Vegetation Distribution Comparison of Water Canyon and Quemada Watersheds on Santa Rosa Island, California

An Environmental Science and Resource Management Capstone Project

By: Aimee L. Newell Advisor: Dr. Linda O’Hirok

Submitted in partial fulfillment of the requirements for an Environmental Science and Resource Management Bachelors of Science degree from California State University Channel Islands

Spring 2016 (May 16, 2016) Newell 2

Abstract

Santa Rosa Island, Channel Islands National Park, was heavily grazed by cattle (Bos taurua), sheep (Ovis aries), elk(Cervus elaphus), and other non-native ungulates for 154 years, which degraded the island’s vegetation and stream geomorphology (Rick 2014). In 1998, the livestock was removed, and in 2011 the remaining non-native game animals were removed (Rick 2014), which allowed recovery of the land to begin. This study evaluated two watersheds on the island, Water Canyon and Quemada. Quemada Watershed had a restoration project with native species plantings in 1998, while the Water Canyon Watershed recovered naturally without any additional restoration projects. This research compared the vegetation distribution between the two watersheds. The Water Canyon watershed was further subdivided into four regions and the middle section directly compared to the Quemada watershed, due to its similar proximity, topography, and geomorphology. I surveyed the riparian communities and the terraces, identifying plant species and performing species diversity metric studies, including the ratio of species richness to total abundance, species evenness and heterogeneity. No significant difference was found in the overall diversity metric studies between the Water Canyon and Quemada watersheds, but the specific categorical vegetation distributions varied among these two watersheds. There was no statically significant difference in the percent of bare ground for the two watersheds (p=0.585), but the low percentages of 2% for Quemada and 5% for Water Canyon coupled with the increases in vegetation and species richness indicate regrowth on the island since the removal of the grazers. This has led to increased stability of the stream channel and overall improvement in the functionality of the watershed.

Keywords: Vegetation, Channel Islands, Water Canyon, Quemada, Soil, Erosion, Substrate, Terraces, Stream Channel, Grazing Newell 3

Introduction

The earth has a growing human population, and in order to meet the demand for resources there needs to be an increase in food and material resource production (Vitousek et al 1997). However, the earth is a closed system and has a finite amount of resources (Nelson et al. 2003). Consequently, humans are causing negative ecological impacts to the Earth by altering its ecosystems and biodiversity in order to keep up with today’s society and its mass consumption of resources. In most cases, it is difficult to quantify the ecological impacts made to the environment by humans and even more difficult to determine how the land will recover. This project will act as a case study to examine the ecological impacts that 154 continuous years of ranching has had on the vegetation in and on the function of two watersheds on Santa Rosa Island, California.

Santa Rosa Island

Figure 1 Map of Channel Islands National Park Created by: Aimee Newell

The Channel Islands National Park consists of five of eight islands off the coast of southern California (Schumann et al. 2014), including Santa Rosa Island (SRI) which is 44 kilometers off the mainland of California (Hofman and Rick 2014). Adjacent to SRI is five kilometers to the west and eight kilometers to the east (Daily 1989). Additionally, SRI is the second largest of the Channel Islands, with an area of 217 Newell 4

km2 (Hofman and Rick 2014). The island has a Mediterranean climate with dry summers with occasional fog and cool rainy winters. The main sources of water on the island are from the winter rains and through fog capture (Daily 1987). SRI has a mild topographic terrain (Kennett 2005) with landscapes that are primarily rolling hills and grasslands (Daily 1989). The climate influences different island ecosystems; the plants on the island grow in different ecosystems including coastal strands, coastal bluffs, grasslands, coastal sage scrub, chaparral, woodlands, pine forests, riparian and marsh ecosystems (Daily 1987).

Island History

Formation of Islands

The Channel Islands were created through tectonic uplift, faulting, as well as rising and falling sea levels (Schumann et al. 2014). They were previously connected to the mainland as a peninsula approximately 33.9 million to 200,000 years before present (Thorne 2007). Then during the Mesozoic era (252-66 million years ago) there was plate tectonic activity, illustrated in Figure 1a, that caused part of the Transverse Range on the North American plate to break off and rotate (Bartolomeo and Longinotti 2010). The constant moving of the plates caused the formation of the Santa Rosa Island Fault during the Miocene epoch (23-5.3 million years ago) (Kennett 2005), resulting in an east-west striking fault (Schumann et al. 2014).

During the island's formation, fluctuations in sea level caused the land to submerge. Sea levels declined around 20,000 years ago, allowing the northern islands to be connected as a land mass known as Santa Rosae (Figure 1b), which was only eight kilometers from the mainland. Later, during the Holocene Epoch (12,000-11,000 years ago), the islands shifted into their present day location (Rick 2005). Marine terraces that can be found along the landscape were formed during the rise and fall of sea levels over time. These terraces formed topsoil over the bedrock that allowed for organisms to inhabit it (Schumann et al. 2014). Due to the island being fully submerged over the course of its formation, all of the terrestrial biota that originated from the mainland was lost. Subsequently, the biotas on the islands must have arrived over water (Thorne 2007). Therefore, the island has a lower species diversity than the mainland following the island biogeography theory (MacArthur and Wilson 1967). Newell 5

Figure la Rolaliun ef Transverse Range (Party lumeu riiui l.imglhottl 2010) h'iyiirH lb Santa Sysaa land mass Chumash ~13,000 ybp-1816

Humans have inhabited SRI for at least 13,000 years, dating back to when the first known human remains, , were discovered (Orr 1962). There were Chumash artifacts found in close proximity to the remains suggesting that this human was among them. During the time when the Chumash lived on the island, the largest mammals were the island fox and the spotted skunk. The Chumash also introduced dogs to the island that accompanied them for thousands of years (Hofman and Rick 2014).

The Chumash were known for their arts, storytelling, and hunter-gatherer practices (Rick 1992). The Chumash made fishing hooks from abalone shells along with canoes from sea lion skins and redwood, which floated southward in the oceans currents. Nearly all the food the Chumash consumed was raw (Bowers 1996). The Chumash’s main consumption was marine resources with terrestrial plants supplementing their meals (Erlandson et al. 1999). Preserved charcoal suggests that the Chumash used burning for their agricultural purposes to enhance plant growth (Timbrook 2007). The Chumash also planted plants from the mainland and other islands (Rick et al. 2014). They used plants as a source of food and medicine (Timbrook 2007). The history of the island's land use dates back to the Chumash era, when it is estimated that human alterations to the land and vegetation began.

Carrillo Era 1843-1859

The ranching era on Santa Rosa Island began on October 3rd, 1843 when the Carrillo brothers were granted ownership of the island from Mexico (Allen 1996). In 1844, they introduced 270 cattle (Bos taurua), nine horses (Equus caballus), two rams (Ovis aries), and 51 ewes (Ovis aries) to the island (Daily 1989). They also built the first house on the island in 1855 (Vail and Daily 1989). By 1856, the island’s animal population had grown to 2,300 sheep, 8,000 cattle, and 235 horses (Allen 1996). The introduction of non-native grazers started the degradation of the island's vegetation and ecosystems. Newell 6

More Era 1858-1901

In 1858, the next ranching era began when the previous owner Carrillo became ill and sold his livestock to the More family. The More family primarily used the island as a sheep ranch (Allen 1996). During this era, there were more than 100,000 sheep on the island, (Daily 1989) and 1,200 sheep were being killed per day (Allen 1996). Alexander P. More, the sole owner, passed away in 1893, leaving the island to John F. More. John F. More was a neglectful owner and let the sheep run freely on the island (Allen 1996). The destruction to the land led to the new ownership of the island.

Vail and Vickers Era 1901-2011

In 1901, the Vail and Vickers families became the third private owners of the island. The Vail and Vickers families purchased the island in poor condition from the More family (Allen 1996). They removed the sheep to let the grass grow (Allen 1996) and to act as a conservation effort for the island (Hillinger 1996). However, the same year they stocked the island with 1,891 cattle (Allen 1996). In the early 1930’s, the families introduced deer from Arizona and elk from Washington with the intention of opening a private hunting reserve on the island (Woolley 1996). The Vail and Vickers families saw the island face harsh consequences as a resulting of land degradation by sheep grazing and severe drought conditions, often forcing the family to cut the grazing season short (Bowers 1996).

National Park Service Era 1986-Present

In 1986, the National Park Service (NPS) signed an agreement and purchased the land for $30,000,000 from the Vail and Vickers families. Reluctant to sell, the Vail and Vickers families finally sold with the agreement of being able to use the land for 25 more years. There were contingencies with the agreement that the Vail and Vickers had to follow the Special Use Permits that were granted by the NPS, allowing grazing and hunting to occur on the National Park premises but open to renegotiation every five years. In 1992, the Special Use Permit was revised to require enhancement of the rangeland and revegetation of the grasslands. This new plan also acknowledged the impacts grazers had on riparian stream channel ecosystems by prescribing construction of fences in these areas (Rosenlieb et al. 1995). Due to the dry weather and limited amount of water resources on the island, the grazers tended to use the riparian areas excessively (Stoddard et al. 1990). The excessive use of these areas resulted in unlawful amounts of bacteria and sediment discharge into state waters, which was a violation of the Regional Water Quality Control Plan for the Central Coast Basin. In May 1995, there was a Cleanup and Abatement Order (95-064) directed at the Channel Islands National Park to reduce the discharge from SRI. The order directed the NPS to draft a plan by July 1995 to correct this issue by targeting riparian grazing and road management practices. The riparian areas on SRI were then evaluated to see if they could keep grazers on the island while being able to meet the water quality goals (Rosenlieb et al. 1995). After the Abatement Order, the island failed to increase water quality, which led to the removal of all the cattle and a quarter of the deer population in 1998 (Wagner et al. 2004). The remaining deer and elk from the reserve were removed in 2011 (Rick 2014). Newell 7

Although the land is currently owned by the NPS who is focusing on preservation of the land, a century and a half of heavy ranching has caused substantial damage and alteration to the island ecosystems due to the introduction of non-native grazers, woody species used for firewood, and man-made roads and fences along the landscapes. The grazers trampled the land and consumed the vegetation down to the roots. This stress has caused erosion, soil compactions, and a loss of organic compounds in the soil (Rick et al. 2014). Soil is the base for an ecosystem, providing structure for plants to grow and allowing for decomposition and nutrient cycling (Tracy and King 2010). The conservation of healthy soil on the island has been a losing battle because there has been so much damage to it that it no longer contains the nutrients or natural conditions necessary for plant growth (Wright 1989). As a consequence, non-native annual grasses have been introduced extensively as they spread seeds easily and are able to survive in these rugged conditions. The ranching era resulted in a shift of ecosystems from chaparrals to non-native grasslands. Since the shift in ecosystems, the island’s soil is not as stable and prone to erosion (Tracy and King 2010).

Project Objectives

As stated earlier, this project will serve as a case study for the NPS on the vegetation distribution of two watersheds on the island, Water Canyon and Quemada. Water Canyon watershed is unique because the Santa Rosa Island Fault runs through the lower reaches. The lowest reaches of the watershed are on the north side of the fault and the rest of Water Canyon and Quemada are on the south side of the fault. The two watersheds were both impacted by the history of the island's land use. The grazers had access to both watersheds, which is evident from the corrals, visual degradation of the land and terracettes on hillsides (illustrated in Figure 2), and animal remains dispersed throughout the watersheds. Additionally, both watersheds contain streams which were classified as non-functioning in 1995. Water Canyon and Quemada’s streams had the lowest water quality out of all the streams on the island. In 1993-1994, Water Canyon’s stream produced the highest amount of fecal discharges, 1501 MNP/100ml, while Quemada’s stream produced second highest, 1249 MPN/100ml (Rosenlieb et al. 1995).

Figure 2 Photograph of a grazed hillside in Water Canyon Watershed Taken by: Aimee Newell Newell 8

Figure 3 Map of Santa Rosa Island highlighting Water Canyon Watershed and Quemada Watershed Created by: Aimee Newell

One of the main goals of this project was to establish baseline data for Water Canyon watershed and continue data collection on Quemada watershed. Previous studies have been conducted on Quemada watershed in 1998, 1999, 2002 (NPS 2004), and 2014 by other ESRM capstone students. The data collected is valuable to the NPS in the early stages of the island's recovery process so that future projects can evaluate the rate of recovery and determine if any restoration projects are necessary. Identifying and quantifying the vegetation distribution will contribute to the knowledge of the historical ecology of these watersheds. Studying the biodiversity and developing an understanding of both original and current species in the environment is critical to the conservation and recovery of an ecosystem.

This study looked at the vegetation distribution by identifying trends in vegetation on the terraces and in riparian communities within Water Canyon and Quemada watersheds. Since the removal of the non-native ungulates beginning in 1998, Water Canyon began its recovery process by attempting to remove specific man-imposed land alterations. Also in 1998, Quemada watershed had a single restoration project with native species plantings (NPS 2004). The goal of this study was to compare the two watersheds’ vegetation to see if there is any significant difference in species diversity, cover, and regrowth between the two and to evaluate whether either watershed is in need of any restoration or whether past restoration efforts have been successful. In order to analyze the vegetation distribution, the longitudinal slope, stream channel slope and shape, and substrate were all considered. Newell 9

Due to the close proximity of the two watersheds, I hypothesize that, despite the Quemada restoration efforts, the vegetation distribution of Water Canyon and Quemada watersheds will be similar. As the restoration in Quemada watershed was only a single planting project, it was unable to target the soil specifically. Soil is the basis for all ecosystems, and without a definite improvement in the Quemada soil over the Water Canyon soil, it is expected that the two watersheds will have comparable rehabilitation rates. A natural recovery process has been occurring in both watersheds for several years, allowing for rehabilitation of the vegetation cover leading to soil stabilization and improved ecosystem function. Consequently, I hypothesize that these watersheds will demonstrate rehabilitation but at similar rates despite the 1998 conservation project in Quemada.

Methods

Site Location

Figure 4 Map of Water Canyon and Quemada Watersheds with cross section locations Created by: Aimee Newell Newell 10

This study took place on the southeast side of Santa Rosa Island, California. The two watersheds used in this case study are adjacent to one another, with Water Canyon to the northwest of Quemada. Throughout the Water Canyon watershed there are 25 baseline data sites, ranging from the uppermost to the lowermost reaches, a 7.3-kilometer span. The sites were chosen after assessing aerial photographs with additional sites chosen unsystematically in the field based on surveyable accessibility and characteristic geomorphologic expression. These methods for choosing sites maintain a high validity and eliminate bias as they capture a variety of slopes, stream channel widths, and stream patterns (meander frequencies). The lowest reaches of the Water Canyon watershed are on the north side of the fault, and the Quemada and remaining Water Canyon watersheds are on the south side of the fault. I sectioned the Water Canyon into four sections: above the fault (sites north of the fault, numbered sites 1-6), below the fault (sites south of the fault, numbered sites 7-10), middle (sites in the geographic middle region of the defined watershed, numbered sites 11-20), and upper reaches (sites of highest elevation within the watershed, located to the west of the middle region and numbered sites 21-24). In the Quemada watershed, I surveyed the 10 sites that were established in 1998 by the NPS, which included the native plantings sites.

Field Methods

All the vegetation transects ran perpendicular to the stream channel, starting and ending on the terraces where the rebar was established. At each site, the transects were initiated by laying out the Keson 50-meter fiberglass transect tape along the ground across the stream channel. To begin the survey, I recorded the GPS coordinates using a Garmin Oregon 650t at the beginning and end of the transect. Using the GPS unit, the elevation was recorded at the beginning, end, and in the center of the stream channel. I used the point-intercept method to record plant species or ground cover data at discrete points every 30 centimeters. Every 30- centimeters along the transect tape, I recorded the substrate, location on the transect, plant species touching the stick, and height of all the species recorded. Specific transect locations included terrace (the flat elevated regions surrounding the stream channel), thalweg (the deepest portion of the stream channel), floodplain (the area adjacent to the stream channel and which floods during heavy storms), and bank (the area surrounding the stream channel, including the sloped areas leading to the terraces). Next, I classified all the plants to the genus as well as the known species, with the exception of grasses. I subdivided grasses into two main groups, annual or perennial. I further divided perennial grasses into bunch or spreading grasses. Newell 11

Figure 5 Shows an example of what a transect looked like (where it started and stopped)

Statistical Methods

I analyzed my data using Microsoft Office Excel. First, I performed individual site calculations for all 35 sites. I calculated the species abundance (total number of species present), species richness (number of unique species), and percent cover for all species and categorical vegetation. I then ran diversity metric statistics on evenness and heterogeneity. My first measure of species diversity was a ratio of the species richness (number of unique species at a transect) to the plant abundance (total number of plants found at a particular transect). In order to assess the evenness or variance of abundance between species, I used the Smith Wilson Evar equation, f s n \ E v a r = 1 — 2 / n arctan n \ l n ( x s) - £ l n ( x t)/S)2/S ^i=1 i=0 ' , where x is the species abundance and S is the number of unique species (Smith and Wilson 1996). To determine the heterogeneity, I used the Shannon-Wiener index, — ■ In(q-j-)), which is a measure of species richness and evenness, where N is the number of total unique species represented and n is the number of specific organisms within that species (Spellerberg and Fedor 2003).

After performing individual site calculations, I compared the vegetation data between the Quemada and Water Canyon watersheds. I used the Water Canyon sections as dummy variables and set Quemada as the intercept in my null hypothesis that assumed the Quemada baseline group to be zero. Using Quemada as my intercept, I was able to compare all sections at once by Newell 12

computing coefficients that were equivalent to the differences in mean, standard error, t-statistic, p-value, and 95% confidence intervals. I used this method to compare all the diversity metrics introduced above, including the species richness to plant abundance ratio and evenness and heterogeneity assessments.

Next, I calculated the vegetation percent cover for each unique species and the percent of land without any vegetation cover within each watershed section, again using Quemada as my intercept. The percent cover was calculated by summing the number of plants for each individual unique species and dividing it by the abundance of all species plus bare ground per site. The individual percent cover data points were then summed together by species category, including annual grasses, perennial grasses, forbs, phreatophytes, trees, and shrubs, with the individual species representing each group outlined in Appendix A. I then computed the coefficients, standard error, t-statistic, p-value, and 95% confidence intervals as described above.

Results

This case study compared the vegetation of Quemada watershed and Water Canyon watershed after the removal of grazers. The results were analyzed as baseline data for both watersheds. None of the historical data from Quemada watershed was used in the comparisons.

Diversity Metrics

Figure 6 Species Richness/ Plant Abundance Ratio

The chart above, Figure 6, displays the ratio of species richness or number of unique species to the total plant abundance found at all 35 sites used in this study. The sites are sectioned off with the same sections that were mentioned in the statistical methods above. This graph shows trends between the middle of Water Canyon watershed (sites 11-20) and the Quemada watershed. Due to similarities in grazing patterns and in substrate composition, the middle section of Water Canyon watershed was utilized for all comparisons with the Quemada watershed to best assess the recovery process of these two areas once affected by grazing. Newell 13

Species Richness/Piant Abundance Model P a ra m C o e ff SE t S ta t P -v a lu e L9 5 % U 9 5 % INTERCEPT 0.065 0.021 3.085 0.004 0.022 0.107 Above Fault 0.378 0.034 11.031 0.000 0.308 0.448 Below Fault 0.105 0.039 2.670 0.012 0.025 0.185 Middle -0.006 0.029 -0.211 0.834 -0.065 0.053 Upper 0.147 0.039 3.756 0.001 0.067 0.227 Table 1. Summary statistics for the species richness to plant abundance ratio; including the coefficient (equivalent to the differences in mean), standard error, t Stat, P-value, and 95% confidence intervals for all the parameters.

The “coeff’ in Table 1 above represents the difference in the species richness to plant abundance mean from the Quemada watershed intercept. The coefficient in all subsequent models contained in this analysis will also be calculated as the difference in mean from the Quemada intercept. The mean ratio for the species richness to plant abundance for the Quemada watershed is 0.65 with a standard error of 0.021. All of the p-values in the table for the species richness/plant abundance model and for the remaining models are a test between Quemada and that specific section of Water Canyon. The above fault section in Water Canyon has a mean species richness to plant abundance ratio of 0.443, a standard error of 0.034, and a p-value of <0.001. The below fault section in Water Canyon has a mean of 0.17, a standard error of 0.039, and a p-value of 0.012. The middle section of Water Canyon has a mean of 0.059, a standard error of 0.029, and a p-value of 0.834. The upper reaches section of Water Canyon has a mean of 0.212, a standard error of 0.039, and a p-value of 0.001.

Figure 7 Average species richness to plant abundance comparison between Middle Water Canyon and Quemada Newell 14

Figure 7 illustrates the ratio of average species richness to total plant abundance for the sites in the middle Water Canyon watershed and the Quemada watershed. There is no significant difference between the species richness to plant abundance ratio in the two watersheds, as demonstrated by the p-value of 0.834.

Evar Model P a ra m C o e ff SE t S ta t P -v a lu e L9 5 % U 9 5 % INTERCEPT 0.368 0.034 10.965 0.000 0.299 0.436 Above Fault 0.419 0.055 7.659 0.000 0.308 0.531 Below Fault 0.219 0.063 3.494 0.002 0.091 0.347 Middle 0.006 0.046 0.133 0.895 -0.088 0.101 Upper 0.251 0.063 3.997 0.000 0.123 0.379 Table 2. Summary statistics to test for the evenness; including the coefficient (equivalent to the differences in mean), standard error, t Stat, P-value, and 95% confidence intervals for all the parameters.

Evaluated via the Smith Wilson EVAR, the mean evenness for the Quemada watershed is 0.368 with a standard error of 0.034. The above fault section in Water Canyon has a mean of 0.787, a standard error of 0.055, and a p-value of <0.001. The below fault section in Water Canyon has a mean of 0.587, a standard error of 0.063, and a p-value of 0.002. The middle section of Water Canyon has a mean of 0.374, a standard error of 0.046, and a p-value of 0.895. The upper reaches section of Water Canyon has a mean of 0.619, a standard error of 0.063, and a p-value of <0.001.

Figure 8 Average Evenness, measured in Evar, comparison between Middle Water Canyon and Quemada Newell 15

Figure 8 illustrates the average evenness, Smith Wilson Evar, for the sites in the middle Water Canyon watershed section and in the Quemada watershed. The p-value (0.895) proves that there was no significant difference in the species evenness between the two watersheds. Heterogeneity Model P a ra m C o e ff 5E t S t a t P -v a lu e L9 5 % U 95 % INTERCEPT 1,929 0.077 24,908 0.000 1.771 2.087 Above Fault 0.031 0.126 0.242 0.810 -0.228 0.289 Below Fault -0.007 0.145 -0.051 0.959 -0.303 0.288 Middle -0.214 0.107 -2.000 0.055 -0.432 0.005 Upper -0.015 0.145 -0.107 0.916 -0.311 0.280 Table 3. Summary statistics to test for the heterogeneity; including the coefficient (equivalent to the differences in mean), standard error, t Stat, P-value, and 95% confidence intervals for all the parameters.

Evaluated using the Shannon-Wiener index outlined in the methods above, the mean heterogeneity for the Quemada watershed is 1.929 with a standard error of 0.077. The above fault section in Water Canyon has a mean of 1.96, a standard error of 0.126, and a p-value of 0.810. The below fault section in Water Canyon has a mean of 1.922, a standard error of 0.145, and a p-value of 0.959. The middle section of Water Canyon has a mean of 1.715, a standard error of 0.107, and a p-value of 0.055. The upper reaches section of Water Canyon has a mean of 1.914, a standard error of 0.145, and a p-value of 0.916.

Figure 9 Average Heterogeneity, measured using the Shannon-Wiener Index, comparison between Middle Water Canyon and Quemada Newell 16

Figure 9 illustrates the average heterogeneity, Shannon-Wiener index, for the sites in the middle Water Canyon watershed and Quemada watershed. The p-value (0.055) proves that there was no significant difference between the two watersheds.

Categorical Vegetation Cover

The percent cover for each species was calculated and summed according to the categories listed in Appendix A. The forbs had the widest variety of species with the most common species being the Baccharis glutinosa Pers., Daucuspusillus, Jaumea Canosa,, Stephanomeria sp. and Salicornia pacifica. The phreatophytes included Typha domingensis and Esquisetum laevigatum. The trees included Salix lasiolepis Benth., Salix exigua and Heteromeles arbutifolia, The bushes included Baccharis pilularis, Isocoma menziesii, Rhus integrifolia, and Artemisia Californica.

Figure 10 Average Categorical Vegetation Percent Cover for Middle Water Canyon and Quemada Watershed

Figure 10 depicts the summed categorical vegetation percent covers within the Quemada watershed and the middle section of Water Canyon watershed. In the Quemada watershed, forbs were the predominant vegetation type with a percent cover of 33%, followed by the perennial and annual grasses both with a percent cover of 21%. In the middle section of the Water Canyon watershed, the annual grasses predominated with a percent cover of 34%, followed by the forbs and perennial grasses with percents of 17% and 13%, respectively.

Annual Grasses Model P a ra m C o e ff SE t S t a t P -v a lu e L9 5 % U 9 5 % INTERCEPT 0.209 0.037 5.661 0.000 0.133 0.284 Above Fault -0.171 0.060 -2.832 0.008 -0.294 -0.048 Below Fault -0.096 0.069 -1.391 0.174 -0.237 0.045 Middle 0.135 0.051 2.646 0.013 0.031 0.239 Upper 0.047 0.069 0.682 0.500 -0.094 0.188 Table 4. Summary statistics to test for annual grass percent cover; including the coefficient (equivalent to the differences in mean), standard error, t Stat, P-value, and 95% confidence intervals for all the parameters. Newell 17

The mean percent coverage for the annual grasses in the Quemada watershed is 20.9% with a standard error of 0.037. The above fault section in Water Canyon has a mean of 3.8%, a standard error of 0.060, and a p-value of 0.008. The below fault section in Water Canyon has a mean of 11.3%, a standard error of 0.069, and a p-value of 0.174. The middle section of Water Canyon has a mean of 34.4%, a standard error of 0.051, and a p-value of 0.013. The upper reaches section of Water Canyon has a mean of 25.6%, a standard error of 0.069, and a p-value of 0.500.

Figure 11 Average percent cover of annual grasses comparison of Middle Water and Quemada

Figure 11 illustrates the comparison of average annual grasses percent cover for the sites in the middle section of the Water Canyon watershed and in the Quemada watershed. The p- value (0.013) proves that there was a significant difference between the two watersheds.

Perennial Grasses Model P a ra m C o e ff SE t S t a t P -v a lu e L9 5 % U 9 5 % INTERCEPT 0.209 0.023 9.185 0.000 0.163 0.256 Above Fault -0.169 0.037 -4.542 0.000 -0.245 -0.093 Below Fault -0.069 0.043 -1.611 0.118 -0.156 0.018 Middle -0.079 0.032 -2.518 0.017 -0.144 -0.015 Upper -0.114 0.043 -2.668 0.012 -0.201 -0.027 Table 5. Summary statistics to test for perennial grass percent cover; including the coefficient (equivalent to the differences in mean), standard error, t Stat, P-value, and 95% confidence intervals for all the parameters. The mean percent coverage for the perennial grasses in the Quemada watershed is 20.9% with a standard error of 0.023. The above fault section in Water Canyon has a mean of 4.0%, a Newell 18 standard error of 0.037, and a p-value of <0.001. The below fault section in Water Canyon has a mean of 14.0%, a standard error of 0.043, and a p-value of 0.118. The middle section of Water Canyon has a mean of 13.0%, a standard error of 0.032, and a p-value of 0.017. The upper reaches section of Water Canyon has a mean of 9.5%, a standard error of 0.043, and a p-value of 0.012.

Figure 12 Average percent cover of perennial grasses comparison of Middle Water and Quemada

Figure 12 illustrates the comparison of the average perennial grasses percent cover for the sites in the middle section of the Water Canyon watershed and in the Quemada watershed. The p-value (0.017) proves that there was a significant difference between the two watersheds.

Forb Model P a ra m C o e ff SE t S t a t P -v a lu e L9 5 % U 9 5 % INTERCEPT 0.329 0.028 11.694 0.000 0.271 0.386 Above Fault -0.201 0.046 -4.369 0.000 -0.294 -0.107 Below Fault -0.183 0.053 -3.479 0.002 -0.291 -0.076 Middle -0.159 0.039 -4.080 0.000 -0.238 -0.079 Upper -0.021 0.053 -0.400 0.692 -0.128 0.086 Table 6. Summary statistics to test for forb percent cover; including the coefficient (equivalent to the differences in mean), standard error, t Stat, P-value, and 95% confidence intervals for all the parameters.

The mean percent coverage for forbs for Quemada watershed is 32.9% with a standard error of 0.028. The above fault section in Water Canyon has a mean of 12.8%, a standard error of 0.046, and a p-value of <0.001. The below fault section in Water Canyon has a mean of 14.6%, a standard error of 0.053, and a p-value of 0.002. The middle section of Water Canyon has a mean Newell 19 of 17.0%, a standard error of 0.039, and a p-value of <0.001. The upper reaches section of Water Canyon has a mean of 30.8%, a standard error of 0.053, and a p-value of 0.692.

Figure 13 Average percent cover of forbs comparison of Middle Water and Quemada

Figure 13 illustrates the comparison of the average forbs percent cover for the sites in the middle section of the Water Canyon watershed and in the Quemada watershed. The p-value (<0.001) proves that there was a significant difference between the two watersheds.

Phreatophyte Model P a ra m C o e ff SE t S ta t P -v a lu e L 9 5 % U 9 5 % INTERCEPT 0.120 0.020 6.042 0.000 0.080 0.161 Above Fault -0.015 0.033 -0.456 0.652 -0.081 0.052 Below Fault 0,042 0.037 1.128 0.268 -0.034 0.118 M iddle 0.003 0.028 0.113 0.911 -0.053 0.059 Upper -0.073 0.037 -1,956 0.060 -0.149 0.003 Table 7. Summary statistics to test for phreatophyte percent cover; including the coefficient (equivalent to the differences in mean), standard error, t Stat, P-value, and 95% confidence intervals for all the parameters.

The mean percent coverage for phreatophytes for the Quemada watershed is 12.0% with a standard error of 0.020. The above fault section in Water Canyon has a mean phreatophyte percent coverage of 10.5%, a standard error of 0.033, and a p-value of 0.652. The below fault section in Water Canyon has a mean of 16.2%, a standard error of 0.037, and a p-value of 0.268. The middle section of Water Canyon has a mean of 12.3%, a standard error of 0.028, and a p- value of 0.911. The upper reaches section of Water Canyon has a mean of 4.7%, a standard error of 0.037, and a p-value of 0.060. Newell 20

Figure 14 Average percent cover of phreatophytes comparison of Middle Water and Quemada Figure 14 illustrates the comparison of average phreatophyte percent cover for the sites in the middle section of the Water Canyon watershed and in the Quemada watershed. The p-value (0.911) proves that there was no significant difference between the two watersheds.

Tree Model P a ra m C o e ff SE t S t a t P -v a lu e L 9 5 % U 9 5 % INTERCEPT 0.010 0.009 1.155 0.257 -0.008 0.029 Above Fault 0.008 0.015 0.537 0.595 -0,022 0.038 Below Fault 0.013 0.017 0.745 0.462 -0.022 0.047 Middle -0.003 0.012 -0.209 0.836 -0.028 0.023 Upper -0.010 0.017 -0.617 0.542 -0.045 0.024 Table 8. Summary statistics to test for tree percent cover; including the coefficient (equivalent to the differences in mean), standard error, t Stat, P-value, and 95% confidence intervals for all the parameters.

The mean percent coverage for trees for the Quemada watershed is 1.0% with a standard error of 0.009. The above fault section in Water Canyon has a mean of 1.8%, a standard error of 0.015, and a p-value of 0.595. The below fault section in Water Canyon has a mean of 2.3%, a standard error of 0.017, and a p-value of 0.462. The middle section of Water Canyon has a mean of 0.7%, a standard error of 0.012, and a p-value of 0.836. The upper reaches section of Water Canyon has a mean of 0%, a standard error of 0.017, and a p-value of 0.542. Newell 21

Figure 15 Average percent cover of trees comparison of Middle Water and Quemada Figure 15 illustrates the comparison of average percent tree cover for the sites in the middle section of the Water Canyon watershed and in the Quemada watershed. The p-value (0.836) proves that there was no significant difference between the two watersheds.

Shrub Model P a ra m C o e ff SE t S t a t P -v a lu e L9 5 % U 9 5 % INTERCEPT 0.101 0.028 3.633 0.001 0.044 0.157 Above Fault 0.010 0.045 0.217 0.830 -0.083 0.102 Below Fault 0.124 0.052 2.383 0.024 0.018 0.230 Middle 0.076 0.038 1.977 0.057 -0.003 0.154 Upper -0.038 0.052 -0.725 0.474 -0.144 0.068 Table 9. Summary statistics to test for shrub percent cover; including the coefficient (equivalent to the differences in mean), standard error, t Stat, P-value, and 95% confidence intervals for all the parameters.

The mean percent coverage for shrubs for the Quemada watershed is 10.1% with a standard error of 0.028. The above fault section in Water Canyon has a mean of 11.1%, a standard error of 0.045, and a p-value of 0.830. The below fault section in Water Canyon has a mean of 22.5%, a standard error of 0.052, and a p-value of 0.024. The middle section of Water Canyon has a mean of 17.7%, a standard error of 0.038, and a p-value of 0.057. The upper reaches section of Water Canyon has a mean of 6.3%, a standard error of 0.052, and a p-value of 0.474. Newell 22

Figure 16 Average percent cover of shrubs comparison of Middle Water and Quemada Figure 16 illustrates the comparison of average shrub percent cover for the sites in the middle section of the Water Canyon watershed and in the Quemada watershed. The p-value (0.057) proves that there was no significant difference between the two watersheds.

Bare Ground Model P a ra m C o e ff SE t S t a t P -v a lu e L 9 5 % U 9 5 % INTERCEPT 0.021 0.035 0.601 0.552 -0.051 0.093 Above Fault 0.537 0.058 9.339 0.000 0,420 0.655 Below Fault 0.169 0.066 2.569 0.015 0.035 0.304 Middle 0.027 0.049 0.552 0.585 -0.073 0.126 Upper 0.209 0.066 3.167 0.004 0.074 0.343 Table 10. Summary statistics to test for percent bare ground; including the coefficient (equivalent to the differences in mean), standard error, t Stat, P-value, and 95% confidence intervals for all the parameters.

The mean percent of bare ground for Quemada watershed is 2.1% with a standard error of 0.035. The above fault section in Water Canyon has a mean of 55.8%, a standard error of 0.058, and a p-value of 0.000. The below fault section in Water Canyon has a mean of 19.0%, a standard error of 0.066, and a p-value of 0.015. The middle section of Water Canyon has a mean of 4.8%, a standard error of 0.049, and a p-value of 0.585. The upper reaches section of Water Canyon has a mean of 23.0%, a standard error of 0.066, and a p-value of 0.004. Newell 23

Figure 17 Average percent cover of bare ground comparison of Middle Water and Quemada Figure 17 illustrates the comparison of average bare ground cover for the sites in the middle section of the Water Canyon watershed and in the Quemada watershed. The p-value (0.585) proved that there was no significant difference between the two watersheds.

Summary Statistics Significantly Different? Species Richnes5/Plant Abundance N Diversity Metric Evenness N Heterogeneity N Annual Grasses Y Perennial Grasses Y Forbs Y Categorical Vegetation Preatophytes N Trees N Shrubs N Bane Ground N Figure 18 Summary of all the statistics comparing the middle section of Water Canyon to the Quemada watershed Newell 24

Discussion

Water Canyon Site Sections

Above the fault

The above fault section, located north of the fault in the Water Canyon watershed contained sites 1-6. This area of the watershed had the shortest transects with an average length being 1,195 centimeters. The sites also did not capture the upper main terraces, only the low terraces and stream channel. The surveys eliminated the main terraces because they were 20-30 meter cliffs that were not surveyable. The fault has caused a change in topography and substrate from the north side to the south side of the fault. Due to uplifting, the substrate in this portion of the watershed was primarily exposed bedrock or bedrock with a layer of topsoil (Dibblee et al. 2002).

Below the fault

The below fault section in Water Canyon watershed contained sites 7-10. Similar to above the fault, this portion of the watershed did not capture the main terraces due to the difficult terrain. In this portion of the watershed, the average length of the transects was 1,583 centimeters. Being in close proximity to the fault, these sites had substrates that were primarily bedrock and rocky soils.

Middle Reaches

The middle section of Water Canyon watershed, sites 11-20, varied drastically from the areas adjacent to the fault. This portion of the watershed had no bedrock exposure and the substrate was primarily loamy soils on the terraces with clay in the stream channel. The transects in this portion of the watershed captured the main terraces and were much wider. The average length of these transects was 3,365 centimeters. The land surrounding the stream channel was much flatter than the lower reaches of the watershed. There is a corral located near site 11 and a road that led to the stream channel in this portion of the watershed. It is evident that this portion of the watershed was the area primarily affected by grazing. Access by ungulates was easiest to the streams and hillsides in these areas of the watershed.

Upper Reaches

The upper reaches section of Water Canyon watershed include sites 21-24. This portion of the watershed had the highest upstream to downstream slope of 6.9 percent, whereas the rest of the watershed had an average of percent slope of 2.7. The transects in this region had an average length of 1,628 centimeters, with the transects decreasing in length while increasing in elevation. Similarly, transects at higher elevations in the watershed exhibited more unconsolidated soil. Newell 25

Middle of Water Canyon to Quemada Comparison

The middle section of the Water Canyon watershed was the most comparable to the Quemada watershed. As both areas are on the same side of the fault, they have similar loamy soils on the terraces and clay in the stream channels. It is evident that both areas were affected by grazing as the ungulates had easy access to the stream channel with corrals and roads located in both regions. The middle Water Canyon and Quemada watersheds both captured meander frequencies and a variety of cross-sectional slopes that are comparable to one another, indicating prolonged topographical and geographical similarities, allowing for similar grazing patterns. Because these two regions exhibited the greatest evidence of grazing consequences and the most comparable terrain, they were the primary focus of this paper’s comparisons.

It is unknown if the grazers were in the other sections within the Water Canyon watershed due to the difficult terrain. The substrate composition, longitudinal slope, and cross­ sectional slope (capturing the upper main terraces) in the above fault, below fault and upper sections of Water Canyon were not comparable to Quemada. Tests were conducted on these regions comparing these sections to Quemada, as shown in Tables 1-10, but they will not be included in the final conclusions of this study because this study focuses on the recovery of the land post-grazing, and these regions were not heavily impacted by the grazers.

Diversity Metrics

There are specific trends in the relationship of species richness to plant abundance ratio within the Water Canyon watershed. Above the fault had the highest of these ratios closest to the ocean. There was a steady decline in the ratio moving southward until the middle section of the watershed was achieved, where the ratio reached a minimum averaging at 5.9%, roughly equivalent to that of the Quemada watershed at 6.5%. Then, moving westward into the upper reaches section, this ratio began to again increase. This observed pattern could have resulted from differences in substrate within these regions. Adjacent to the fault, in the above and below sections, there was bedrock exposure that did not occur in the middle or upper sections of the watershed. This allowed for greater species diversity, as different niches were open. Species such as Eriogonum sp., Coreopsis gigantean, Salvia brandegeei, and Dudleya sp. don’t require loamy soils and can grow in thin layers of soil or in bedrock (Nobel and Zutta 2007). The middle section of Water Canyon consisted of loamy soils where annual and perennial grasses thrive. The excessive amount of grasses eliminates available niches resulting in a decrease in species richness (Sala et al. 1989). There is an outlier in this ratio at site 21 in the upper section before the gradual incline of the ratios. Although this site was closest to the middle section, it was located downstream of a confluence, allowing for increased moisture. Additionally, the substrate at this site consisted primarily of unconsolidated slip sediments. Coupling the substrate and proximity to the confluence, this site had a much greater species richness due to more available niches, as indicated by the low grass percent cover. The remaining upper section, however, exhibited steady increases in the ratio as the elevation increased and substrate shifted from loamy soils to unconsolidated slip sediment. The Quemada watershed consisted of soils similar to that in the middle section of Water Canyon. There were also high percentages of grasses at the Quemada sites, following the pattern of decreased niche availability to allow for an increase in Newell 26

species richness. The accessibility of grazers to the middle of Water Canyon and Quemada has also impacted the species richness causing it to decrease with the shift in ecosystems from chaparrals to grasslands (Tracy and King 2010).

These statistics support my hypothesis that the middle section of the Water Canyon watershed and the Quemada watershed have comparable species diversity metrics due to similarities in accessibility, allowing for increased grazing, as well as a lack of available niches as a result of increased grass populations. The high species richness to total abundance ratio in the remaining Water Canyon sections also supports the claim that the above, below, and upper areas experienced limited grazing due to limited accessibility from increased slopes and elevations adjacent to the fault and within the upper reaches. T-tests revealed statistically significant differences in the species richness to abundance ratio for the above fault, below fault, and upper sections of Water Canyon as compared to Quemada with p-values of <0.001, 0.012, and 0.001, respectively; whereas the middle section and Quemada exhibited similar species richness to plant abundance patterns with a p-value of 0.834.

Similarly, the evenness model comparing Quemada to the above fault, below fault, middle, and upper sections of Water Canyon shows statistically significant difference between each of these regions, excluding the middle section, with p-values of <0.001, 0.002, 0.895, and <0.001, respectively. These regions have more equally distributed species than Quemada and the middle section of Water Canyon, where annual and perennial grasses and forbs predominate, followed by phreatophytes and shrubs and limited trees.

There was no significant difference in the species heterogeneity when comparing all regions of Water Canyon to Quemada. The heterogeneity assessed the species richness as coupled to the species distribution or evenness. While the above fault, below fault and upper sections of Water Canyon demonstrated significant differences in species evenness as compared to Quemada, the heterogeneity analyses were all comparable, indicating changes in species richness that led to an overall equilibrium in species heterogeneity. The above fault, below fault, and upper sites consisted of a greater number of unique species with decreased numbers of plants within each category and an overall even distribution, as compared to the Quemada watershed, which contained a smaller number of overall species, i.e. less species richness, and with a less even distribution among those species. In middle of Water Canyon and Quemada, these few particular species were annual grasses, perennial grasses, and Typha domingensis. Quemada also had an additional species, Jaumea canosa that was not found in middle Water Canyon.

Categorical Vegetation Cover

Annual and Perennial Grasses

Although the middle section of the Water Canyon and the Quemada watersheds exhibited similar species diversity metrics, the specific species comprising these two watersheds varied. There was a significant difference in the percent cover of annual grasses with a p-value of 0.013 and significantly more annual grass cover in the middle section of Water Canyon, 34%, as compared to Quemada, 21%. The majority of annual grasses in these watersheds were non-native Newell 27

species. Some of the species found in these watersheds were Bromus diandrus, Bromus madtridensis, Bromus hordeaceus, and Polypogon monspeliensis.

Similar to annual grass, perennial grasses also exhibited a significant difference in the percent cover between the Quemada and middle Water Canyon regions. Quemada had higher percent averages of perennial grasses, 21%, than Water Canyon, 13%, with a statically significant p-value of 0.017. The majority of perennial grasses found in both watersheds were spreading grasses found in the floodplain and stream channel. The two most common spreading grasses wereDistichlis spicata and Cynodon dactylon. However, Distichlis spicata was found more often in the Quemada watershed and Cynodon dactylon more commonly in Water Canyon. This difference in percent cover and specific species abundance could have resulted from Quemada’s closer proximity to the ocean, leading to more estuary-like conditions (NPS 2004). Distichlis spicata has a higher salinity tolerance than Cynodon dactylon (Marcum et al. 2005), allowing it to survive and thrive in Quemada, whereas theCynodon dactylon was only able to thrive in the less saline regions of the middle Water Canyon.

Perennial grasses live for many years and are able to develop deeper root systems than annual grasses, increasing soil stability and decreasing erosion. Therefore, perennial grasses are more likely to contribute positively to the overall function of the watershed with stream stability. While the precise reason for the significant increase in perennial grasses in the Quemada watershed as compared to the middle section of Water Canton is unclear, this could be indicative of varying susceptibility to the long-term consequences of grazing or varying rates of recovery. A possible restoration effort, however, could target the areas of Water Canyon and Quemada watersheds with high amounts of annual grasses by restoring them back to the native perennial vegetation.

Forbs

The Quemada watershed also had a significantly higher percent abundance of forb species, 33%, than the middle section of Water Canyon, 17%, with a p-value <0.001. As mentioned earlier, the sites in Quemada were closer to the ocean and had a higher salinity than those in the middle of Water Canyon. This results in variation of plant species in the watersheds. Quemada resulted not only in high percentages of spreading perennial grasses but also high amounts of saline-tolerant forbs. In these Quemada sites, the most common forb species were Jaumea canosa and Salicorniapacifica, both of which can withstand a high salinity and were not found in Water Canyon. The sites within the Quemada watershed with the highest forbs percent cover were located closest to the ocean and the smallest percent cover most inland, further supporting this conclusion. Additionally, forbs plants in both watersheds had the highest variation and diversity of any of the other categorical vegetation. This could be due to the fact that herbaceous plant seeds can persist in soils for decades (Wagner et al. 2004). During the ranching era, the grazers could have eaten all of the forb species but because of the seed bank, these species have been able to recover. Newell 28

Phreatophytes

The percent cover of phreatophytes was exactly the same in Quemada as in the middle of Water Canyon, 12%. The phreatophytes found in the transects are native to the island. Typha domingensis was found in both watersheds and was most common. There was only one site with a different phreatophyte, Equisetum laegvigatum,that grew in the middle of Water Canyon. At every site phreatophytes grew in the stream channel and thalweg, as they require water in order to survive. The growth of vegetation in the center of the stream channel slows the velocity of the stream channel and decreases sediment deposition. Additionally, Typha domingensis is known for helping with water quality as it filters contaminants (Abdel-Ghani 2009). The ranching era resulted in high amounts of fecal matter in both watersheds. This species has had a positive impact by initiating recovery of the water to lower levels of contaminants (NPS 2004).

Trees

There was also no significant difference between the percent tree cover in Quemada and the middle of Water Canyon, with both watersheds having only one percent tree cover but consisting entirely of native species. Salix lasiolepis Benth was the most common type of tree found in these watersheds. During the ranching era, the deer and elk consumed the seedlings, causing the population to decrease. Salix lasiolepis Benth and Salix exigua reproduce through wind-borne seeds and require bare, moist mineral soils to reproduce. The trees have had difficulty reproducing due to a lack of trees in these regions and are unable to reproduce off of a seedbank as were the forbs, resulting in a significantly delayed recovery process (Wagner et al. 2004). A future restoration project could target these species by planting offspring of island Salix lasiolepis Benth and Salix exigua. This could cause the stream channel to become more stable as the roots trap sediment. More trees would ultimately help with erosion, slow the stream’s velocity, and shade the stream channel lowering stream channel temperatures. Additionally, more trees would help capture more moisture from fog, which is a main source of water on the island. This would not only be beneficial to the individual tree but also to the surrounding vegetation in the ecosystem (Fischer et al. 2007).

Shrubs

There was no also no significant difference of shrub percent cover between Quemada and the middle of Water Canyon. However, the middle of Water Canyon had higher percentages of shrubs than Quemada, with average percent covers being 18% and 10%, respectively, with a p- value of 0.057. The low percent cover of shrubs in these watersheds is a result from the ranching era. The grazers often consumed plants to the roots, including shrubs (Moody 2000). Baccharis pilularis and Artemisia californica were the two most commonly occurring shrubs in these watersheds. Baccharispilularis are deep rooted plants with roots growing up to 3.2 meters (Canadell et al. 1996). These deep roots could potentially have increased their rate of recovery, due to persistent roots even after their shrubs were grazed. Conversely, Artemisia californica have shallow branching roots (Francis 2004). The variation of roots between the two species has resulted in individual niches which are not in competition with one another. In both watersheds it was common to find both Baccharis pilularis and Artemisia californica intermingled within the sites. The combination of both shrub species increases stability of soil on the terraces, banks, and Newell 29

on the floodplains. As soils are stabilized, there is a reduction in erosion. Similar to trees, shrubs also help capture fog, benefiting the surrounding vegetation as well.

Bare Ground

The middle of Water Canyon watershed and Quemada watershed had no significant difference for bare ground percent cover with a p-value of 0.585. Both watersheds had low average bare ground, 2% for Quemada and 5% for middle Water Canyon. As mentioned previously, there were significant amounts of sediment deposited into the ocean from both watersheds. This is indicative of prior high percentages of bare ground and erosion. The primary substrate in these regions is currently loamy soil, which is a clear indicator that there has been regrowth since the removal of the grazers. The regrowth of vegetation causes stability in the soil. Although both native and nonnative species were recorded in these watersheds, the regrowth of the species present causes stability and an overall improvement to the functioning of the watershed, allowing the watershed to transition back to its natural cycles.

Limitations of study

There were a few errors or areas of improvement with this study worth noting for future studies. Due to the high number of sites assessed and the logistical aspects of accessing these sites, the data was collected at various times of year. Having the data collected at different times could have caused seasonal errors with plant species. Additionally, this study categorized grasses to eliminate error, but this decreased the actual species richness per sample, as it did not account for the different species of grasses within those categories.

Conclusion

The middle section of the Water Canyon watershed and the Quemada watershed were both affected by grazing. The middle of Water Canyon had no active restoration attempts to the land after the removal of the ungulates and was left to recover naturally. The sites assessed in the Quemada watershed were subject to a one time planting after the removal of the cattle. Despite this restoration project, there were no significant differences in the diversity metric statistics between the Quemada and middle Water Canyon watersheds, supporting my hypothesis that the vegetation distributions between the two watersheds are not significantly different. This suggests that the one-time planting in the Quemada watershed was not successful, which could have been due to deer and elk populations that were still present on the island at the time. However, both watersheds have been recovering naturally since the stressors have been eliminated.

One of the goals of this paper was to determine whether either watershed was in need of restoration after comparing the two watersheds and to look at the overall improvement of these areas. It is well-known that these two regions faced severe consequences from prolonged grazing as evidenced by unlawfully high sedimentation deposits into the ocean and stream channels prior to the removal of the ungulates, indicating a loss of root systems to retain the soil, allowing it to be washed away. This study clearly reveals that despite having suffered such consequences, the Newell 30

land is naturally recovering. The sedimentation deposit rates into the ocean have decreased since the removal of the grazers (NPS 2004), indicating decreased erosion and greater soil stabilization. The results of this study suggest that the increased soil stabilization is a direct result of increased percentages of ground cover through the natural recovery process. The vegetation likely most involved in this recovery process includes annual and perennial grasses and forbs, as these plants had the highest percent covers. While this paper focused on diversity metrics and an examination of the categorical vegetation distributions, there were also significant differences in the specific species present at these sites, demonstrating varied recovery rates among those species as well as an increase in species diversity that suggests even greater ecosystem health. This increase in vegetation leads to increased stability of the stream channel, a reduction in water pollution, and overall improvement in the functionality of the watershed. Additionally, the percent of bare ground has significantly diminished to less than 5%, further evidencing the watershed’s overall recovery. To fully determine the extent at which either watershed is in need of a restoration project will require further study, as this study was baseline data and did not report on the rate of regrowth, rather on the presence of regrowth.

Although the rate of regrowth is unknown based off of this study, a few possible restoration efforts could be made on the non-native annual grasses, shrubs, and trees in these watersheds. Restoring non-native annual grasslands back to the perennial grasses or coastal sage scrub ecosystems would increase the complexity of the root systems, leading to greater stabilization of the hillsides, terraces, and banks within the watersheds. The planting of both shrubs and trees would impact the surrounding vegetation by aiding in soil stabilization, increasing fog capture providing one of the main sources of water, and providing shade cover to lower water temperatures, which improves water quality. The plantings of trees and shrubs should be the first considered restoration as it has the widest variety of positive impacts.

Opportunities for Further Research

One of the main goals of this project was to establish baseline data for the Water Canyon watershed. Baseline data on watersheds located on SRI are of interest to the NPS in the early stages of passive restoration. Future projects can establish baseline data in other watersheds. Now that baseline data is established in the Water Canyon watershed, future studies can repeat the research and examine the rate of recovery within the watershed. This type of future research will be able to look at how effective the recovery process is and if the NPS is in need of implementing any of the suggested restoration projects.

Another area for further research is to define how vegetation data is correlated with slope, elevation, and different physical aspects of the stream channel. At each of the 35 sites there were vegetation and geomorphology surveys that overlapped each other. The geomorphology data was collected using a Nikon 5.c Total Station. The geomorphologic cross-section would start with the rod directly in front of the Nikon 5.c Total Station and end on the opposite side of the stream’s terrace. The end result from a cross-section would produce the shape of the stream channel, using the distance from the Total Station and the elevation at that point, which was used in the analysis of the vegetation data. From this data, I calculated the slope at each location. Using the information I collected, location on the transect at each point and the elevations of the beginning and end of the transect, I estimated the slope for each of my sample locations. Unfortunately, this Newell 31 information was not instrumental to this study. However, future projects can specifically look at this data and examine whether the different species recorded have a correlation with slope.

Acknowledgements Thank you to Dr. Sean Anderson, Dr. Donald Rodriguez, and the ESRM program at CSU Channel Islands for providing the opportunity for students to conduct independent research. Thank you to the Santa Rosa Island Research Station, especially Dr. Cause Hanna, for helping with organizing the logistics of getting to and from the island, as well as helping get around the island. I would like to pay a special thanks to my advisor, Dr. Linda O’Hirok, who helped me devise and plan this entire capstone project. Thank you to the CSUCI Minigrant who funded the project. Thank you to Dr. Brett Hartman, Samantha Sellers, Casey Lysdale, Jeyla Fendi, Reily Pratt, Brenna Pratt, Kevin Gaston, Tyler Fuller, Sean Clark, Patrick Costa, Laura Powell, and Tyler Nichols who sacrificed an entire weekend to help collect data. Thank you to Matthew Wiers for the help with the statistical analysis. Newell 32

Work Cited

Abdel-Ghani, N., A. Hegazy, and G. El-Chaghaby. 2009. Typha domingensis leaf powder for decontamination of aluminum, iron, zinc and lead: Biosorption kinetics and equilibrium modeling. International Journal of Environmental Science & Technology 6:243-248.

Agenbroad, L. D., J. R. Johnson, D. Morris, and J. Thomas W. Stafford. 2005. Mammoths and Humans As Late Pleistocene Contemporaries on Santa Rosa Island. Institute for Wildlife Studies, Acata, California.

Allen, K. B. 1996. Ranching on Santa Rosa Island in Island of the Cowboys Santa Rosa Island. Santa Cruz Island Foundation, Santa Barbara, California.

Bartolomeo, E. S., and N. Longinottib. 2010. Tectonic history of the Transverse Ranges: Rotation and deformation on the plate boundary in Geology and Geomorphology of Eastern Santa Cruz Island. Department of Geology University California Davis, Davis, California.

Bowers, R. S. D. 1996. Santa Rosa Island in Island of the Cowboys Santa Rosa Island. Santa Cruz Island Foundation, Santa Barbara, California.

Canadell, J., R. Jackson, J. Ehleringer, H. Mooney, O. Sala, and E.-D. Schulze. 1996. Maximum rooting depth of vegetation types at the global scale. Oecologia 108:583-595.

Daily, M. 1987. California Channel Islands. McNally and Loftin Publishers, Santa Barbara, California.

Daily, M. 1989. Santa Rosa Island in Northern Channel Islands Anthology. Santa Cruz Island Foundation, Santa Barbara, California.

Dibblee, T., H. E. Ehrenspeck, D. Browne, K. Mitchell, and H. Chaney. 2002. Geology of Santa Rosa Island, California. Pages 115-126 in Proceedings of the Fifth California Islands Symposium, Santa Barbara, Santa Barbara Museum of Natural History.

Erlandson, J. M., T. C. Rick, R. L. Vellanoweth, and D. J. Kennett. 1999. Maritime Subsistence at a 9300 Year Old Shell Midden on Santa Rosa Island, California. Pages 255-265, Journal of Field Archaeology.

Fischer, D. T., and C. J. Still. 2007. Evaluating patterns of fog water deposition and isotopic composition on the California Channel Islands. Water Resources Research 43.

Francis, J. K. 2004. Wildland shrubs of the United States and its Territories: thamnic descriptions: volume 1. General Technical Report-International Institute of Tropical Forestry, USDA Forest Service. Newell 33

Hillinger, C. 1996. Santa Rosa Island in Island of the Cowboys Santa Rosa Island. Santa Cruz Island Foundation, Santa Barbara, California.

Hofman, C., and T. Rick. 2014. The Dogs of CA-SRI-2: Zooarchaeology, Diet, and Context of Canis familiaris from Santa Rosa Island, California, USA. Ethnobiology letters 5:65­ 76.

Kennett, D. J. 2005. The Island Chumash Behavioral Ecology of a Maritime Society. University of California Press, Berkeley and Los Angeles, California.

Marcum, K. B., M. Pessarakli, and D. M. Kopec. 2005. Relative salinity tolerance of 21 turf- type desert saltgrasses compared to bermudagrass. HortScience 40:827-829.

Moody, A. 2000. Analysis of plant species diversity with respect to island characteristics on the Channel Islands, California. Journal of Biogeography 27:711-723.

Nelson, M., J. Allen, A. Ailing, W. Dempster, and S. Silverstone. 2003. Earth applications of closed ecological systems: relevance to the development of sustainability in our global biosphere. Advances in Space research 31 :1649-1655.

Nobel, P., and B. Zutta. 2007. Rock associations, root depth, and temperature tolerances for the “rock live-forever,” Dudleya saxosa, at three elevations in the north-western Sonoran Desert. Journal of arid environments 69:15-28. NPS. 2004. Santa Rosa Island Water Quality Report; Final Completion Report. National Park Service.

Orr, P. C. 1962. Arlington Springs Man. Science 135:219-219.

Rick, T. C. 1992. Household and Community Archaeology at the Chumash Village of Niaqla, Santa Rosa Island, California. Journal of Field Archaeology 32 :243-263.

Rick, T. C., J. M. Erlandson, R. x. Vellanoweth, L, and T. J. Braje. 2005. From Pleistocene Mariners to Complex Hunter-Gatherers: The Archaeology of the California Channel Islands. Journal of World Prehistory 19:169-228.

Rick, T. C., T. S. Sillett, C. K. Ghalambor, C. A. Hofman, K. Ralls, R. S. Anderson, C. L. Boser, T. J. Braje, D. R. Cayan, R. T. Chesser, P. W. Collins, J. M. Erlandson, K. R. Faulkner, R. Fleischer, W. C. Funk, R. Galipeau, A. Huston, J. King, L. Laughrin, J. Maldonado, K. McEachern, D. R. Muhs, S. D. Newsome, L. Reeder-Myers, C. Still, and S. A. Morrison. 2014. Ecological Change on California's Channel Islands from the Pleistocene to the Anthropocene. Oxford University Press 64:680-692.

Rosenlieb, G., B. Jackson, C. Sellgren, J. Wolf, J. Wagner, J. Reiner, K. McEachern, and D. Pritchard. 1995. Federal interagency Riparian Assessment and Recommendations for Achieving Water Quality Management Goals, Santa Rosa Island, Channel Islands National Park. National Park Service. Newell 34

Sala, O. E., R. Golluscio, W. Lauenroth, and A. Soriano. 1989. Resource partitioning between shrubs and grasses in the Patagonian steppe. Oecologia 81:501-505.

Schumann, R. R., S. A. Minor, D. R. Muhs, and J. S. Pigati. 2014. Landscapes of Santa Rosa Island, Channel Islands National Park, California. 7:48-67.

Smith, B., and J. B. Wilson. 1996. A consumer's guide to evenness indices. Oikos:70-82.

Spellerberg, I. F., and P. J. Fedor. 2003. A tribute to Claude Shannon (1916-2001) and a plea for more rigorous use of species richness, species diversity and the ‘Shannon- Wiener’Index. Global ecology and biogeography 12 :177-179.

Stoddard, L. A., A. D. Smith, and T.W. Box. 1975. Range Management, 3rd edition. McGraw- Hill, New York. 532 pp.Thorne, R. F. 2007. The California Islands. Annals of the Missouri Botanical Garden 56:391-408.

Timbrook, J. 2007. Chumash Ethnobotany Plant Knowledge Among the of Southern California. Santa Barbara Museum of Natural History, Santa Barbara, California.

Tracy, B., and A. King. 2010. Soil formation on Santa Cruz Island: Influences of livestock on a developing landscape in Geology and Geomorphology of Eastern Santa Cruz Island. Hydrological sciences graduate group civil and environmental engineering University California Davis, Davis, California.

Vail, A., and M. Daily. 1989. Santa Rosa Island: Past, Present, and Future in Northern Channel Islands Anthology. Santa Cruz Island Foundation, Santa Barbara, California.

Vitousek, P. M., H. A. Mooney, J. Lubchenco, and J. M. Melillo. 1997. Human domination of Earth's ecosystems. Science277:494-499.

Wagner, J., M. Martin, K. R. Faulkner, S. Chaney, K. Noon, M. Denn, and J. Reiner. 2004. Riparian System Recovery after Removal of Livestock from Santa Rosa Island, Channel Islands National Park, California. United States Department of the Interior, National Park Service.

Woolley, W. 1996. Santa Rosa Island: An Introduction in Island of the Cowboys Santa Rosa Island. Santa Cruz Island Foundation Santa Rosa Island Chapter, Santa Barbara, California.

Wright, A. T. 1989. An Islandian on the Island in Northern Channel Islands Anthology. Santa Cruz Island Foundation, Santa Barbara, California. Newell 35

Appendix A

Plant Species Common Name Category Name Native? W att-j-t= A.;. c t 1 A .-; - Annua Q ~ ss p W/q 32 13 Spreading Peire n n"a Gnass p w/q 2 3 13 Bunch Pe -e in nial G nass p w/q 3 3 2 3 AchMeer mUafolium L Yarrow IFodb N W/Q 3 4 3 4 Arrsi.nckio sp. K d d eneck Farfc N q 10 5 A p icstruim irnqiJStjFi&Lijm V-uff. Mocc Pa_s ey Fo“b N W/Q 9 15 A rie rr)s in c o if or.n ice L e as. Sage brush Bushj N W/Q S3 2 5 Atripkx serriboasoio ft. Sr. AustraBanSaOt Bush Focb A w/q 15 2 5 Atriptex sp. Sa tBush Fo“b ? q 2 0 9 Beech oris aiati.noso Pars. Ya s h Baaccha*'s IFodb N W/Q 7 1 11 Beech oris piiufaris DC. Coyote Bush Bushj N W/Q 112 23 Cotysteaia rrocroszeolo(E G reen s jf Sru n w n itt Coast Miming Glory Fo“b N W/Q 3 1 5 C orduaspycnoephoias CtaEan Thistle IFodb A W/Q 3 7 2 3 C o rp o b robus d i Hen sis Sea IFng Ice plaint Focb A w 13 2 2 C irsiam w h o r e Spe a- Thistie Fo“b A W/Q 3 7 2 3 Coreopsis gigenzeo Cant Coreopsis Farfc N w 3 0 2 4 Cor erh ro e y .n s fiks§ An rfotic CoT Tcn Sandaste- Fo"b N W/Q IS 3 5 D onas pasiihis Arne* a n W idl Carnot Fo“b N W/Q IS 2 6 D u d e y e sp . band live foie veil Farfc N w 2 1 3 5 Epiobium can am Ca"fo"n"a Fusdhia Focb N w 2 5 3 5

EqjAsrrj.m )oe/:ootu rr Ho-asta' 5, Phreatophyte N w 103 13 E'igeron conodensis HoTeweedl Focb A W/Q 5 5 2 1 Eriogonam orboresce.ns £ G reens s and Buckwheat Focb N w 3 7 4 5 Enogonum sp. Buckwheat Sp. Fo“b N w 55 3 9 E rodiarr c icutarium CoadaO he iron b ibil Focb A q 10 5 here rorr e.'ss arbu zrfo)io “ oyon Tree N W/Q 5 3 13 Hirschfefdiein co.no W3d mustard Focb A W/Q 3 9 2 1 is o c o m o rre.n r e s : Ve nines13 go de n bLsh Bush N w 3 0 3 9 Jo-u m e o Co.nose Ma-jr SLTea Focb N q 2 0 9 Lapinas oJbifnons vor. duaiesi} Doug as si he r lupine Fo-b N W/Q 14 23 W o rm b u m vu ieere I. White ho’ehoundl IFoib A w 4 2 9 Medkxrga pofyrrorpho L B l ■ dowe r Focb A q 13 11 M im a h s aiittctiij Mon cey flower Focb N w 3 3 16 M im a ia s g v th e iu sDC. See p Mon « y fo w e - Fo-b N w 3 0 15

Ds s u do a .n -sq-.h alia rr rr icroceph chi rr (Nil ft.} .nA, dsrh. W u -fg htscudweed Fo“b N w 2 4 3 7 A hhiyicxiJus c o ifo m ic u flwith. s CaBfomia Buttercup Focb N q 23 2 9 ffJhiJ s inzearrfoiic Lemonade 5e~y Bush N w 7 0 4 6

Purrs x crispas Curly Dock Focb A W/Q 5 7 15 Soiicomio pocfico PickOe weed! Focb N q 19 6 So):x exiauc Sandbar W1 low Tree N w 5 5 12 5aBx )osio!ep:s Ee.nzh. Airayo W ilow Tree N W/Q 3 1 2 12 So) via bro.n de o se i [sand Sage Focb N w 5 7 2 9 sonduts asper Sow-thistle Focb A q 19 12 St rp-.hon orr er:o s p. B ro w n p lw K wnireCettuce Fo“b N w 5 9 23 Typho dorr inuen sis Cattais Phxeatophyte N W/Q 162 11 Vicia sp. Vetches Focb p W/Q 23 10 Figure 19 Species that were found at the 35 sites along with the category they were classified as, native (N) or non-native (A), the watershed that had them in the transects, the average height of the species, and the average slope the species were found.