Rubus armeniacus (Himalayan Blackberry) tolerance and vigor response to photic
and edaphic Conditions in western Oregon
Joshua S. Caplan
jcaplan@pdx.edu
Major advisor: J. Alan Yeakley

Rubus armeniacus (Himalayan blackberry, R. discolor, R. procerus) is an aggressive plant invader of disturbed habitats in the Pacific Northwest. At 41 sites dominated by R. armeniacus, we measured patch height and mean floricane length, as well as canopy cover, slope, aspect, and soil properties (color, texture, organic matter, pH, and NO3+NO2-N). For several soil properties we compared our data to National Resource Conservation Service soil survey data for the soils in the vicinity of our sites. Edaphic conditions in which Himalayan blackberry appeared were more acidic (0.6 pH units, p < 0.001), contained more organic matter (5.3%, p < 0.001) and sand (25.6%, p < 0.001), but contained less silt (9.4%, p = 0.03) and clay (13.4%, p < 0.001) than did the surrounding areas. Ln-patch height was significantly explained by canopy cover (R2 = 0.44, p < 0.001) and floricane length was significantly explained by gravel (R2 = 0.11, p = 0.03). Our data suggest that shade is the primary environmental determinant of R. armeniacus' appearance and vigor. Our results further suggest that R. armeniacus is tolerant of a wide range of soil conditions (notably coarse texture), and that its vigor can be affected at edaphic extremes. An ability to withstand relatively infertile soils with only a small reduction in vigor may explain R. armeniacus' appearance on more coarse-textured substrates than are typical for western Oregon soils. In combination with its preference for high light availability, this factor may help explain the frequent appearance of R. armeniacus in anthropogenically disturbed habitats.

Stream Nutrient Criteria and Trophic Classification for the Northwestern Cascades in Oregon
Miguel A. Estrada
psu22135@pdx.edu
Major advisor: Yangdong Pan

Excessive nutrient input is one of the top environmental stressors to streams and rivers. One important tool for resource management is the development of a nutrient loading criteria and a trophic classification of streams. The hypotheses for this study are 1) that benthic algae, as integrators of temporal changes of stream conditions, can best reflect stream trophic conditions from the vantage point of species composition as nutrient concentrations changes, and 2) that a combination of stream nutrient, benthic algae productivity and watershed characteristics analysis can yield a robust method for trophic based stream classification and stream nutrient criteria goals. To test these hypotheses 18 streams located in the Northwestern Oregon Cascades were selected and sampled monthly from September 2001 to September 2002. These included streams with watersheds with 90% or more of forest cover, to streams with a variety of land uses in their watershed. The preliminary results indicate that the selected watershed can fulfill the land use gradient requirements, and also offer some insights on the seasonal variations of water quality related to land use. When samples are separated by season (rainy season versus dry season) the results have shown that during the rainy season turbidity and nutrients are related to overall watershed land use gradients. Answering the hypotheses of this research will increase the understanding of the complex relationship between benthic algae and stream nutrients under the context of a trophic stream classification objective. This research also has the potential to promote methods useful for the resource manager.

Effect of riparian vegetation on heavy metal concentrations in an urban stream.
Rebecca Gloss
gloss@pdx.edu
Major Professor: Alan Yeakley

Riparian vegetation buffers have been shown to reduce excess runoff of nutrients and sediments to streams (USEPA 1988, Line et al. 2002), but their function in preventing metal loading is poorly understood. We hypothesized that by reducing surface runoff, increasing the amount of organic matter with which metals can bind, and taking up metals directly, riparian zones may reduce the input of dissolved metals to streams. We installed shallow groundwater wells at 6 sites along Johnson Creek: 3 lined with less than 40m of vegetation and 3 with vegetation buffers at least 200m wide. From September until May, we collected weekly samples of the shallow groundwater and surface water at each site, and analyzed 7 weeks of those samples for zinc, copper, and lead concentrations by inductively-coupled plasma mass spectrometry (ICP-MS). We predicted that surface water dissolved metal concentrations would show a cumulative effect from the entire watershed, and would increase from upstream to downstream. We also predicted that concentrations in shallow groundwater would be representative of adjacent, small-scale land use (Sonoda et al. 2002), and would increase with decreasing adjacent riparian buffer width. Results show that metal concentrations at buffered and unbuffered sites were not significantly different for Zn, Cu, and Pb. Shallow groundwater concentrations of the metals, however, were significantly higher than surface water concentrations (p<0.001).

We conclude that the most important factors affecting metal concentrations were streamflow and subsurface adsorption/desorption processes, and that local riparian buffer conditions did not exert significant control over local stream water metal concentrations.

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Potential colonization of the Pacific Northwest by the mitten crab (Eriocheir spp.)
Erik Hanson
ehanson@pdx.edu
Major Professor: Mark Sytsma

The catadromous mitten crab (Eriocheir sinensis) is an invasive species with the potential to invade the Pacific Northwest and impact native species and habitat. Native to Asia, the mitten crab has caused severe impacts in Europe and California and has the potential to impact salmon through predation on salmon eggs and redd disturbance. Through the analysis of habitat and environmental conditions in the crabs native and introduced range, an examination of life history traits, and development of a larval recruitment model, at risk estuary-river systems can be identified for monitoring and management.
Initial results suggest that the estuarine larval stage limits population establishment and recruitment. The zoea require high salinities, moderate temperatures and an extended development time prior to returning to freshwater to mature.
Larval estuarine development is complicated by the potential for larval vertical migration, a behavioral mechanism by which larvae may remain in the estuary or return from coastal waters in later stages by moving in and out of tidal and salinity currents. Zoea migrate in response to light and tidal cycles or salinity currents. Ongoing experiments test the response of zoea stages to light cycles and salinity layers in 2m vertical tanks. The position of the larvae is recorded over a 48-hour period with an automated video system and analyzed. The data from these experiments will be utilized in estuary circulation models to predict where and under what conditions are mitten crabs likely to become established in the Pacific Northwest

Stormflow dynamics of dissolved organic carbon and total dissolved nitrogen in a small urban watershed.
Aaron Hook
hook@pdx.edu
Major Professor: Alan Yeakley

We examined patterns of dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) loading to a small urban stream during baseflow and stormflow. We hypothesized that during storm events in an urban watershed, contributions from impervious surfaces dilute the riparian contribution, resulting in lower concentrations of DOC and TDN during stormflows than during baseflow. We tested these hypotheses in a small urban watershed in Portland, Oregon, over a three month period during spring, 2003. We compared baseflow and stormflow chemistry using Mann Whitney tests (significant at p<0.05). We also applied a mass balance to the stream to compare the relative significance of impervious surface contribution versus natural hydrologic flowpaths (i.e., riparian) contribution.

Results showed a significant increase in stream DOC concentrations during stormflows (median baseflow DOC = 2.00 mg L-1, median stormflow DOC = 3.46 mg L-1). TDN streamwater concentrations, however, significantly decreased with stormflow (median baseflow TDN = 0.75 mg L-1, median stormflow TDN = 0.56 mg L-1). During storms, riparian areas contributed 70-74% of DOC export and 38-55% of TDN export to the stream, and impervious areas contributed the remainder. The observed pattern of increased DOC concentrations during stormflows in this urban watershed was similar to patterns found in previous studies of forested watersheds. Results for TDN indicated that there were very high baseflow nitrogen concentrations in the lower watershed in the lower watershed and that loading from impervious surfaces partially masked the riparian signal during stormflows. These results suggest the importance of preserving near-stream riparian areas in cities to maintain ecological processes in urban streams.

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Invasive Cordgrasses - Fragment Dispersal and Viability
Vanessa Howard
vhoward@pdx.edu
Major Professor: Mark Sytsma

Mechanical control methods on Spartina spp. involve disturbance to rhizomes and roots. We examined the viability of rhizome fragments and their potential role in dispersal.
Production of rhizome fragments by rototilling was studied in Willapa Bay, Washington. The top 10 cm of the sediment contained an average of 310 fragments/meter2. Each fragment was measured to find number of attached shoots, rhizome length & diameter. Survivorship of S. alternaflora rhizome fragments from California & Washington populations was investigated using a three-way factorial design. Two fragment sizes, approximating the those found in the Willapa Bay, were immersed in freshwater, 15 ppt or 35 ppt saltwater for 3, 8 or 15 days. Fragments were then individually planted and grown in greenhouse. Rhizome survivorship was low (< 8.6%) in all 35 ppt treatments. Survivorship ranged from 37.3 to 87.5% in freshwater and 15 ppt treatments. Large rhizomes appeared to have higher survivorship than small rhizomes at all salinities. The immersion duration appeared to have little to no effect on survivorship.

Low survival in high salinity water, even for short periods, suggests that fragments have a low probability of surviving ocean dispersal between estuaries. Higher survival at lower salinities suggests dispersal within an estuary may be more likely for fragments. Rototilling to control Spartina may spread the infestation within an estuary but is unlikely to result in spread to other estuaries. Tilling should be used with caution in estuaries with small, isolated populations of Spartina.

Effects of managed flooding on an invasive plant species in shoreline vegetation communities in a
Pacific Northwest wildlife preserve
Noah Jenkins
noahj@pdx.edu
Major Professor: Alan Yeakley

Water level management efforts in the Smith and Bybee Lakes Wildlife Area (SBL), an 800 ha preserve in the Columbia Slough area of North Portland, Oregon, include using a newly-established water control structure to suppress invasive reed canarygrass (Phalaris arundinacea L.) by flooding during spring and early summer growth periods. We sought to determine: (a) the present extent and distribution of reed canarygrass at SBL, particularly on lands that will be affected by the change in water regime; (b) the effectiveness of the change in water level at suppressing reed canarygrass; and c) the effects of the change in water level on other plant species distributions

Prior to seasonal flooding during the dry season in autumn 2003, we established 30 vegetation transects at SBL. These transects were distributed randomly throughout SBL, placed perpendicularly to the shorelines of the wetlands. Measurement of vegetation was conducted using the line intercept method at 10 cm intervals. Our baseline measurements showed that reed canarygrass averaged 49% cover in the shoreline areas of SBL. This invasive plant had a strong impact on plant diversity; nonparametric statistical correlation of reed canarygrass cover with Shannon diversity yielded a Spearman's rho value of - 0.77 (P<0.05). Subsequent measurements of these transects during 2004 will allow us to determine the effect of flooding on reed canarygrass growth and extent. Measurements of reed canarygrass stands during the 2004 growing season indicate a reduction in mid-season growth and alteration of growth habit for inundated patches as compared to upland stands.

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Oregon Business Decisions for Environmental Performance
U.S. EPA funded project, 2003-2006
Portland State University, University of Illinois, and Oregon State University
Cody Jones
jonesc@pdx.edu
Major Professor: Dr. David E. Ervin, Principal Investigator, Professor of Environmental Studies and Coordinator of Academic Sustainability Programs

Few analyses of corporate environmental behavior have measured environmental performance due to data difficulties. Most studies examine organizations' motivations to implement certain practices or participate in voluntary programs, either of which may not deliver performance. The proposed research will address this gap in knowledge and policy with primary data on performance collected from Oregon for-profit businesses.
The research is guided by three objectives: (1) Examine business environmental practices and firms' motivations for their implementation; (2) Examine the performance impact of these practices, and; (3) Determine features of voluntary programs that contribute directly and indirectly to improved environmental performance.

The investigators will use an econometric model to test influences of organization, industry, regulatory, and voluntary program factors on environmental practice decisions, and multiple elements of environmental performance. The model permits the simultaneous analysis of factors influencing implementation of individual practices and performance elements, and corrects for self-selection bias. Primary data from a random sample of approximately 2000 Oregon for-profit organizations will be collected. This data will describe practices, regulatory constraints, program participation, and environmental performance. Sector-specific reports will be given to respondents to help achieve the desired response rate. A panel of experts will advise the researchers on the sample, survey, and analysis.

Project findings will provide statistically sound, comprehensive evidence on the factors that are shaping voluntary corporate environmental behavior and performance in Oregon, and identify organization, industry, and regulatory factors likely to result in effective practices. Findings will inform the design of public and private voluntary programs to foster effective outcomes.

Waldo Lake Limnology
Laura Johnson
ljohnso@pdx.edu
Major Professor: Dr. Mark Sytsma

I am researching the physical and ecological properties of Waldo Lake. Waldo Lake is an ultra-oligotrophic lake located in the Cascade Mountains. My area of research focuses on monitoring the temperature at various depths in the water column and at different locations around the lake. This data collection will be important in determining the turnover time, heat budget of the lake, lake thermal stability and capture mid-season mixing events which may influence plankton abundance, community structure and primary productivity. Temperature data collected will be ultimately used, by others at PSU, in the development and calibration of a hydrodynamic model of the lake. Additionally, I have been involved in studying the ecology of plankton of the lake. This includes analysis of unpublished data from 1998-2003 using univariate and multivariate statistics and studying the diel vertical migration of plankton in response to changing light levels and mixing events over a 24-hour time period.

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Investigating Low Impact Alternatives for Control of Phalaris arundinacea (Reed Canarygrass) in Wetlands
Marshall Johnson
Mar723@yahoo.com
Major Professor: Dr. Joseph Maser

Management of invasive vegetation is one of the main challenges to natural resource managers whose goal is to preserve the biodiversity and functional values of wetlands. Phalaris arundinacea (reed canarygrass) is one invasive species that tends to dominate native vegetation, often resulting in a monoculture that is detrimental to many of the valuable resources provided by wetlands. Unfortunately, the common effective control techniques, such as herbicide application and removal of topsoil, often involve significant negative impact to wetlands. This study investigated the effectiveness of three alternative control techniques which would reduce incidental impacts. Techniques were chosen which would be reasonably affordable and available for the management of smaller urban wetlands, not necessarily applicable to large tracts of land. Two commercial solutions of vinegar and other natural substances were applied as "natural herbicides." The effectiveness of solarization with sheets of black plastic and wood chip mulch was also investigated. Treatments were applied to plots of homogenous P. arundinacea in two restored wetlands owned by The Wetlands Conservancy, in northwest Oregon. The results suggested that solarization with black plastic was the most effective technique, with a 100% reduction in the number of grass stems at the conclusion of the study. Woodchip mulch successfully reduced the number of stems by about 85%, however it appeared that the grass would eventually grow through the mulch and reclaim the area. The vinegar solutions were not found to significantly reduce P. arundinacea, but further investigation into the effectiveness of such products seems warranted.

Hydrologic Analysis of Waldo Lake Watershed
Adam M. Kennedy

Methods are presented for calculating monthly climate and stream flow conditions for this high elevation forested watershed located in the central Cascade Mountains. Mean monthly values are interpolated and extrapolated from nearby climate and stream gage stations in the vicinity of the Waldo Lake basin for the following variables: maximum and minimum air temperature, dew point, precipitation, potential evapotranspiration, lake evaporation and stream flow. Additional data analysis is required to complete a long-term water balance for both the lake and the basin in order to account for total hydrologic input.

Survival of Chinese Mitten Crab (Eriocheir sinensis) Larvae under Various Coast Ballast Water Transport and Discharge Scenarios
Monaca Noble
Monaca@pdx.edu
Major Professor: Mark Sytsma

Because of the concern that the Chinese mitten crab, Eriocheir sinensis, will spread from San Francisco Bay along the coast in ballast water, we conducted lab experiments to assess survivorship in ballast water and immediately following ballast water discharge. Larval survivorship under different management scenarios was simulated using rapid changes in salinity. We used larvae of stage zoea I and II from seven parent sets from San Francisco Bay. Gradual and immediate changes in salinity from 25ppt to 33ppt were used to simulate flow-through and empty-refill exchange. Salinity was held constant at 25ppt to simulate the no exchange treatment. Following each of the ballast water transport scenarios, surviving larvae were exposed to one of four discharge salinities (25ppt, 7ppt, 3ppt, 0ppt). There was no significant difference in survival rate between ballast water transport treatments indicating that those larvae not physically removed from the tank during one of two ballast water exchange techniques would likely survive transport. Larvae who survived transport treatments survived as well as the control when exposed to the discharged salinity of 25ppt, but had very low survival in 7ppt and 100% mortality on both 3ppt and 0ppt.

Base on the salinity tolerance and ability to survival rapid changes in salinity, the Chinese Mitten Crab would survive ballast water transport. Likewise, based solely on salinity, Chinese mitten crabs would likely survive ballast water discharge into high salinity water but not into low salinity water, such as that of the Columbia River.

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Productivity and growth rates of Egeria densa in the Sacramento-San Joaquin Delta, California
Toni G. Pennington
toni@pdx.edu
Major Professor: Dr. Mark D. Sytsma

Invasion of lakes and reservoirs by non-native submersed aquatic plants degrades water quality, limits navigability, and is aesthetically displeasing. Egeria densa is one of the most problematic aquatic plants in the Sacramento-San Joaquin Delta of California and the focus of intensive control measures. The purpose of this ongoing research is to improve the understanding of the life history of E. densa. Growth and photosynthetic response to light was measured monthly on E. densa shoots collected from Disappointment Slough in the Delta, beginning December 2003. Photosynthetic response to light was determined by incubating plant tips in 300-ml bottles at five light levels using neutral density shade cloth. Changes in pH and dissolved oxygen concentration were measured before and after 4h at ambient surface water temperature. Use of HCO3- by E. densa was suggested by pH of 10.18 at 20% of surface light (alkalinity = 1465 µmol). Other research analyzing pH drift by E. densa revealed similar values.
To date, maximum net photosynthetic rate was observed in July 2004 at 8.8 mg O2 . mg dry weight -1 . h-1 when surface water was 25 C. Growth rates were determined by tagging plants and measuring changes in apical growth after three to four weeks. When water temperature was ~ 11 C growth rates averaged 0.2 cm day-1 (±0.05 SE) in December 2003 and increased significantly to 0.7 cm day-1 (±0.08 SE) in April 2004 (water temperature 23 C) with some tips growing as much as 1 cm day-1. In contrast, growth rates of E. densa in a coastal Oregon lake were ~0.2 cm day-1 at 20 C and declined to 0.02 cm day-1 at 7 C.

Diatom Biogeography and Autecology in the Western US
Nadezhda Slavchova
nadezhds@pdx.edu
Major Professor: Dr. Yangdong Pan

Diatoms, as one of the most valuable bioindicators, have proven to give detailed picture and to provide a good assessment of the environmental conditions in highly variable habitats like rivers and streams. Despite 200-year research on diatoms, the potential of using them as a bioassessment tool has not been fully explored. Environmental Monitoring and Assessment Program (EMAP) sponsored by US EPA provides an excellent opportunity to enhance our knowledge on diatom ecology. The Western EMAP (WEMAP) sampled rivers and streams in 12 western states. All these rivers and streams were randomly selected using a probability-based sample survey design. The field crews from each state collected the samples during the low-flow periods (May to September) of years 2000-2004. Ten transects (cobbles, rocks or sediments, where rocks were not available) from 100m-long river segments were sampled. About 400-500 diatom samples per year were collected. The main objectives of this research project are: to characterize diatom geographical distribution patterns in the Western USA; to quantify the relationships between diatom assemblages and the environmental variables (e.g., chemistry, physical habitat conditions and landscape characteristics) in the Western USA; and to document the morphological variation of common diatoms and characterize their population variability in the Western US.

The Formation and Germination of Potamogeton crispus Turions in Blue Lake, Oregon:
The Best Time for Chemical Control
Steven W. Wells
sww@pdx.edu
Major Professor: Mark Sytsma

Potamogeton crispus (curly leaf pondweed) is an introduced aquatic plant identified as a nuisance species in the Blue Lake Integrated Aquatic Vegetation Management Plan developed by the Center for Lakes & Reservoirs. Once this plant is established, reproduction primarily occurs vegetatively through turions. Turions are modified stem apices (terminal and axillary); they are starch storage organs used for propagation and dispersal. The objective of the experiment is finding the best time for chemical control. Research addressed two questions: when does Potamogeton crispus in Blue Lake form the turions and when do these turions germinate? Mature and developing turions are sampled with a Petite Sonar( sediment dredge and a plant rake, while site characteristics are described using a DataSonde( 4A Hydrolab(. The first newly formed turion was found on Potamogeton crispus on April 5th while emergent flower buds were first reported on April 19th.

The latest sampling on September 9th revealed newly formed turions on plants. The turions were found germinating as early as November 6th but this will be reexamined in the fall. November to April is the optimal time for chemical control, coinciding with the plant's low period of carbohydrate storage and before the new turion cohort is produced.