch. Native bunch grass restoration within the oak savannah or grassland portions of the ranch would benefit this and other ground-nesting and grassland-specific avian species.

There was a noticeable absence of shrub-nesting, oak woodland focal species including Blue-gray Gnatcatcher, Hutton’s Vireo, and Western Scrub-Jay. Blue-gray Gnatcatcher and Hutton’s Vireo commonly nest in small trees and tall shrubs while Western Scrub Jay nests almost exclusively in shrubs within 2-4 m off the ground (Ritter 1983). The relative scarcity of shrubs at Ross Ranch is most likely limiting these species ability to nest at the property. The absence of Western Scrub Jay is especially alarming as they are one of the best oak dispersers in California (Scott 1990). Common Northern California oak woodland shrubs such as Ceanothus spp., western redbud, toyon (Heteromeles arbutifolia), coffeeberry (Rhamnus californica), and wild rose (Rosa californica) should be encouraged at Ross Ranch.

European Starling, an introduced invasive species, was the second most abundant species within the rangeland. European Starling is an aggressive competitor for cavities in oak woodland, and will readily evict other species from nesting cavities (Feare 1984; Kerpez and Smith 1990). As the majority of birds that use oak woodlands are cavity-nesting species (Wilson et al. 1991), reducing attractants for European Starlings at Ross Ranch should be a priority. Starlings were especially abundant at points ROSS-02 and ROSS-08 (Appendix A). As European Starlings are heavily associated with human activities, the abundance of birds at ROSS-02 may be because of its proximity to the ranch headquarters and Shasta College, and perhaps due to the activities associated with the annual mud run that the McConnell Foundation hosts at Ross Ranch. Why the bird was so abundant at point ROSS-08 is less clear, but any attractants such as supplemental livestock feeding should be located away from the oak woodland areas.

Not surprisingly, points that were in more open grassland areas and further away from overstory oaks had fewer oak woodland focal species (Appendix C). Nonetheless, a

P a g e | 20

diverse array of avian species were detected at these points, including California Species of Special Concern Yellow Warbler and Yellow-breasted Chat. The patches of rose (Rosa sp.) at several of these points add structural complexity to the vegetation that allows a greater number of species to use these open grassland areas.

Relatively little bare ground was detected during surveys at Ross Ranch. Annual non-native grasses, including soft chess, ripgut brome, and wild oats dominated the rangeland. While they do not provide much structural complexity above or below ground, they are valuable forage species for both livestock and other ruminants and small mammals, and help protect the soil surface from the erosive potential of wind, rainfall and overland flow.

At least one nitrogen-fixing plant species was detected at each of the four sampling points, but cover was relatively low. Promotion of clovers and other nitrogen-fixing vegetation would benefit overall plant growth. Native grass and forb species, while present on Ross Ranch, were relatively scarce. Native bunchgrasses are important plant functional type, providing structural diversity above ground and promoting water infiltration and reduce bulk density below ground by way of their extensive, fibrous root systems. Targeted seedings and focused grazing management can improve native grass abundance.

While similar to other studies, the points sampled in more the open grassland at Ross Ranch (ROSS-03 and ROSS-11) had relatively low soil carbon, high bulk density, and slower water infiltration than those points sampled within the oak woodland (ROSS-13 and ROSS-14) (Dahlgreen et al. 2003, Silver et al. 2010). These grassland points also had fewer native herbaceous species (Appendix C). Combined, these indicators suggest that the grassland soils may not be supporting ecological processes as well as soils at the other sampling locations. Soils that are compacted and low in organic matter often do a poor job supporting seedling germination and root growth. Soils with high bulk density do not capture rainfall or storm water runoff effectively, reducing the time when soil-moisture is available to plants.

Management practices that encourage plant growth and plant inputs into the soil can improve soil compaction and organic matter concentrations. Targeted compost applications could improve soil quality and fertility in grassland areas at Ross Ranch. Improved soil quality should help promote perennial grass and forb establishment and

P a g e | 21

increase soil fauna (e.g. earthworms, ants), which in turn help decrease bulk density and increase water infiltration rates. In addition, grazing in a way that minimizes compaction and leaves plant residue will minimize soil organic carbon loss.

CONCLUSION

In 2016 we collected baseline avian, vegetation, and soil data from Ross Ranch. Baseline data can be used to evaluate management and public use changes, and can help guide grazing decisions and target areas for restoration or enhancement. While one should be cautious drawing conclusions from just one year of monitoring, our data suggests habitat and soil condition improvements ought to be considered. The habitat along West Stillwater Creek would be improved by connecting remnant riparian patches and widening the overall width of the riparian corridor. The rangeland habitat value at Ross Ranch could be improved by increasing the abundance of native shrubs and bunchgrasses. In addition, increasing soil organic carbon while lowering bulk density and water infiltration rates within the grassland would improve the ecological capacity of this habitat. Additional years of data collection are recommended in order to evaluate and help guide restoration and management changes.

P a g e | 22

LITERATURE CITED

Bock, C. E., and B. Webb. 1984. Birds as grazing indicator species in southeastern Arizona. Journal of Wildlife Management 48:1045-1049.

Brown, S., A. Dushku, T. Pearson, D. Shoch, J. Winsten, S. Sweet, and J. Kadyszewski. 2004. Carbon Supply fromChanges in Management of Forest, Range, and Agricultural Lands of California: Winrock International forCalifornia Energy Commission.

CalPIF (California Partners in Flight). 2002. Version 2.0. The oak woodland bird conservation plan: a strategy for protecting and managing oak woodland habitats and associated birds in California (S. Zack, lead author). Point Reyes Bird Observatory, Stinson Beach, CA. http://www.prbo.org/calpif/plans.html.

Cameron, D.R., J. Marty, R.F. Holland. 2014. Wither the rangeland?: protection and conversion in California’s rangeland ecosystems. PLoS ONE 9:e103468.

Chase, M. K. and G. R. Geupel. 2005. The use of avian focal species for conservation planning in California. In C. J. Ralph and T. D. Rich (eds.). Proceedings of the Third International Partners in Flight conference. USDA Forest Service Publication. Asilomar, CA.

Dahlgren, R.A., W.R. Horwath, K.W. Tate, T.J. Camping. 2003. Blue oak enhance soil quality in California oak woodlands. California Agriculture. 57:42-47.

DeLonge, M.S. , J. J. Owen, and W. L. Silver. 2014. Greenhouse Gas Mitigation Opportunities in California Agriculture: Review of California Rangeland Emissions and Mitigation Potential. NI GGMOCA R 4. Durham, NC: Duke University.

Feare, C. J. 1984. The starling. Oxford University Press, New York, New York, USA.

Gutierrez, J. R., and W. D. Koenig. 1978. Characteristics of storage trees used by acorn woodpeckers in two California woodlands. J. For. 76:162-164.

Herrick, Jeffrey E; Van Zee, Justin W; Havstad, Kris M; Burkett, Laura M; Whitford, Walter G. 2005a. Monitoring manual for grassland, shrubland and savanna ecosystems. Volume I: Quick Start. USDA-ARS Jornada Experimental Range.

P a g e | 23

Herrick, Jeffrey E; Van Zee, Justin W; Havstad, Kris M; Burkett, Laura M; Whitford, Walter G. 2005b. Monitoring manual for grassland, shrubland and savanna ecosystems Volume II: Design, supplementary methods and interpretation. USDA-ARS Jornada Experimental Range.

Kerpez, T.A, & N. S. SMITH. 1990. Nest-site selection and nest cavity characteristics of Gila Woodpeckers and Northern Flickers. Condor 92: 193-198.

NRCS. 1999. Soil Quality Test Kit. USDA. http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1044790.pdf

Porzig, E., N.E. Seavy, R. T. DiGaudio, C. Henneman, and T. Gardali. 2016. The Rangeland Monitoring Network Handbook V1.0. Point Blue Conservation Science, Petaluma, California.

Ralph, C.J., S. Droege and J.R. Sauer. 1995. Managing and Monitoring Birds Using Point Counts: Standards and Applications. Pages 161-168 in C. J. Ralph, J. R. Sauer, and S. Droege, Eds. Monitoring Bird Populations by Point Counts, USDA Forest Service, Pacific Southwest Research Station, General Technical Report PSW-GTR-149.

Ritter, Lyman V. 1983. Nesting Ecology of Scrub Jays in Chico, California. Western Birds: 14: 147-158.

Sauer, J. R., J. E. Hines, I. Thomas, J. Fallon, and G. Gough. 2000. The North American Breeding Bird Survey, Results and Analysis 1966-1991. Version 98.1, Laurel, MD: Patuxent Wildlife Research Center, Geological Survey, U.S. Department of the Interior. Available at: http://www.mbr-pwrc.gov /bbs/bbs.html.

Scott, T. 1990. Jays plant acorns. Oaks ‘n Folks. 5(2).

Silver, W.L., R. Ryals, and V. Eviner. 2010. Soil carbon pools in California’s annual grassland ecosystems. Rangeland Ecol Manage. 63: 128-136.

USDA. 2012. Census of Agriculture Highlights: Cattle Industry. http://www.agcensus.usda.gov/Publications/2012/Online_Resources/Highlights/Cattle/Cattle_Highlights.pdf

P a g e | 24

Wilson, A.W., P. Manley, and B.R. Noon. 1991. Covariance Patterns Among Birds and Vegetation in a California Oak Woodland. Pages 126-135 in: Proceedings of the Symposium on Oak Woodlands and Hardwood Rangeland Management. October 31 – November 2, 1990. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station. Gen. Tech. Rep. PSW-GTR-126.

P a g e | 25

APPENDICES

Appendix A. Point Blue study areas and point count locations at Ross Ranch for data presented in this report.

P a g e | 26

Appendix B. List of all species detected during point count surveys in 2016. Species excluded from point count data analyses are marked with an asterisk (*).

Rangeland

Code Common Name Scientific Name Code Common Name Scientific Name

CAGO Canada Goose* Branta canadensis BEWR Bewick's Wren Thryomanes bewickii CAQU California Quail Callipepla californica HOWR House Wren Troglodytes aedon WITU Wild Turkey Meleagris gallopavo WEBL Western Bluebird Sialia mexicana TUVU Turkey Vulture* Cathartes aura AMRO American Robin Turdus migratorius RTHA Red-tailed Hawk* Buteo jamaicensis NOMO Northern Mockingbird Mimus polyglottos KILL Killdeer* Charadrius vociferus EUST European Starling* Sturnus vulgaris BTPI Band-tailed Pigeon Patagioenas fasciata OCWA Orange-crowned Warbler Oreothlypis celata EUCD Eurasian Collared-Dove* Streptopelia decaocto YEWA Yellow Warbler Setophaga petechia MODO Mourning Dove Zenaida macroura YRWA Yellow-rumped Warbler* Setophaga coronata ANHU Anna's Hummingbird Calypte anna WIWA Wilson's Warbler* Cardellina pusilla ACWO Acorn Woodpecker Melanerpes formicivorus YBCH Yellow-breasted Chat Icteria virens NUWO Nuttall's Woodpecker Picoides nuttallii SPTO Spotted Towhee Pipilo maculatus DOWO Downy Woodpecker Picoides pubescens CALT California Towhee Melozone crissalis BLPH Black Phoebe Sayornis nigricans CHSP Chipping Sparrow Spizella passerina ATFL Ash-throated Flycatcher Myiarchus cinerascens LASP Lark Sparrow Chondestes grammacus WEKI Western Kingbird Tyrannus verticalis SAVS Savannah Sparrow* Passerculus sandwichensis CAVI Cassin's Vireo* Vireo cassinii GCSP Golden-crowned Sparrow* Zonotrichia atricapilla WAVI Warbling Vireo Vireo gilvus LAZB Lazuli Bunting Passerina amoena WESJ Western Scrub-Jay Aphelocoma californica RWBL Red-winged Blackbird Agelaius phoeniceus YBMA Yellow-billed Magpie Pica nuttalli BRBL Brewer's Blackbird Euphagus cyanocephalus TRES Tree Swallow Tachycineta bicolor GTGR Great-tailed Grackle* Quiscalus mexicanus CLSW Cliff Swallow Petrochelidon pyrrhonota BHCO Brown-headed Cowbird* Molothrus ater BARS Barn Swallow Hirundo rustica BUOR Bullock's Oriole Icterus bullockii OATI Oak Titmouse Baeolophus inornatus HOFI House Finch Haemorhous mexicanus BUSH Bushtit Psaltriparus minimus LEGO Lesser Goldfinch Spinus psaltria WBNU White-breasted Nuthatch Sitta carolinensis AMGO American Goldfinch Spinus tristis

P a g e | 27

West Stillwater Creek

Species Common Name Scientific Name Species Common Name Scientific Name

CAGO Canada Goose* Branta canadensis WEBL Western Bluebird Sialia mexicana MALL Mallard* Anas platyrhynchos NOMO Northern Mockingbird Mimus polyglottos CAQU California Quail Callipepla californica EUST European Starling* Sturnus vulgaris WITU Wild Turkey Meleagris gallopavo OCWA Orange-crowned Warbler Oreothlypis celata GBHE Great Blue Heron* Ardea herodias YEWA Yellow Warbler Setophaga petechia GREG Great Egret* Ardea alba COYE Common Yellowthroat Geothlypis trichas OSPR Osprey* Pandion haliaetus WIWA Wilson's Warbler* Cardellina pusilla EUCD Eurasian Collared-Dove* Streptopelia decaocto SPTO Spotted Towhee Pipilo maculatus MODO Mourning Dove Zenaida macroura CALT California Towhee Melozone crissalis ANHU Anna's Hummingbird Calypte anna SAVS Savannah Sparrow* Passerculus sandwichensis XXHU Unid. Hummingbird* Trochilidae sp. LISP Lincoln's Sparrow* Melospiza lincolnii ACWO Acorn Woodpecker Melanerpes formicivorus WCSP White-crowned Sparrow* Zonotrichia leucophrys NUWO Nuttall's Woodpecker Picoides nuttallii GCSP Golden-crowned Sparrow* Zonotrichia atricapilla DOWO Downy Woodpecker Picoides pubescens WETA Western Tanager* Piranga ludoviciana XXWO Unid. Woodpecker* Picidae sp. BHGR Black-headed Grosbeak Pheucticus melanocephalus BLPH Black Phoebe Sayornis nigricans RWBL Red-winged Blackbird Agelaius phoeniceus ATFL Ash-throated Flycatcher Myiarchus cinerascens BHCO Brown-headed Cowbird* Molothrus ater WEKI Western Kingbird Tyrannus verticalis BUOR Bullock's Oriole Icterus bullockii WESJ Western Scrub-Jay Aphelocoma californica HOFI House Finch Haemorhous mexicanus TRES Tree Swallow Tachycineta bicolor LEGO Lesser Goldfinch Spinus psaltria NRWS Northern Rough-winged Swallow Stelgidopteryx serripennis

CLSW Cliff Swallow Petrochelidon pyrrhonota

OATI Oak Titmouse Baeolophus inornatus

BUSH Bushtit Psaltriparus minimus

WBNU White-breasted Nuthatch Sitta carolinensis

BEWR Bewick's Wren Thryomanes bewickii

HOWR House Wren Troglodytes aedon

WEBL Western Bluebird Sialia mexicana

P a g e | 28

Appendix C. Oak woodland focal species abundance at each rangeland point count location at Ross Ranch, 2016.

P a g e | 29

Appendix D. All plant species encountered during vegetation surveys at Ross Ranch, 2016.

USDA Plant Code Scientific Name Common Name Native?

ROSS-03

ROSS-11

ROSS-13

ROSS-14

ACMI2 Achillea millefolium common yarrow Yes X

AGOSE Agoseris agoseris X AICA Aira caryophyllea silver hairgrass X X X

ANAR Anagallis arvensis scarlet pimpernel X X ANAR7 Anthoxanthum aristatum annual vernalgrass X X X

ANOD Anthoxanthum odoratum sweet vernalgrass X ARCTO Arctomecon bearpoppy X ARCTO3 Arctostaphylos manzanita X

ASTERA Asteraceae family X X X

AVBA Avena barbata slender oat X AVFA Avena fatua wild oat X X X X

BORAG Borago borage X X X

BRDI2 Brachypodium distachyon purple false brome X BRNI Brassica nigra black mustard X X

BRASSI Brassicaceae family X BRMA Briza maxima big quakinggrass X X

BRMI2 Briza minor little quakinggrass X X X X

BRDI3 Bromus diandrus ripgut brome X X X X

BRHO2 Bromus hordeaceus soft brome X X X X

BRRU2 Bromus rubens red brome X CAPY2 Carduus pycnocephalus Italian plumeless thistle X X X

CAAT25 Castilleja attenuata attenuate Indian paintbrush Yes X CESO3 Centaurea solstitialis yellow star-thistle X X X

CEGL2 Cerastium glomeratum sticky chickweed X X X

CECAT Cercis occidentalis Western Redbud X CHLOR3 Chlorogalum soapplant X

P a g e | 30

USDA Plant Code Scientific Name Common Name Native?

ROSS-03

ROSS-11

ROSS-13

ROSS-14

CHPO3 Chlorogalum pomeridianum wavyleaf soap plant Yes X COAR4 Convolvulus arvensis field bindweed X X CRAN11 Crucianella angustifolia narrowleaf crucianella X CYEC Cynosurus echinatus bristly dogstail grass X X

DAPU3 Daucus pusillus American wild carrot Yes X DICA14 Dichelostemma capitatum bluedicks Yes X DICAC5 Dichelostemma capitatum ssp. capitatum bluedicks Yes X DIMU5 Dichelostemma multiflorum roundtooth snakelily Yes X X X

ELGL Elymus glaucus blue wildrye Yes X ERBO Erodium botrys longbeak stork's bill X X

ERMO7 Erodium moschatum musky stork's bill X FRLA Fraxinus latifolia Oregon ash Yes X GALIU Galium bedstraw X X X GAPH2 Gastridium phleoides nit grass X GEDI Geranium dissectum cutleaf geranium X X

GEMO Geranium molle dovefoot geranium X HOMA2 Hordeum marinum seaside barley X X

HOMU Hordeum murinum mouse barley X X X

HYPE Hypericum perforatum common St. Johnswort X HYGL2 Hypochaeris glabra smooth cat's ear X HYRA3 Hypochaeris radicata hairy cat's ear X X X

JUNCU Juncus rush X LEONT Leontodon hawkbit X LOLIU Lolium ryegrass X X

LOPEM2 Lolium perenne ssp. multiflorum Italian ryegrass X LONIC Lonicera honeysuckle X

LUPIN Lupinus lupine X MADIA Madia tarweed X X

P a g e | 31

USDA Plant Code Scientific Name Common Name Native?

ROSS-03

ROSS-11

ROSS-13

ROSS-14

MALVA Malva mallow X MEPO3 Medicago polymorpha burclover X X

MECA2 Melica californica California melicgrass Yes X BOCAC Micropus californicus Q-Tips X MICA Micropus californicus Q-Tips Yes X MIGU Mimulus guttatus seep monkeyflower Yes X

NAPU4 Nassella pulchra purple needlegrass Yes X ODHA Odontostomum hartwegii Hartweg's doll's-lily Yes X

PETRO Petrorhagia pink X

PEDU2 Petrorhagia dubia hairypink X X PISA2 Pinus sabiniana California foothill pine Yes X PLGR Plagiobothrys greenei Greene's popcornflower Yes X

QUDO Quercus douglasii blue oak Yes X X

QULO Quercus lobata valley oak Yes X QUWI2 Quercus wislizeni interior live oak Yes X X

RAMU2 Ranunculus muricatus spinyfruit buttercup X RAOCO Ranunculus occidentalis var. occidentalis western buttercup Yes X

RAPHA Raphanus radish X X RASA2 Raphanus sativus cultivated radish X X

RUMEX Rumex dock X RUAC3 Rumex acetosella common sheep sorrel X RUSAD Rumex salicifolius var. denticulatus toothed willow dock Yes X

SACR2 Sanicula crassicaulis Pacific blacksnakeroot Yes X

SIDAL Sidalcea checkerbloom X SIMA3 Silybum marianum blessed milkthistle X SYAL Symphoricarpos albus common snowberry Yes X SYMO Symphoricarpos mollis creeping snowberry Yes X

TACA8 Taeniatherum caput-medusae medusahead X

P a g e | 32

USDA Plant Code Scientific Name Common Name Native?

ROSS-03

ROSS-11

ROSS-13

ROSS-14

TARAX Taraxacum dandelion X TORIL Torilis hedgeparsley X

TOAR Torilis arvensis spreading hedgeparsley X X X

TODI Toxicodendron diversilobum Pacific poison oak Yes X X X

TRIFO Trifolium clover X X X X

TRBA Trifolium barbigerum bearded clover Yes X

TRCA5 Trifolium campestre field clover X X

TRCY Trifolium cyathiferum cup clover Yes X TRDU2 Trifolium dubium suckling clover X X X X

TRGL4 Trifolium glomeratum clustered clover X X X

TRHI4 Trifolium hirtum rose clover X X X X

TRMO2 Trifolium monanthum carpet clover Yes X X TRVA Trifolium variegatum whitetip clover Yes X

VICIA Vicia vetch X X X

VISA Vicia sativa garden vetch X X X X

VIVI Vicia villosa winter vetch X X X X

VUBR Vulpia bromoides brome fescue X X VUMIM Vulpia microstachys var. microstachys desert fescue Yes X X

VUMY Vulpia myuros annual fescue X Grand Total 101 31 53 50 55 Native Total 30 3 8 12 15