evaluating the ability of the california rapid assessment method
TRANSCRIPT
1
Evaluating the Ability of the California Rapid Assessment Method (CRAM) to Capture Seasonal
Variability within the Kachituli Oxbow Wetland Restoration Site
By Leticia Morris
Environmental Studies Department
Environmental Policy Thesis
California State University, Sacramento
December 14, 2014
In thanks to Dr. Michelle Stevens for sharing her expertise in CRAM and providing me
invaluable feedback during this learning process.
Thanks also to Dr. Foran for providing much needed feedback during these revision stages
2
ABSTRACT
The California Rapid Assessment Method (CRAM) is a tool utilized for the assessment of
wetland restoration sites across California. Developed in collaboration of a broad range of state,
local and non-profit agencies, the CRAM is a level 2 component of the national EPA
monitoring framework guided by regulatory permitting and Water Quality Monitoring. To test
the CRAM’s applicability and ability to detect seasonal variability within wetland restoration
sites, the Kachituli Oxbow restoration site was chosen for this case study. The Kachituli
Restoration site was implemented in 1991 and has maintained success without outside water
inputs even through severe drought conditions experienced in Northern California. Given these
water constraints, the first CRAM was performed during the spring of 2014 and the second was
compared to the subsequent CRAM performed during the summer of 2014. The prediction was
that in light of drought conditions, the CRAM would be able to detect changes occurring at the
sight from season to season. Our findings suggest that because the overall CRAM scores
remained the same, either the CRAM may not be suitable for this application or that the changes
on-site were not sizeable to warrant sizeable changes in CRAM scores. However, because the
individual attribute scores did show fluxes, it can be inferred that the CRAM does still detect
seasonal variation. Ultimately, although the CRAM may not be applicable for detecting these
changes at a finer level than vegetative sampling, the CRAM did indicate that its scores across
seasons are consistent for their intended use as assessments of overall ecological functions.
Future studies at Kachituli may contribute data for long-term correlations. Long-term data may
be helpful in providing resources for continued management of the Kachituli Restoration sight.
3
Table of Contents
Abstract……………...…………………………………………………………………………………………………2
1 INTRODUCTION.……………………………………………………………..…………………………….4
1.1 Objectives…………………….…………………………………………………….…………………….4
2 SITE DESCRIPTION…………………………………….…………………………………….................4
2.1 Project Background………....…………………………………….………………...4
2.2 Climate and Hydrology……………………..………………………………………..6
2.3 Soils…………………………………………………………………………………...7
2.4 Historic Land-Use and Cultural Resources……………………………………..……8
2.5 Vegetation Design…………………………..…………..…………….…………….9
3 METHODS…….…………………………………………………………………………………………………10
3.1 California Rapid Assessment Method (CRAM)……….………..…………………………...…….10
4 RESULTS……………………………………………………………………………………………………….13
4.1 Soil Survey 2014………….....… ..………...………..……..…..………………………13
4.2 Spring 2014 CRAM Scores ..…………………..………………….……….………….15
4.3 Summer 2014 CRAM Scores ..………...…………..………………………………….16
5 DISCUSSION………………………………...………………………………………..………………………18
6 REFERENCES……………..………………………………………………………………………………….33
1.0 INTRODUCTION
4
1.1 OBJECTIVES
This assessment investigates the site conditions of the Kachituli Oxbow Mitigation
Project in Yolo County, California twenty years after its initial successful implementation.
Although this year marks the third year of an extreme drought experienced throughout
California, remarkably, 2014 has been the first year that the Kachituli Oxbow has gone dry.
Given these extreme drought conditions, it is predicted that other signs intra-annual variability
will be detected on site. Thereby, this study utilizes the California Rapid Assessment Method
(CRAM) to compare data collected during the spring 2014 growing season and the summer 2014
dry season. The goals of this comparison are to: characterize the range of variability that occurs
between seasons and assess the applicability of the CRAM as a tool for detecting seasonal
changes at the Kachituli Oxbow. It was hypothesized that: 1) the CRAM will capture seasonal
variability between spring and summer and 2) the CRAM (Attribute 4: Biotic Structure) will be
less accurate in detecting variability in vegetation communities than independent qualitative
vegetation analysis. This analysis may add to existing data utilized to maintain the success of
Kachituli’s long-term restoration.
2.0 SITE DESCRIPTION
2.1 PROJECT BACKGROUND
The Kachituli Oxbow Restoration Project is located east of the Sacramento International
Airport in Yolo County. It is located in close proximity to the Sacramento River nearest the
intersection of Road 22 and Interstate 5 This project was initiated in 1991 as mitigation for
habitat loss proposed at a nearby site. Although funded by the Lighthouse Marina and Riverbend
5
Development, this nearby project was never actually completed. Still the Kachituli Restoration
project was implemented (D. Kelley, Kelley and Associates, personal comm).
One of the main components of the Kachituli project was to construct an oxbow, or lake
that forms as meandering flows become disconnected from a river. Thereby, this restoration
project did not re-create an oxbow lake on an area that was previously connected to the river, but
rather, the project construction took place on land maintained for tomato crops. The planning of
the project consisted of restoration of over 110 acres of agricultural fields to woodland and
riparian habitat. The focus of the construction of these woodlands was directed toward the
preservation of habitats for the Valley Elderberry Longhorn Beetle (Desmocerus californicus
dimorphus) and the Swainson’s Hawk (Buteo swainsoni) (Green and Associates Kelley and
Associates, Thasos 1990). The Kachituli oxbow habitat restoration was the largest of its kind in
the Western United States (Hey and Philippi, 1999). Over twenty years later, as earlier
assessments have taken place, this restoration site is still functioning as a woodland and riparian
habitat corridor without outside irrigation (McGuirk, 2014).
U.S. Fish and Wildlife (USFWS) and the Army Corps approved the Lighthouse Marina
and Riverbend development to undertake the Kachituli restoration project on this site in Yolo
County because its site conditions were surveyed and found to be suitable for the restoration of
an oxbow. The 110 acres of agricultural area designated for this restoration project were
originally known as Amen Ranch. In total, Amen Ranch consisted of over 280 acres and so the
acreage that was neither serviced for the habitat creation by the Kachituli Restoration designers
nor the Army Corps was turned over to the USFWS to serve as additional habitat for waterfowl
in the Yolo Basin (Green and Kelley Associates, 1990; Hey and Phillipi, 99).
6
2.2 CLIMATE AND HYDROLOGY
The Kachituli restoration project resides adjacent to the levee side of the Sacramento
River basin watershed. Regional climate is characterized as Mediterranean with annual
precipitation estimated at nearly 18 inches (USCD, 2012). However, several reports have
characterized current precipitation patterns have reached a 20-year low as this is one of the many
regions within California that is experiencing a severe drought (Jackson et al, 2012).
Specific to monthly precipitation data for the site location in Woodland, the U.S Climate
Data (2014) estimates that the average rainfall of the winter months of December, January and
February has dropped from 2.86 inches in 2013 to 1.71 inches averaged for those same months in
2014. As for the average rainfall for the spring months of March, April and May, there has been
a drop form 1.24 inches in 2013 to 0.77 inches in 2014 (USCD, 2014). Furthermore, although
temperatures during summer months have typically been around 93-96 degrees Fahrenheit
(SRWP, 2014); long-term climate data indicated an upward trend in average temperatures in both
summer and winter months. This trend of decreasing precipitation and increased temperatures in
the northern California region is expected to continue as drought conditions persist in a region
experiencing the impacts of climate change (Jackson et al, 2012).
Kachituli resides alongside the region of the Sacramento River that begins at Shasta Lake
and drains further south into the Sacramento Delta before it reaches one of its main tributaries,
the American River (Ibid). However, although Kachituli rests within the boundary of Yolo
County that borders the Sacramento River, its hydrologic connection to this river has been
separated for nearly a century. The site rests on the floodplains of the Sacramento River; thereby,
because of its proximity to the levee, the Kachituli site would become inundated in the event of
7
an extreme flood. Thus, Kachituli is not directly subject to surface water conditions of the river;
rather, its primary water source is ground-water (Green and Kelley, 1990; Hey and Phillipi, 99).
2.3 SOIL SURVEY PRIOR TO RESTORATION PROJECT IMPLEMENTATION
Kachituli is composed of fertile alluvial soils that were deposited several thousand years
ago (Cultural Resources Unlimited, 1990). According to a 1972 site survey performed by the
Soil Conservation Service, the soil profiles were delineated as Sycamore Silty Clay Loam,
Sycamore Drained, Sacramento Clay, Sacramento Drained and Valdez soils (figure 1) (Green
and Kelley, 1990). Both Sycamore Silty Clay Loam and Sycamore Drained soils are
characteristic types that hold water well, and therefore tend not to drain quickly. Both of these
soils are types that you would find on alluvial fans, or landscapes onto which courser sediment
accumulates as streams flow. Similar to these clays, both types of Sacramento soils also have a
high water retention capacity, except these soils are usually found beneath the Sycamore clays.
Likewise, the Valdez soils tend to drain slowly; this soil series is also composed of more sandy
materials than the others identified within the Kachituli study area (Hey and Phillipi, 99).
Figure 1: Kachituli Soil Profile
(Hey and Philippi, 1999)
8
2.4 HISTORIC LAND USE AND CULTURAL RESOURCES
Before contact with Spanish and European conquistadors, the Kachituli study area was
once home to several indigenous peoples whose tending of the land dates back several hundreds
of generations. The greater Yolo County surrounding the site was tended by the Patwin, a tribe
who belong to the southern band of the Wintun Nation. The stewards of Kachituli, however,
were tended by the Nisenan Maidu (Cultural Resources Unlimited, 1990).
The Nisenan Maidu were known to be harvesters of many rhizomatous plants and several
types of acorns, nuts and berries. Historically, multitudes of plants and shrubs were respectfully
harvested in native communities within the Central Valley. Culturally important species include:
willow (Salix exigua, Salix laevigata, Salix lasiolepis, Salix lucida, Salix lucida), narrow-leaf
milkweed (Asclepias fascicularis), Indian hemp (Apocynum cannabinum), deer grass
(Muhlenbergia rigens), and Santa Barbara sedge (Carex barbarae), which were used for several
purposes, ranging from food and fiber to materials for basket-weaving (Stevens, 2004).
Although the Nisenan Maidu held claim to the western outlet of the Sacramento River,
collectively, the Patwin and the Nisenan Maidu shared access to the Sacramento River to harvest
Salmon and other shellfish. Also in the region of Kachituli, elk, deer and several other animals
were hunted for the sustenance of the community. In honor of theses historic tenders of this
study area, the designers of this mitigation project named the site “Kachituli” which was the
name of another Patwin community farther out in Woodland (Cultural Resources Unlimited,
1990).
Beginning in the mid 1960’s, the site was known as Amen Ranch and was recorded to
have been a hops farm; more presently, the site was managed as a tomato farm (Hey and Phillipi,
99). Before the site was sold in 1989 to Lighthouse Marina and Riverbend Development for
9
mitigation purposes, it was considered prime agricultural land. There was significant protest
against this project from local landowners who weren’t in favor of taking these prime farmlands
out of agricultural cultivation (Cultural Resources Unlimited, 1990).
2.5 VEGETATION DESIGN
Based on the series of soil, geological and hydrological conditions of the site, the 1991
Kachituli restoration project designers determined that the oxbow would be an optimal feature
for the site; These assessments determined that the water table was accessible enough to support
healthy wetland and riparian plant communities. Specifically, the plans called for the
establishment of riparian plantings including: an Oak woodland (Quercus lobata), an Elderberry
(Sambucus nigra) savannah, a Cottonwood forest (Populus Fremontii), a Willow thicket, and
wetland plants (Hey and Phillipi, 1999). The complete breakdown of all of the species (Figure 1)
corresponds to each of these vegetation communities.
Table 1: Vegetation Community Design (Green and Kelly, 1990; Mcguirk, 2014)
10
3.0 METHODS
3.1 CALIFORNIA RAPID ASSESSMENT METHOD
The California Rapid Assessment Method (CRAM) was used to assess the landscape,
hydrologic, physical and biotic condition of the site. The CRAM is part of a broader assessment
method, known as the national Wetland and Riparian Area Monitoring Program (WRAMP) and
is used to characterize the performance of wetlands across the nation. These types of assessments
are tools that aid in the monitoring of regulatory programs, including mitigation requirements
initiated as per the Porter-Cologne Water Quality Control Act as well as the US Clean Water act
sections 404 and 401 (CWMW, 2010). As a wetland status evaluation tool, the WRAMP model
breaks down this assessment process into three distinct categories (Table 1) (CWMW, 2013).
In documenting the adaptation of the larger Rapid Assessment Method (RAM) for
implementation in California, Sutula et al. (2006) indicates that the CRAM incorporates
methodologies from several other states including the Washington state Wetland Rating System,
the Ohio Rapid Assessment Method (ORAM), as well as RAMs from Montana and
Pennsylvania. So that the CRAM can be utilized on a statewide monitoring basis, developers of
the CRAM also draw from some of the conceptual assessment approaches enacted by the CA
Fish and Wildlife Service as well as from the methods of the State Water Resources Control
Board. Several additional interagency collaborations have taken place in selecting the biological
metrics specific to California’s wetland demographic, like for example, the inclusion of seasonal
depressions or vernal pool metrics that may not have otherwise been captured in the metrics
specified in the assessments of other states (Sutula et al, 2006).
11
Table 2: Components of the WRAMP Model
Level 1
Level 2
Level 3
Map- bases inventories and landscape profiles (CAR)
Rapid Assessment of overall condition (CRAM)
Intensive assessment of selected aspects of condition, stress, or function
(CWRCB, 2011)
Thus, the CRAM falls within the level 2 category (CWRCB, 2011). According to the
State Water Resources Control Board (2011), the CRAM can be characterized as an “expert
diagnostic tool…requiring expertise comparable to jurisdictional delineation.” Thereby, this
assessment method relies heavily on professional judgment in the field. Each of the three model
components (level 1, 2, and 3) of these assessments are used in generating condition summaries
which are presented to resource agencies at the state-level (Stein et al, 2009).
One of the goals of these rapid assessment methods is to characterize the health and
ecological condition of a site as a management tool. Because addressing ecological site
conditions require complex training, scientific understanding, ecologically sensitive protocols
and management participation, CRAM has been utilized as a cost-effective and timely approach
to such an, often, underfunded process. Stein et al. (2009, p. 248) confers that “the resultant state
[of a particular wetland] can be evaluated based on a core set of visible field metrics.” In this
way, the CRAM relies on “observable field indicators as surrogates for direct measures of
condition” (Stein et al, 2009, p. 247). Notwithstanding, independent level 3 quantitative data is
collected to validate evaluations that have been determined utilizing level 2 methods such as the
CRAM.
12
Specific to level 2 data, the CRAM utilizes four attribute categories used to assess
ecological conditions: 1) landscape context, 2) hydrology, 3) physical structure and 4) biotic
structure (Stein et al, 2009). The actual scoring for CRAM is generated from the scaled
computation of each of the four attributes: buffer and landscape context, hydrology, physical
structure and biotic structure (figure 2). Within each of these four attributes, there are sub-
metrics that are assigned according to
how closely the site condition is
associated with the “A, B, C or D”
rating. In this rating rubric, “A” equals
the highest score of 12 and “D” equals
the lowest score of 3 etc. This scoring
method totals each value within each
attribute into a raw score and then a final
attribute score. Finally, from all of these
respective scores, an overall AA score is
computed form the average of each of
these attributes (CWMW, 2013).
Prior to the Kachituli site visit, the GPS location was established and a map was
generated to define the boundary of the assessment area, the AA). Using the map, the buffer area
was also generated according to a 500m-study area determined from the north, south, east and
west directions from the AA (CWMW, 2013).
Then, at the Kachituli site, the CRAM was utilized first in the spring, May 3, 2014 to
determine the conditions in the depressional wetland, and then again in the late summer, August
Figure 2: CRAM Attributes and Metrics (CWMW, 2008)
13
18, 2014. Both samplings have taken place during one of the most extreme drought years
experienced in Northern California. Summer of 2014 was the first time in 20 years that the
oxbow has gone dry (D. Kelley, K&AES, Inc., personal communication). During both
assessments, the CRAM field sheet was tallied on site; whereas, the overall AA score was
computed afterward off-site. Likewise, plant specimens that could not be identified on site were
collected and eventually keyed out off-site using the Jepson Manual. Plant specimens that could
not be identified to species were categorized as unknown but were identified to their genus.
4.0 RESULTS
4.1 SOIL SURVEY 2014
Although pre-project soils classified the Kachituli site as consisting mainly of Sycamore
Silty Clay Loam, Sycamore Drained, Sacramento Clay, Sacramento Drained and Valdez soils
(Kelley and Green, 1990; Hey and Philippi, 1999). Prior to restoration on site, the Sycamore
Silty and Sycamore Drained soils were found on the top layer throughout the area (Kelley and
Green, 1990), but because the topmost layers of these soils were excavated from the Oxbow area
and then piled onto the adjacent upland area nearest the entrance of the site, the soil profiles
were, thereby, disturbed. Even given this disturbance caused over 20 years ago, it unlikely that
soils beneath the surface would have changed given that these alluvial soils may have
accumulated and developed on the project site over a span of several thousands of years. (A.,
Margenot, UC Davis, personal comm).
However, since no soil cores or reclassification had been done on Kachituli post-project
implementation (D, Kelley, Kelley and Associates, personal comm.), soil cores were taken at the
site to 1) explore this relationship between the soil profiles mapped pre-project and the profiles
of 2014 and 2) estimate potential for carbon sequestration at the sight.
14
Figure 3: Kachituli 2014 Soil Profile
(Margenot, 2014)
The soil profile was surveyed at the eastern most edge of the Oxbow at the slope of the
upland area (figure 3). Because the soils beneath the topmost layer were exposed to natural
weathering during the excavation, these soils were compacted by the weight of the machinery
used to remove the souls. Thereby these soils were more likely to have a decreased level of plant
activity in the roots (Ballantin eet al, 2011). In this way, the removal of the cabon-rich topsoil
that was placed on the perimeter of the oxbow allowed for more Soil organic carbon (SOM) to
accumulate on this area, which was sampled (A. Margenot, U.C. Davis, personal comm.). This
restoration process which compacts the soil was expected to slow the ability for nutrient cycling,
but these processes are generally considered to continue years later after the initial restoration
(Ballantine et al, 2011).
15
This helps to explain why the 2014 soil profile showed evidence of more organic carbon
in the A horizon of the soil , and this SOM was much farther down in depth than was expected
of the soils mapped prior to restoration sampled. Thereby because these soils were affected by
human-caused process of restoration, these layers were less able to develop and so the carbon
layer is more significant. Thereby, the redoximorphic features that you would usually find in the
initial breakdown of the soils mapped, were more isolated in the soil profile found in 2014 (A.
Margenot, U.C. Davis, personal comm). The success of this restoration site is evidenced by the
succession of plant communities supported by the reconstructed Oxbow decades after the initial
restoration (McGuirk, 2014). The healthy, carbon-rich soils may have provided increased
nutrient support to the habitat patches. Further exploration and analysis of the carbon storage
capacity in wetland soils such as these top layers with high SOM may add to the growing
discussion of wetland restoration to contribute to carbon sequestration (DOI, 2011).
4.2 FALL 2014 CRAM
The attribute scores of the McGuirk et al (2014) CRAM completed at the Kachituli
Oxbow during the spring of 2014 captured the scores of attributes1, 2, 3, and 4 as 56, 100, 75,
and 66 percent respectively (Table 2). Thus the final overall AA score for the site was 74%.
McGuirk et al (2014) indicated that this 74% was “well above average” given the range of other
CRAM scores administered throughout other restoration sites within the Bay/Delta region of
California. Furthermore, McGuirk (2014) found that most of the overall CRAM scores assigned
to project sites in the region fell between 55% and 85% while none received overall scores of
higher than a 95%. Thus, the overall score of 75% characterizes the site’s ecological condition as
“good” in that it is sustaining habitats for a variety of plant and animal communities, compared
to other sites in the Bay/Delta region, especially given that it receives no outside irrigation.
16
Specific to the individual attribute metrics, there were eight patch types for the sub-metric of
“structural patch richness” and that there were four plant community layers and 10 co-dominants
that were identified for the “plant community” sub-metrics (McGuirk, 2014). The calculation and
computation data for this assessment are attached (Table 1). Likewise, the complete California
Wetlands Monitoring Workgroup guide to the scoring method for each of these attributes is also
provided (See Appendix).
4.3 SUMMER 2014 CRAM
The results of the summer 2014 CRAM attained the following scores for attributes 1,2, 3
and 4: 68, 100, 62.5 and 67 percent respectively (Table 2). The scoring of these calculations were
performed with regard to the same protocols as the Fall 2014 CRAM. The overall average of the
above scores of the AA for this CRAM was 74.37%. Because this overall score was the same as
the previous CRAM scores for the spring, the assessment from McGuirk (2014) was supported in
these results.
The CRAM index considers scores between 63-81 as “good” while scores between 82-
100 are considered to be sites whose ecological condition or overall health is “excellent”
(SWRCB, 2014). Thereby, the overall ecological condition assessed during the summer of 2014
was characterized as “good,” as is indicated by relatively high average of each of the metrics
observed on site, especially given that the site receives no outside irrigation and relies
completely on its below –ground surface connection and precipitation. Even given this
hydrologic condition, observations supported evidence of several structural patches which show
the potential for a variety of plant and animal communities.
17
Table 3: Scoring Sheet sorted by Attribute and Sub-metric for both Spring 2014 and Summer 2014
Attribute & Sub-metrics
A=12; B=9; C=6; D=3
Spring 2014 CRAM
(McGuirk, 2014)
Summer 2014 CRAM
BUFFER AND LANDSCAPE
Aquatic Area Abundance 3 6
Percent of AA With Buffer 12 12
Average Buffer Width 12 12
Buffer Condition 9 9
TOTAL SCORE 13.39/24*100=56% 16.39/24*100=68%
HYDROLOGY
Water Source 12 12
Hydro-period 12 12
Hydrologic Connectivity 12 12
TOTAL SCORE 36/36*100=100% 36/36*100=100%
PHYSICAL STRUCTURE
Structural Patch Richness 9 6
Topographic Complexity 9 9
TOTAL SCORE 18/24*100=75% 15/24*100=62.5%
BIOTIC STRUCTURE (Plant Community Composition = A-C)
A: Number of Plant Layers 12 12
B: Number of Co-dominant Species
12 12
C: Percent Invasion 3 3
Plant Community Composition Metric ( Average of A-C)
9 9
Horizontal Interspersion
9 9
Vertical Biotic Structure
9 6
TOTAL SCORE 24/36*100= 66.7% 24/36*100=66.7%
OVERALL SCORE 74% 74%
18
5.0 DISCUSSION
The results from the spring 2014 CRAM and the summer 2014 CRAM indicated that
overall scores remained the same: 74%. Thus, the overall CRAM scores did not measure sizeable
changes within Kachituli’s site conditions from the growing season compared to its dry season.
In exploration of these results, three possible explanations arose as the most likely:
1.) the CRAM scores did not reflect a change because there truly were no changes
evident in the site conditions between the growing season and the driest season.
2.) the CRAM scores did not reflect a change because although there were seasonal
changes at the site, these changes were not sizeable enough to warrant changes in CRAM scores.
3.) the CRAM scores did not reflect changes because the CRAM was not an evaluation
tool sensitive enough to detect such inter-seasonal changes even in an extreme drought year.
ATTRIBUTE 1:Landscape and Buffer
Because the structure of the overall AA score is generated from averaging the scores of
the attributes (CWMW, 2009), the scoring of the individual attributes of buffer/landscape
context, hydrology, physical structure and biotic structure was assessed to determine whether
their sub-metrics had also remained the same.
Our data revealed an inconsistency within the results of buffer and land context attribute
that may have derived from sampling error, thus detracting from the anticipated effect of a
decreased the physical structure attribute. Specifically, the AA scored higher during the summer
season (“C”) versus the spring (“D”). This AA metric measures “the percentage of the transect
that passes through an aquatic feature of any kind” (CWRCB, 2011). Because the depressional
area of Kachituli has not had any new stressor identified in the checklist, it was safe to interpret
that the site area had not lost or gained acreage, but rather, the boundary of the AA had changed
19
during the second CRAM; this was verified by the differing aerial photographs generated for
each separate CRAM in spring and in the summer.
Thereby, the changes measured in this attribute seem to have been due to varying
sampling regions within the depressional wetland site, since the transect lines had been
established at different locations during both sampling opportunities in the spring versus the
summer. The procedures for delineating the AA require mapping prior to sampling at the site so
that once in the field, they can be refined. Upon comparison to the data from spring 2014, it then
appeared that 1) the transect lines were drawn from separate starting locations and 2) project
boundaries were established differently. Specific to the spring 2014 CRAM, the adjacent Army
Corps site was noted as “south of site 0-15m.”
Thus, it seems possible that the spring 2014 data may have considered the Corp site to be
outside of the AA. This may have been what generated a key distinction in the scores for the AA.
If we were to assume that this was true and adjust the first metric of attribute one to retrofit the
boundary of the AA in the summer 2014 CRAM to align with that of the spring, then the overall
score for Summer 2014 would change form 74 % to 71%. Although this three percent reduction
would still result in the overall characterization of the site’s ecological condition as “good”
relative to others in the region, this reduction would leave more room to interpret that either the
intra-seasonal changes observed at Kachituli were sizeable enough to warrant a change in the
CRAM score or that CRAM is a tool sensitive enough to detect seasonal changes.
However, because one of the goals of this study was also to “assess the applicability of
the CRAM as a tool,” one observation is that the application of the tool may not be standardized
well enough for teams to be able to replicate the sampling procedures in the same location. This
may indicate that both increased level of expertise and practice is needed to carry out the CRAM
20
(Stein et al, 2009; Klimas, 2006), as well as the need for more clarification in the user’s manual
regarding the assessment of both the larger AA area and the project area. Therefore, if both
samples were able to continue with this assumption that multiple boundaries could have been
established for this attribute at different sampling areas, and both could result in varying attribute
scores, then it is possible that the methodology for this attribute may require more refinement.
Furthermore, editing the AA boundary post-sampling would bias the second sampling by
attempting to match the prior season, and the goal of this study was to examine the results of
summer 2014 independently of the results of the fall 2014 so that a comparison could be made
after both samples had been completed, thereby introducing the least amount of bias as possible.
In light of the potential for inconsistency, boundary establishment can be refined in future
research to rectify these results. Fennessey et al. (2004) reviewed a sample of rapid assessment
methods utilized across the nation, having noted that defining the AA is critical because of how
it sets the foundation for how the data is collected. Establishing the AA requires consistency in
mapping and sample design (Fennessey et al, 2004). If sampling error was not the explanation
for this result, the second and third explanation might still have been likely.
ATTRIBUTE 2: Hydrology
The results indicated that the hydrology attribute and each of the sub-metrics of water-
source, hydro-period and hydrologic connectivity were indeed the same from spring to late
summer, which supports rationale number one that there had not been observable changes to
Kachituli’s water source. This is consistent with the methodology that assigns an “A” (12 points)
to depressional wetlands whose water source is from natural processes like groundwater and
precipitation (CWMW, 2013). Given that water sources are often characterized prior to site visits
based on background research on the site, the hydrology was expected to remain the same even
21
though it was possible that the hydrologic connectivity underground could have changed.
However, to the extent of our visual observations, there were no indications during sampling that
the oxbow was not receiving water diversions to sustain the pond nor was runoff from storm
drains or irrigation detected on-site.
Correspondingly, these water source metrics are key in assessing the capability of the
area to sustain both plant and animal habitats, especially during dry seasons (CWMW, 2013).
Based on these observations, this was the only attribute that received both an overall score of
100% and the same scores for its sub-metrics for both the spring and summer. This is consistent
with the results of the Stein et al. (2009) CRAM validation study which determined that
compared to the other three attributes, the hydrology attribute had the lowest percent error rates
between teams of practitioners who assign scores.
However, what did remain uncertain in the context of determining seasonal variation
during this drought year was the sub-metric of hydroperiod. The CRAM manual rating for this
sub-metric states that depressional wetlands receive an “A” when the “hydroperiod of the AA is
characterized by mostly natural patterns of filling or inundation and drying or drawdown”
(CWMW, 2013, p. 19). Because evidence of “stress and mortality of hydrophytes” and
“encroachment of terrestrial vegetation” was observed, we were able to characterize that
Kachituli was experiencing a reduced duration of its hydroperiod and thereby assign an “A”
score. What was unclear, however, was whether this drawdown fit into the natural drawdown
patterns of the site was significantly induced by severe drought conditions. The hydro-period
metric captures inundation during average or natural patterns (CWMW, 2013) but decreased
regional rainfall indicates that 2014 was not an average year. Therefore, both because no
previous CRAM data exists for this site, and because the severity of this current drought is
22
unprecedented, characterizing the variations within the sub-metric hydro-period during this
atypical period may skew the assessment in favor of “A” when conditions may suggest lower
scores when/if drought pressures result in variations that eventually become “natural.” This may
have direct restoration management implications, in that stakeholders have to be able to identify
which site conditions are changing because natural, expected patterns and therefore do not
require allocation of funding, and which site features are in need of more resource investment to
maintain optimal habitat communities. Thus, in order to account for seasonal variability more
clearly, perhaps parameters could be established within these assessments that specify how long
and by how much hydro-period patterns have to deviate from the “norm” in order to be of
concern.
ATTRIBUTE 3:Physical Structure
Based on germination, flowering and dormancy patterns among differing plant
communities such as annuals and perennials, we expected to observe changes within the physical
structure attribute (Mitsch & Gosselink, 2007). CRAM scores did, indeed, reflect changes within
the raw attribute score of this attribute. The first of these changes were measured within
the “structural patch richness” sub-metric. During the spring sampling period, nine patch types
were identified as follows: organic debris across depressional wetland, animal mounds/burrows,
parallel high water marks, algal mats, large woody debris, non-vegetated flats or bare ground,
open water, soil cracks, and standing snags (CWMW, 2013).
Whereas, in the summer, six patch types were identified: standing snags, animal mounds,
parallel water marks, large woody debris, bare ground and soil cracks (Ibid). Because data
gathered from this physical structure attribute is used to infer relationships between the
landforms and the wildlife that inhabits the area, these observable habitat patches are key
23
components of the CRAM (Sutula et al, 2006). For instance, the presence of animal mounds may
infer the existence of mammals that occupy Kachituli’s depressional wetland. Although not
directly listed as one of the “structural patch types, ” scat, possibly from a larger animal (i.e.
coyote or bear) were observed within the AA (figure 4). In this way, because direct sampling
of these animals is not performed with the CRAM, such observations serve as indicators from
which the potential capacity of the Kachituli to provide
habitat for a variety of animals can be inferred (Stein et
al , 2009).
The presence of standing snags can be a habitat
feature utilized by the endangered species Swainson’s
Hawk (Buteo swainsonii) (Green and Kelley, 1990). In
this way, this patch type sub-metric act as a surrogate
for habitat since the species itself is not directly
measured (Sutula, et al, 2006; Stein et al, 2009; Fennesey et al, 2004).
Although it was expected that we the CRAM would also measure changes within the sub-
metric of topographic complexity, the CRAM score did not capture variations from spring to
summer. Still, the seasonal changes measured by the CRAM in the “structural patch richness”
sub-metric were sizeable enough to reduce the overall score of this attribute. Specifically, these
changes resulted in a reduction in the score for that attribute by six points resulting in the
reduction in the final attribute score from 75% to 62.5 % or “C to D.” The physical structure
attribute represents expected capacity of the site to provide habitat for and support of various
plant, animal, bird and amphibian populations (SWRCB, 2014). Thereby, our observations
resulting in a decreased score in this attribute corresponds to an expected reduction in the
Figure 4: Inferred Habitat Use by Mammals through CRAM Metric-Positive effect on CRAM Score
24
capacity of the site to maintain a diversity of habitat features during the summer as compared
with the spring (SWRCB, 2014). This is consistent with what was observed in the spring
sampling: the oxbow was ponded (figure 4) which captured both open water and algal mats.
Whereas, during the summer sampling, the oxbow had gone dry and therefore the algal mats
were absent (figure 5). In a “normal year” the Oxbow would remain ponded and so open water
and algal mats could be expected to provide habitats or food sources for amphibians, migratory
birds as well as other obligate wetland species.
Figure 5: Kachituli Oxbow Fall 2014 (McGuirk, 2014)
25
Figure 6: Kachituli Oxbow Summer 2014 (Stevens, 2014)
Given this importance of habitat to restoration condition, it was anticipated that such a
decrease in this attribute’s score would have resulted in a decrease in the overall AA scores from
spring to summer. However, it seemed that because the scores of attribute one (buffer and
landscape context) also changed, there seemed to be a cancelling-out effect between these two
attributes, thereby nullifying individual effect upon the overall CRAM scores as a whole. This
phenomenon was also observed by a Corps regulatory review that suggested that because the
overall score is aggregated, it is often unclear which scores are actually changing within the
overall score (Klimas, 2008). Therefore, it may not have been that the decrease in patch types
26
was not sizeable enough to warrant a change but rather that other attribute fluxes masked this
attribute’s significance.
ATTRIBUTE 4: Biotic Structure
Attribute four, biotic structure, also received the same score in the summer as was issued
for the spring. However, when reviewing the sub-metric indicators, it becomes evident that
although the scores assigned were the same from season to season, the number of co-dominant
species observed did change from season to season, which was consistent with our ocular
estimates and photo records. This observation was, thereby, inconsistent with explanation
number one, that there really was no change. The presence of co-dominant species falls within
the plant community sub-metric of attribute 4 (CWMW, 2009). Specifically, during the spring,
10 species were identified, 4 of which were invasive; during the summer 12 species were
identified, 5 of which were invasive. Thus, the percent invasion increased from 40% in the spring
to 42% in the summer, specifically, a sizeable increase in the invasive weed horseweed, (Conyza
canadensis (figure 7). As is well documented, the presence of invasive species has been a critical
concern in adaptive management strategies (Moore et al, 2011; Golet et al., 2013). Perhaps, then,
if it was true that invasive species were indicators of stress on the site and that the summer site
did inventory more invasives than during the spring, it may have been that this 2% increase in
invasives was not sizeable enough to warrant a lower attribute score, which supported
explanation number two.
27
Figure 7: Presence of Invasive Species- Negative effect on CRAM Score
However, the results of the “biotic structure” attribute were not fully explained by
rationale number two. This inconsistency was shared in the Stein et al (2009) study that
correlated statewide CRAM scores with comparable, independent, intensive data, also referred to
as level three data. Specific to the “biotic structure” attribute, this study detected a twenty-five
percent margin of error within scores performed months apart from each other (Stein et al, 2009).
This study further suggested that “seasonal differences in plant communities may contribute to
variability in this attribute” (Stein et al, 2009, p. 258), which was the expectation of the summer
CRAM performed at Kachituli. Plants used in restoration of this Sacramento Valley region
typically exhibit characteristic responses to increased duration of sunlight, decreased amount of
precipitation, reduced access to shade and hotter temperatures (Moore et al, 2011). That the raw
attribute score for attribute four (biotic structure) remained the same even throughout the driest
28
season is an inconsistency that may have been supported by the third explanation. Perhaps there
were sizeable differences in the site condition that the CRAM was unable to detect. In this
interpretation, the CRAM is too course of a filter to detect inter-seasonal variation even in
extreme conditions (Stevens, 2014).
Another inconsistency within the data indicated that there were four species of willows in
the very tall layer in the summer but only 3 species of willows in the spring. This is inconsistent
with the characteristics of the “very tall” layer, in that it is more likely to observe a species
moving from the “short layer” to “medium layer” within a season, especially if the species is a
grass privy to more vigorous growth during its growing season. It is less likely, however, to
observe an absence of a species in the “very tall” layer from one season to the next. Or, perhaps
the particular species may have been considered plentiful enough to be considered a dominant in
the strata layer in one sampling and yet not in the next. Assuming that both sampling areas were
representative of the Oxbow, this would mean that this species would have had to suffer a loss so
significant that less than ten percent still remained. Because the stressor checklist surveyed
within the CRAM had not indicated that any drastic stressors occurred within the area, we
predict that this result may have been due to sampling error through the misidentification of
plants.
To recalibrate the inconsistency presented in this attribute, the co-dominant species and
percent invasion were recalculated both with all four willows and with three. The result was that
either way, the presence of + one species had no effect on the alpha- numeric score of sub-
metrics A or B. This is the case because the scores of “12” are assigned when there are at least 4
plant layers and when the number of co-dominant species is > 9. In both CRAM seasons, +
species maintained these thresholds. As for percent invasion (sub-metric C), in order to have
29
produced a variation in the score, the percentage would have had to be reduced by over 10 % to
be re-scored as a “C” instead of the “D” that was captured in both systems.
Still, as noted within the methodology, in order for the CRAM to be an effective indicator
of site conditions, it is optimally executed by professionals in the field (Sutula et al 2006;
Klimas, 2008). Nonetheless, as attested by Stein et al. (2009), misidentification of species is
common even within a broad spectrum of expertise levels, and so it is likely that the willow was
mis-identified, especially given that species of Willows are often identified when their catkins
are present, as was not the case during samplings. Moreover, because inconsistent plant
identification is recorded even in situations outside of academic training, expertise in wetland
identification has been noted as a substantial area for improvement in the validation phase (Stein
et al, 2009). However, Sutula et al (2006) suggested that there are tradeoffs to necessitating high
level of botanical expertise: the more skill that is needed to perform these assessments, the more
accurate your scores are likely to be. But this comes at the expense of time and money. Thereby,
with higher costs and sizably more time invested in assessments, the scope to which the CRAM
can be applied becomes smaller as well (Sutula et al, 2006).
Even accounting for these tradeoffs in expertise, studies suggest that CRAM scores have
been statistically reliable in relaying the overall condition of mitigation sites (Stein et al, 2009,
Sutula et al, 2006). Since measure to troubleshoot errors have been attempted, it seems that
although the scoring of the CRAM has many complex metrics where potential for errors can
manifest, it still seems that skills-set may have been less of a factor than rationales 2 and 3.
The Need for Qualitative Data Collection in Future Studies
As several authors suggest, these indicators, or metrics, relate to how ecosystems
function and therefore need to be validated using the components of the 1, 2 and 3, tier
30
framework (Stein et al, 2009; Sutula et al, 2006; CWMW, 2008; CWMW, 2011). In light of this,
Stein et al (2009) assert that these assessments have to be compared to independent results in
order to maintain credibility. This distinction affirms the need for the CRAM results of this
paper to be compared with an independent, consistent and repeatable method for qualitative
sampling in addition to the CRAM for each season. This is not to suggest that the implications of
a CRAM score poorly indicate a habitat's function, but rather that its scores should not be
performed as the single method in the field. Intensive L3 data collection like vegetation
sampling, bird surveying or benthic macro-invertebrate surveying is necessary validate the
assessment of the CRAM on a state-wide scale (Stein et al, 2009). Therefore to the CRAM's
credit, and therefore, legitimacy, this concern is emphatically addressed as an integral component
of the CRAM methodology, specifically within the "validation" process which attempts to rectify
these qualms between the CRAMs and independent sampling methods (CWMW, 2009; Fennessy
et al, 2004; Stein et al, 2009; CCWG, 2013). However, in agreement with many other studies,
Stein et al (2009) provide a caveat to this need for comparison to independent data, noting that
similar, direct-in-the- field data is often unavailable, especially for metrics like invertebrate or
avian populations where direct "collections" are far from optimal.
Specific to the extent of this study, collecting qualitative vegetation data within Kachituli
would be the preferred L3 intensive data needed for this site, especially since surveying for
Valley Elderberry Longhorn Beetle (Desmocerus californicus dimorphus) would have been
restricted to the riparian areas South of the Oxbow where the CRAM was performed. Vegetation
data was collected during this study, but was insufficient for the needs of this comparison. Since
qualitative data was not collected during the spring 2014 sampling but was collected during the
summer sampling, characterizations could be made from comparing the summer vegetative data
31
to the summer CRAM, but these comparisons could not be then taken together and compared to
the spring 2014 data to characterize seasonal variability because the goal of this study was to
characterize the inter-seasonal variability. Using the vegetative data to validate one season
without having vegetation data available to validate the other would not adequately address the
research goals of this study. Therefore in future studies, one approach in validating the results of
the CRAM as a tool for assessing this site would be to collect qualitative (L3) data for both
seasons of interest so that the changes in plant community composition and abundance in one
season can be directly compared to the other in the same way that the CRAM scores have
already been compared from one season to the other in this study. For example, the L3 data may
show how well the percent invasion metric within the biotic structure attribute (attribute 3)
assessed within the CRAM compares to the plant community composition sampling. Future
studies have the potential to shed light on several of the inconsistencies detected within the
CRAM as a tool for detecting the inter-seasonal variability of site conditions.
What was consistent within these CRAM scores was an observable metric within each of
the four attributes. This highlights the biotic-focused intent of scoring for each attribute within
the CRAM. Specifically, the hydrology attribute is scored according to its capacity to provide
habitat for animals and plants (Stein et al, 2009). As McGuirk et al (2014) concluded, the spring
2014 results of Kachituli’s CRAM score characterized it as successful, faring above average in
the hydrology and biotic attribute. Because our overall scores for the summer remained the same,
the conclusions of McGuirk et al (2014) can be inferred that the site conditions at Kachituli have
successfully maintained landscapes that support abundant habitats for flora and fauna. However,
further studies are needed to characterize the initial objectives of this study.
32
It is still unclear whether the site is still successful because seasonal changes were not
sizeable enough to reduce these scores or if the CRAM is not a tool sensitive enough to utilize
for this purpose. Consistent “average” scores from year to year are important for measuring
mitigation or restoration success since they serve as a tool for management and landowners to
characterize the continuing needs of a project (Stein et al, 2009). The expectation of this study
was that the CRAM assessment of this mitigation project’s ecological condition during a drought
year would result in a deviation from the “average” CRAM score. Because the scores did not
change overall, it is still unclear whether this consistency signifies that the drought has not
significantly and negatively impaired the Kachituli Oxbow or whether the CRAM is simply not
sensitive enough to detect the changes that may be occurring as the drought continues. Perhaps
with continued sampling and utilization of the CRAM at regular intervals, a better
characterization of the seasonal changes will be encountered.
33
References
Ballantine, K, Achnwider, R, Groffman, P, Lehmann, J. 2011. Soil Properties and Vegetative
Development in Four Restored Freshwater Depressional Wetlands. Soil Science Survey of
America. 76:1482-1495. doi 0.2136/sssaj2011.0362 (December 1, 2014).
California Water Resources Control Board (CWRCB). 2011. Introduction to California Rapid
Assessment Method for Wetlands and Riparian Areas
(CRAM). http://www.swrcb.ca.gov/academy/courses/cram/jun11/intro.pdf (November,
9, 2014).
California Wetlands Monitoring Workgroup (CWMW). 2013. California Rapid Assessment
Method (CRAM) for Wetlands and Riparian Areas, version 6.0 p. 95.
http://www.cramwetlands.org/sites/default/files/2012-04-05_CRAM_manual_6.0.pdf
(October 3, 2014)
California Wetlands Monitoring Workgroup (CWMW). 2008. California Rapid
Assessment Method for wetlands. http://www.cramwetlands.org/sites/default/files/2008-
01-24_CRAM%20Prospectus.pdf (October 25, 2014).
California Wetlands Monitoring Workgroup (CWMW). 2009. Using CRAM to assess
wetland projects as an element of regulatory and management programs: technical
bulletin. http://www.cramwetlands.org/sites/default/files/2009-
10_CRAM%20application%20tech%20bulletin_FINAL.pdf (October 3, 2014).
Carletti, A., De Leo, G., and Ferrari, I., 2004. A critical review of representative wetland rapid
assessment methods in North America. Aquatic Conservation: Marine and Freshwater
Ecosystems, 14,p. 103–113.
Central Coast Wetlands Group (CCWG). 2013. CIAP Task 3 summary report: verification of the
depressional CRAM wetland module.
http://ccwg.mlml.calstate.edu/sites/default/files/documents/finalreport-
depressionalCRAM.pdf (November 15, 2014).
Cultural Resources Unlimited, 1990. A cultural resources study. Lighthouse Marina
and Riverbend Development.
Department of the Interior (DOI). 2011. Challenges and opportunities for carbon sequestration in
the restoration of wetlands. University of Oregon,
http://www.doi.gov/restoration/upload/pm-1c-bridgham.pdf (December, 2, 2014)
Fennessy, S., Jacobs, D. and Kentula, M., 2004. Review of Rapid Methods for
Assessing Wetland Condition. EPA/620/R-04/009. U.S. Environmental Protection
Agency,Washington, D.C. http://www.epa.gov/nheerl/download_files/
publications/rapidmethodreview.pdf (October, 3, 2014).
34
Green, M., Kelley and Associates and Thasos Environmental Group. 1990. “A proposal
for the Lighthouse Marina Project, West Sacramento, California. Lighthouse Marina and
River Development.
Golet,B., Brown, D., Carlson, M., Gardali, T., Henderson, A., Holl, et al. 2013.
Successes, failures and suggested future directions for ecosystem restoration of the
middle Sacramento River, California. San Francisco Estuary and Watershed Science, v.
11(30), p. 1-31.
Hey, D. and Philippi, N. 1999. A Case for Wetland Restoration. John Wiley
and Sons, New York City, p. 63.
Jackson, L, Haden, V, Hollander, A., Lee, H., Lubell, M., Mehta, V., O’Geen, T., Niles, M.,
Perlman, J., Purkey, D., Salas, W., Sumner, D., Tomuta, M., Dempsey, M., and Wheeler,
S., 2012. Adaptation Strategies for Agricultural Sustainability in Yolo County,
California. California Energy Commission.
http://www.energy.ca.gov/2012publications/CEC-500-2012-032/CEC-500-2012-032.pdf
(December 9, 2014).
Kelley, D. and Green, M.. 1990. “Soils of the Kachituli Wetland, Yolo County, California,”
Lighthouse Marina and Riverbend Development.
Kelley, D., (n.d). Personal Communication . L., Morris, Interviewer. 2014. Sacramento, CA.
Klimas, C., 2008. Comments on the California Rapid Assessment Method for wetlands, U.S.
Army Engineer Research and Development Center. p 2-10.
http://www.cramwetlands.org/sites/default/files/CRAM%20review%20Klimas.pd f
(October 3, 2014).
Margenot, A. (n.d).Personal communication . L. Morris, Interviewer. 2014. U.C. Davis,
Department of Land and Air Research Program, Davis, CA.
Miriam Green Associates and Kelley and Associates. 1990. Kachituli Oxbow
revegetation plan; a proposal for off-site mitigation for the Lighthouse Marina Project,
West Sacramento, California. Lighthouse Marina and Riverbend Development,
Sacramento, CA, p. 32.
Mitsch, W. and Gosselink, J..2007. Wetlands: Fourth Edition. John Wiley & Sons, Inc.,
Hobocken, NJ, p.
Moore, P., Holl, K.,Wood, D. 2011. Strategies for Restoring Native Riparian Understory Plants
Along the Sacramento River: Timing, Shade, Non-native control and Planting
Method. San Francisco Estuary and Watershed Science.,v. 9(2), p 1-15.
35
Parker, T., Callaway, J., Schile, L., Vasey, M., Herbert, E.. 2011. “Climate change and San
Francisco Bay-Delta tidal wetlands”, San Francisco Esturary and Watershed Science, v.
9(3), p. 1-17.
Stevens, M. 2004. Ethonoecology of selected California wetland plants. Fremontia.32(4), p.7-15.
State Water Resources Control Board (SWRCB, 2014). California Rapid Assessment Method for
Wetlands and Riparian Areas Meaning of CRAM Scores Example Applications and
Interpretations. http://www.waterboards.ca.gov/academy/courses/cram/jun11/apps.pdf
(December 9, 2014).
Stein, D., Fetscher, E., Clark, P., Wiskind, A., Grenier, L., Sutula, M., and Grosso, C. 2009.
Validation of a wetland rapid assessment method: use of EPA’s level 1-2-3 framework
for method testing and refinement. Wetlands, v. 29(2), p. 648-665.
U.S Climate Data (USCD), 2014. Weather history Woodland by month and year.
http://www.usclimatedata.com/climate/woodland/california/unitedstates/usca1260/2011/1
2 (December 9, 2014).
Sutula, A., Stein, E., Collins, J., Fetscher, E., Clark, R.. 2006. A practical guide for the
development of a wetland assessment method: the California experience. Journal of the
American Water Resources Association. 4215 (2), p. 157-175.
Zedler, J., Dohetry, J., Miller, N., 2012. Shifting restoration policies to accept
landscape change, novel ecosystems, and monitoring. Ecology and Society, v. 17(4), p. 1-
16.