Contributors (in alphabetical order)
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Chlorophyll aChlorophyll a concentrations measured from samples collected at various sites during the growing season between 1994 and 1997 did not display any clear patterns of increasing or decreasing levels (Table 24). However, data collected during the 1997 growing season were highly variable both temporally and spatially. Although not universal for all stations, the highest seasonal chlorophyll a levels were generally observed in June and were associated with an abundance of diatoms. There appears to be no distinct differences in the chlorophyll a levels between the Snake and Columbia river systems. Both the upstream Snake River station (SNR-148) and the McNary Reservoir station (CLR-295) had similar peak levels in June, which is in contrast to most other parameters. Table 24. Average and 95- percent confidence intervals for growing season Chlorophyll a concentrations (μg/L) in the surface water at selected sampling sites and years (Corps 1999).
Previous research suggests that average chlorophyll a levels above 5.0 and 14.5 mg/l are indicative of mesotrophic and eutrophic conditions, respectively. Chlorophyll a levels will typically range between 3.0 and 11.0 mg/l and 3.0 and 78.0 mg/l for mesotrophic and eutrophic conditions, respectively (Wetzel 1983). Concentrations of chlorophyll a generally are between the criteria for mesotrophic and eutrophic, with an average concentration between 3.8 and 11.4 mg/l, and an upper confidence interval (95%) of 18.9 mg/l for the period between 1994 and 1997. Based on estimated median concentrations for 1997, Station SNR-108, in the Lower Granite Reservoir, had the highest median chlorophyll a level of 8.74 mg/l, and a mean concentration of 8.1 mg/l. In the Snake River, there was a general progressive decline in levels moving downstream with the seasonal median level for Station SNR-18 in the Ice Harbor Reservoir at 3.2 mg/l (and a mean concentration of 5.6 mg/l). The opposite was true in the Columbia River where the median concentrations appeared to increase downstream. The median concentration at the upstream station (CLR-397) was 6.72 mg/l and gradually increased to 8.01 mg/l at Station CLR-295 in the McNary Reservoir. Given the relatively low chlorophyll a levels measured at Ice Harbor, it is unclear as to whether the increase in the Columbia River is attributable to inputs from the Snake River. PhytoplanktonThere were few differences in the number and types of phytoplankton observed at the impounded pool sites above dams and transitional sites below dams within the Lower Snake River system. For most of the study area, diatoms (Bacillariophyta) were typically dominant throughout much of the season, but especially during the peak flow period. At this time, diatoms typically accounted for more than 90% phytoplankton biovolumes. The cryptophytes (Rhodomonas minuta and R. m. nannoplanctica) became dominant or co-dominant (by numerical density) at most sites in the lower 50 miles of the Snake River during the second half of the season. However, because of their small size, they comprised a relatively small fraction of assemblage biovolume. Phytoplankton blooms (dominated by the genus Aphanizomenom and Anabaena) do occur in the Lower Snake River reservoirs. These blooms are typically brief, lasting only a few weeks, but significant in their total community dominance during that time period and potential subsequent impacts on oxygen concentrations and invertebrate food supply. There have been documented occurrences of surface scum resulting from these taxa. Research has noted much littoral detrital accumulation from senescing planktonic algae blooms during the later summer that deposits on attached benthic algal communities. This senescing planktonic algae likely provides a significant late-summer nutrient input to the attached benthic algal communities, as well as a direct food source for littoral benthic macroinvertebrates. Other commonly observed taxa within the lower Snake River reservoirs include the diatoms Melosira islandica (18.3% of the total collection), Cyclotella meneghiniona (11.7%) and Fragillaria crotonensis (11.3%), and the cryptophytes Rhodomonas minuta (7.3%) and its variant R. m. nannoplanctica (14.4%). Few other taxa exceeded 2% of the total collection except the diatom species Asterionella formosa (4.5%) and Melosira granulata (3.7%), diatoms of the genera Diatoma (5.3%) and Synedra (3.4%), the green algal genus Scenedesmus (2.3%), and the blue-green Anabaena spp. (4.3%). Attached benthic algae are a secondary source of primary productivity in the Lower Snake River. As algae that are attached to rocks and other hard substrate, they provide a food source for benthic organisms such as aquatic insect larvae, amphipods, and oligochaetes. The 1997 empirical data on ABA were based primarily on measurements of chlorophyll a concentrations samples collected from tile and mylar substrates placed in the field for a 14-day incubation period. Mean concentrations (mg/m²) of five "species" of photosynthetic pigments (evaluated from tile substrates) were reported including chlorophyll a (mono-and trichromatic), b, and c, and phaeophytin. The upstream station (SNR-148) had consistently high values of the chlorophyll a throughout the season ranging from 29.06 to 93.6 mg/m² with the highest value occurring in October. Only the downstream station in the Ice Harbor Reservoir (SNR-18) had chlorophyll a values that were higher, which were frequently above 100 mg/m² from July through early September. In the Lower Granite Reservoir (SNR-118), the ABA chlorophyll a values ranged from 23.04 to 73.35 mg/m², which are generally lower than that recorded at the upstream station SNR-148. Trichromatic chlorophyll a levels (the measure of chlorophyll used in the 1975 and 1976) EPA surveys of Falter et al. (1976) measured in the high-flow year 1997 at the free-flowing SNR-148 were in the 30-100 mg/m² range at 1.5 m depth. In the low-flow 1998, the range was 60-110 mg/m² at 1.5m depth. The ABA trichromatic chlorophyll a levels obtained in 1975 and 1976 at this site were 10-20 mg/m². There was essentially no overlap between the ranges of 1976 and 1997-98. The earlier data are from glass-slide incubations while the later data are from a combination of natural rock, tile, and a mylar substrate. Even though substrates were different, these ABA data over the 24-year time spread are probably one of the better indicators available of increasing productivity of the Snake River coming into the project area over this time period. The mean biomass, as measured by the ash-free, oven dry weights (AFODW), for the attached benthic algae samples collected in 1997 follows a similar pattern with the Ice Harbor Reservoir station (SNR-18) having highest biomass of 10.94 to 37.09 g/m². The AFODW for the Lower Granite Reservoir samples (SNR-118) ranged from 9.09 to 25.25 g/m². Samples from the upstream lower Snake station (SNR-148) had ADOFWs ranging between 4.39 and 15.17 g/m². Historical data indicate that ABA ash-free biomass in 1976 averaged 1.64 g/m² at SNR-148. In contrast, the results from 1997, when samples collected from a comparable depth and time period and a non-silt collecting mylar substrate, averaged 6.65 g/m², and in 1998 7.95 g/m. The different measure of ABA ash-free biomass further suggests that productivity in the Lower Snake River is increasing. AFODW samples collected from the upper McNary Reservoir (CLR-326) had AFODWs ranging from 2.26 to 30.27 g/m² with the highest level occurring later in the season toward the end of September. Samples collected in the free-flowing Hanford section (CLR-369) had relatively low biomass values with AFODWs for most samples below 6.0 g/m² and a seasonal range of 0.64 to 14.09 g/m². The McNary Reservoir and the Lower Snake River Reservoirs apparently produce a considerable amount of attached benthic algae biomass along the littoral and shoreline areas. However, much of the system has accumulated fine sediments, which limit the amount of ABA and epilithic periphyton. This finding may prove interesting in evaluating the proposed natural river drawdown alternative, because ABA is generally more prolific in riverine conditions rather than in a reservoir environment. TributariesAlpowa CreekAlpowa Creek drains an agriculturally dominated watershed. Sediment levels (both concentration and turbidity), stream temperature, and fecal coliform are three major water quality parameters of concern in this watershed. In 1981, Stream temperature during the summer months and high sediment loads especially during winter and spring high flows were recognized as water quality problems for fish in Alpowa Creek (Mendel and Taylor 1981). The WDOE surface water quality standards identify Alpowa Creek as a Class A stream. The classification of a water body in the state of Washington is based on its beneficial uses. Data to assess the water quality of Alpowa Creek are limited to studies conducted in 1981 (Mendel and Taylor 1981; Soil Conservation Service 1981) and a current monitoring effort by the WSU, Center for Environmental Education (CEE) for the PCD. Because the latter project began in September 1998, data is not yet available to assess stream temperature as a potential limiting factor to native fish during the summer of 2000. Data collected during 2000 will result in some interpretations as to when and where in the watershed stream temperature may limit fish habitat. The purpose of the collaborative CEE/PCD project is to assess the success of agricultural management practices within the Alpowa Creek watershed. The monitoring protocol focuses on the most critical water quality parameters identified in the watershed: stream temperature, sediment, and fecal coliform. These parameters are measured every two weeks. Additional parameters, measured every two months, include: ammonia, nitrate, total Kjeldahl nitrogen (TKN), and total phosphorus (TP). Stream discharge is measured at three stations monthly, and storm events are sampled when they occur. Benthic macroinvertebrates are collected quarterly and were first collected in the spring of 1999. Three monitoring sites are established on Alpowa Creek (Figure 11). 
Figure 11. Alpowa Creek Monitoring Sites. One critical water quality problem in Alpowa Creek is elevated water temperature, especially during mid-summer (Soil Conservation Service (SCS) 1981; Mendel and Taylor 1981). Reduced base flow, summer irrigation withdrawals, and a lack of riparian vegetative cover along many stretches are likely contributors to high summer temperatures. The middle and lower reaches of Alpowa Creek support grazing and agriculture activities that have removed much of the woody riparian and streambank vegetation. Water temperature exceeded WDOE standards for a Class A stream (18C) during September 1998 (Figure 12). Considering the temperature in September was 19C (Center for Environmental Education 1999), it is probable that the average water temperature during July and August may also be higher than the WDOE standard. Although recent temperature data are not available from April to August, temperature trends during this period were measured in 1981 (Mendel and Taylor 1981). Minimum and maximum stream temperatures were recorded at three locations in Alpowa Creek during the summer 1981. The upstream site (IFG) was located 5.5 miles upstream of the junction of Alpowa Road and Highway 12 (SW 1/4, SE 1/4, section 27, T 11N, R 43E), middle site at 1.2 miles upstream of the junction below the bridge at Weisenfel’s (SW 1/4, NW 1/4, section 20, T 11N, R 44E), and the downstream site at Wilson’s bridge about 30 feet below the dam (between sections 25 and 30, T 11N, R 45E). By late May 1981, stream temperature at the upstream station reached at least 21C. Considerably warmer temperatures were measured later in the summer (Table 25). While it is impossible to know, given this data, what percentage of the time stream temperatures exceeded a specific critical level (i.e., 18C as considered by WDOE for Class A waters), these water temperatures are clearly unfavorable to native salmonids during critical life history periods (Table 26). In many cases, maximum stream temperatures during mid-summer are more extreme and potentially lethal for some native fish species. Two temperature observations were made at the mouth of Alpowa Creek on July 22 and 23, 1975. At 4 pm on July 22, stream temperature was 28.8C, and at 1:35 pm on July 23, it was 27.3C (Environmental Protection Agency 1975, cited in Environmental Protection Agency 1999). Steelhead fry emerge from the substrate in Alpowa Creek probably between May and July, and juveniles are rearing through the summer months when temperatures are highest, posing a potential stress during these life history periods. Additional data found for Alpowa Creek were from late February through June, 1989 (Environmental Protection Agency 1999; (Table 27)). The limits of this data are that temperature and flow were not measured regularly, continuously, or at the same time of day. Still, they provide some indication of potential limitations for migrating adult steelhead and juvenile rearing. From September 1998 through March 1999, the temperature of Alpowa Creek varied from site to site. Generally, temperature increases in a downstream direction. With the exception of September, the average temperature of Alpowa Creek (October –March) at site 3 was higher than Alpowa 1 and 2. During September (and most likely throughout the summer) the temperature increased with a decrease in streamflow. This trend is most likely a result of summer irrigation diversions, which reduce stream flow and quantity, increasing temperature. 
Figure 12. Average Monthly stream temperature of Alpowa Creek, September 1998—March 1999. Table 25. Maximum and minimum stream temperatures (C) at three locations in Alpowa Creek during 1981 (modified from Mendel and Taylor 1981).
Table 26. Temperature requirements during life history periods for steelhead.
Table 27. Mean monthly stream temperature and discharge in Alpowa Creek during 1989.
Since the confluence of Pow Wah Kee Gulch with Alpowa Creek is above the Alpowa 1 site and below the Alpowa 2 site, one would assume slightly higher temperatures at Alpowa 1 than at Alpowa 2. This assumption is not supported by the data. One possibility is that one or more of the unlabeled springs that feed Alpowa Creek above Alpowa 3 may be warm or hot springs, which may have contributed to the temperature differences. Additional information on Alpowa Creek water quality may be available on a qualitative basis through communication with long-time local landowners. For example, during the 1996 floods many reaches of rivers in the Tucannon sub-basin were damaged and altered as a result of scouring streambeds and banks (B. Bowe, WSU Biological Systems Engineering, personal communication May1999). Each of these mechanisms can potentially increase stream temperature by exposing large amounts of cobble that act as solar collectors, and by reducing vegetative cover on the stream banks. As the monitoring projects of the PCD and CEE continue, trends in the data will emerge. 
Figure 13. Water temperature (C) of Alpowa Creek at three sample sites (Center for Environmental Education 1999). Total suspended solid concentrations varied seasonally and among the three stations. From mid-December to mid-January, Alpowa 1 and Alpowa 2 exceeded 80 mg/L. From mid-February to mid-March the TSS concentration at all three sites exceeded this level (Figure 13). At the end of December, TSS at Alpowa 2 was 181 mg/L, while in early March TSS at Alpowa 1 was 151 mg/L (Center for Environmental Education 1999). The seasonal variation in TSS generally coincides with peaks in stream discharge. The higher TSS in December probably is due to a rain-on-snow event. Stream discharge increases in response to precipitation or snowmelt in the watershed. High winter precipitation and snowmelt during spring increase runoff, and therefore produce more sediment in the watershed. When precipitation is the major factor influencing sedimentation to Alpowa, as the peak in December represents, Alpowa 2 samples contain the highest TSS concentrations. However, when spring snowmelt is the driving factor of TSS in the creek, TSS in Alpowa 1 exceeds that of Alpowa 2. In general, with the exception of Alpowa 2, spring snowmelt and precipitation account for higher TSS concentrations than precipitation alone during the winter. On January 15, 1999 during a storm event, TSS measured 2170 mg/L at Alpowa 1 (Center for Environmental Education 1999). The WDOE standard for fecal coliform in a Class A stream is that waters must not exceed a geometric mean of 100 cfu/100 ml. In addition, not more than 10% of all samples tested may exceed a geometric mean of 200 cfu/100 mL. In general, Alpowa Creek exceeds the WDOE standard of 100 cfu/ 100 mL every month tested with the exception of February (Figure 14). Fecal coliform bacteria are microscopic animals that live in the intestines and excrement of warm-blooded The geometric mean fecal coliform level from Alpowa Creek during September 1998-March 1999 were 161 cfu/100 mL, exceeding the WDOE standard of 100 cfu/100 mL. Of 39 data values, 38% of them exceeded 200 cfu/100 mL. The highest coliform levels were from Alpowa 2 during December and January (Figure 15). Livestock feedlots were observed at this location and near Alpowa 3, indicating this as a possible source of fecal coliform to the creek. There are also approximately eight ranch homes (B. Bowe, WSU Biological Systems Engineering, personal communication May 1999) in the area, or upstream, that may have failing septic systems. It is difficult to evaluate contamination from these sources as they lay underground, and testing requires the cooperation of the property owner. While waste from livestock in the area is considered to be the major source of coliform in Alpowa Creek, this assumption remains questionable due to the comparably low coliform levels at Alpowa 1. As this site is downstream of Alpowa 2 and livestock feedlots are also in the area, one would expect fecal coliform levels at this site to be comparable, if not higher, than those of samples taken at Alpowa 2. Streamflow measurements taken in Alpowa Creek during 1981 ranged between 6.7-7.1 cubic feet per second (cfs) between May 5 and October 22 (Mendel and Taylor 1981). Streamflow data is also available during the spring and early summer of 1989 (Table 25). There appears to be adequate stream flow to allow most salmonids to migrate through the system during the summer. Stream temperature, however, is the limitation during this period. Stream flow data recorded by the USGS during the early 1970’s in the headwaters of Alpowa Creek at Peola (# 13343510) and in the downstream portion of Alpowa Creek at Clayton Gulch (# 13343520) indicate that the storm events in the upstream and downstream areas occur at different times. For example, when flow at Peola on January 9, 1971,was only 0.5 cfs, at Clayton Gulch it was 270 cfs on the same day. Recent field reconnaissance in the Clayton Gulch watershed shows evidence of a substantial amount of sediment and debris flow from past flood events. In the current water quality monitoring effort, discharge measurements are not available for Alpowa 2 and Alpowa 3 sites. Consequently, it is difficult to predict change in water quality at different flow regimes. 
Figure 14. Geometric mean of monthly fecal coliform in Alpowa Creek, September 1998-March 1999 (Center for Environmental Education 1999). 
Figure 15. Geometric mean of monthly fecal coliform levels by site from September 1998-March 1999. Table 28. Nitrate and total phosphorus concentration in Alpowa Creek (Center For Environmental Education 1999).
Total phosphorus concentrations in all three sampling sites in Alpowa exceeded the limit of 0.05 mg/L except at Alpowa 2. No specific trend was found with the limited samples, but a general trend is that Alpowa 1 site had higher TP concentrations during November and January samplings. It is also evident from January samplings that TP is higher during high discharge in the creek than at other times. The only previous nutrient data for Alpowa Creek was collected on September 11, 1981 at an upstream site (IFG) and another site (R). Total phosphorus measured 0.07 ppm and 0.12 ppm respectively at these sites. Nitrate concentrations at the same two sites were 0.28 ppm and 0.29 ppm (Table 28). Deadman CreekSediment levels (both concentration and turbidity), stream temperature, and fecal coliform are three major water quality parameters of concern in this watershed. Stream temperature during summer months and high sediment loads during winter and spring high flows are water quality problems for fish in Deadman Creek. The WDOE surface water quality standards identify Deadman Creek as a Class A stream. The classification of a water body in the state of Washington is based on its beneficial uses. Data to assess the water quality of Deadman Creek are limited to a water quality-monitoring project currently underway with the WSU CEE for the PCD. Because the project began in September 1999, data collected during the summer of 2000 and 2000 (Table 29) will allow us to make some interpretations as to when and where in the watershed stream temperature may limit fish habitat. Three monitoring sites are established on Deadman Creek (Figure 16). One critical water quality problem in Deadman Creek is elevated water temperature, especially during mid-summer. Reduced base flow, summer irrigation withdrawals, and a lack riparian vegetative cover along many stretches are the likely contributors to these high summer temperatures. The entire length of Deadman Creek support grazing and agriculture activities, which have removed much of the woody riparian and streambank vegetation. Water temperature exceeded WDOE standards for a Class A stream (18C) from May - September 1999. While it is impossible to know, given this data, what percentage of the time stream temperatures exceeded a specific critical level (i.e., 18C as considered by WDOE for Class A waters), these water temperatures are clearly unfavorable to native salmonids during critical life history periods (Table 30). In many cases, maximum stream temperatures during mid-summer are more extreme and potentially lethal for some native fish species. Steelhead fry may emerge from the substrate in Deadman Creek probably between May and July, and juveniles are rearing through the summer months when temperatures are highest, posing a potential stress during these life history periods. 
Figure 16. .Deadman Creek Monitoring Sites (WSU/CEE 1998-2000). Table 29. Water Quality Sampling Data for Deadman Creek (WSU/CEE 1998-2000)
Table 30. Temperature requirements during life history periods for steelhead
a Bell 1986: b Beschta et al. 1987 c Hicks 1999 From September 1998 - March 1999, water temperatures in Deadman Creek varied from site to site. During September (and most likely throughout the summer) the temperature increased with a decrease in streamflow. This trend is most likely a result of summer irrigation diversions, which reduce stream flow and quantity, increasing temperature. Additional information on Deadman Creek water quality may be available on a qualitative basis through communication with long-time local landowners. For example, during the 1996 floods many reaches of rivers in the Tucannon sub-basin were damaged and altered as a result of scouring streambeds and banks (B. Bowe, WSU Biological Systems Engineering, personal communication May1999). Each of these mechanisms can potentially increase stream temperature by exposing large amounts of cobble that act as solar collectors, and by reducing vegetative cover on the stream banks. As the monitoring projects of the PCD and CEE continue, trends in the data will emerge. Total suspended solid concentrations varied seasonally among the three stations. The seasonal variation in TSS generally coincides with peaks in stream discharge. The higher TSS in December probably is due to a rain-on-snow event. Stream discharge increases in response to precipitation or snowmelt in the watershed. High winter precipitation and snowmelt during spring increase runoff, and therefore produce more sediment in the watershed. Precipitation is the major factor influencing sedimentation to Deadman. An overall average for the Deadman Watershed is 42.71 at the mouth. This is about ½ the upper limit for optimum health of salmonids. Fecal coliform in Deadman Creek exceeds the WDOE standard of 100 cfu/ 100 mL about 50% of the tests with the overall averages above the standard. The geometric mean fecal coliform level from Deadman Creek exceeds the WDOE standard of 100 cfu/100 mL. It is difficult to evaluate contamination from any one source. Waste from livestock in the area is considered to be the major source of coliform in Deadman Creek Streamflow measurements taken in Deadman Creek during May through July 1999 ranged between 2.5-5.3 cubic feet per second (cfs). There appears to be adequate stream flow to allow most salmonids to migrate through the system during the summer. Stream temperature, however, is the limitation during this period. The WDOE does not have standards for phosphorus and nitrogen in surface waters. Total phosphorus concentrations in all three sampling sites in Deadman exceeded the limit of 0.05 mg/L. VegetationAsherin and Claar (1976) inventoried the riparian habitats and associated wildlife along the Lower Snake River for the Corps of Engineers. They found a total of 49 different vegetative and land forms along the Lower Snake River. Table 31 lists a total of 345 different species of plants found within the Lower Snake River summary area (Ashern and Claar 1976; ACOE 1976). Table 31. Plants found in the Lower Snake River subbasin. Common Name Scientific Name Subalpine fir Abies lasiocarpa Grand fir Abies grandis Mountain maple Acer glabrum Box elder Acer negundo Silver maple Acer saccharinum Common yarrow Achillea millefolium Russian knapweed Acroptilon repens Jointed goatgras Aegilops cylindrica Horsechestnut Aesculus hippocastanum Agoseris Agoseris gradiflora Crested wheatgrass Agropyron cristatum Thickspike wheatgrass Agropyron dasystachyum Intermediate wheatgrass Agropyron intermedium Quackgrass Agropyron repens Bluestem wheatgrass Agropyron smithii Blue bunch wheatgrass Agropyron spicatum Slender wheatgrass Agropyron trachycaulum Redtop bentgrass Agrostis alba Tree of Heaven Ailanthus altissima American waterplantain Alisma plantago-aquatica Giant onion Allium geyeri var. tenerum White alder Alnus rhombifolia Sita alder Alnus sinuata Pale alyssum Alyssum alyssoides Thumbleweed amaranth Amaranthus graecizans Powell amaranth Amaranthus powellii Redroot amaranth Amaranthus retroflexus Bur ragweed Ambrosia acanthicarpa Common ragweed Ambrosia artemisiifolia Saskatoon serviceberry Amelancier alnifolia Tarweed fiddleneck Amsinckia lycopsioides Menzies fiddleneck Amsinckia menziesii Rigid fiddleneck Amsinckia retrorsa Tessellate fiddleneck Amsinckia tesselata Common bugloss Anchusa officinalis Field camomile Anthemis arvensis Mayweed camomile Anthemis cotula Bur Chervil Anthriscus scandicina Smooth Indian hemp Apocynum cannabinum Mouseearcress Arabidopsis thaliana Common burdock Arctium minus Sandwort Arenaria pusilla Thymeleaf sandwort Arenaria serpyllifolia Threeawn Aristida longiseta Common wormwood Artemisia absinthium Tarragon Artemisia drancunculus Sagebrush Artemisia leibergii Sagebrush Artemisia lindleyana Louisiana sagebrush Artemisia ludoviciana Stiff sagebrush Artemisia rigida Big sagebrush Artemisia tridentata Showy milkweed Asclepias speciosa Garden asparagus Asparagus officinalis Aster Aster campestris Aster Aster spp. Western aster Aster occidentalis Milk-vetch Astragalus arrectus Hairy milk-vetch Astragalus inflexus Pursh locoweed Astragalus purshi Spaulding’s milk-vetch Astragalus spauldingii Milkvetch; locoweed Astragalus spp. Piper’s milk-vetch Atragalus riparius Wild oat Avena fatua Arrowleaf balsamroot Balsamorhiza sagittatta Water birch Betula occidentalis Paper birch Betula papyrifera Nodding beggerticks Bidens cernua Beggerticks Bidens frondosa Tall beggerticks Bidens vulgata Blepharipappus Blepharipappus scaber Bolandra Bolandra oregana Mustards Brassica spp. Douglas brodiea Brodiaea douglasii Rattlesnake brome Bromus brizaeformis Japanese brome Bromus japonicus Soft brome Bromus mollus Ripgut brome Bromus rigidus Barren brome Bromus sterilis Cheatgrass Bromus tectorum Green-banded mariposa lily Calochortus macrocarpus maculosus Broad-fruit mariposa lily Calochortus nitidus False Flax Camelina microcarpa Shepherd’s Purse Capsella bursa-patoris Hoary cress Cardaria draba Musk thisle Carduus nutans Green sedge Carex oederi Raynold’s sedge Carex raynoldsii Sedge Carex spp. Chestnut Castanea mollissima Douglas hackberry Celtis douglasii (reticulata) Cornflower Centaurea cyanus Diffuse knapweed Centaurea diffusa Spotted knapweed Centaurea maculosa Yellow starthistle Centaurea solstitialis Bachelor’s button Centaurea spp. Starry chickweed Cerastium arvense Sticky cerastium Cerastium viscosum Douglas chaenactis Chaenactis douglasii Lambsquarter’s Chenopodium album Wormseed goosefoot Chenopodium ambrosioides Jerusalem oak Chenopodium botrys Red goosefoot Chenopodium rubrum Rush skeletonweed Chondrilla juncea Chorispora Chorispora tenella Golden Aster Chrysopsis hispida Rubber rabbitbrush Chrysothamnus nauseosus Tall green rabbitbrush Chrysothamnus viscindiflorus Common chicory Cichorium intybus Tuber waterhemlock Cicuta vagans Canada thistle Cirsium arvense Thistle Cirsium brevistylum Wavy-leaf thistle Cirsium undulatum Bill thistle Cirsium vulgare Minerslettuce Claytonia perfoliata Yellow spider flower Cleome lutea Tonella Collinnnsia floribunda Bristle-flowered collomia Collomia macrocalyx Poison hemlock Conium maculatum European morningglory Convolvulus arvensis Horseweed Conyza canadensis Black hawthorn Crataegus douglasii Tapertip hawksbeard Crepis acuminata Slender hawksbeard Crepis atrabarba Common crupina Crupina vulgaris Chufa Cyperus esculentus Clustered lady slipper Cyprepidium fasciculatum Jimsonweed Datura stramonium Pinnate tansymustard Descurainia pinnata Mountain tansymustard Descurainia richardsonii Venuscup teasel Dipsacus sylvestris Saltgrass Distichlis alkali Spring draba Draba verna Barnyardgrass Echinochloa crusgalli Russian olive Elaeagnus angustifolia Needle spikesedge Eleocharis acicularis Common spikerush Eleocharis palustria Giant wildrye Elymus cinereus Creeping wildrye Elymus triticoides Fireweed Epilobium angustifolium Glandulosum willowweed Epilobium glandulosum Autumn willowweed Epilobium paniculatum Willowweed Epilobiu m spp. Field horsetail Equisetum arvense Western scouringrush Equisetum hyemale Smooth scouringrush Equisetum laevigatum Marsh horsetail Equisetum palustre Horsetail Equisetum spp. Stinkgrass Eragrostis cilianensis Threadleaf fleabane Erigeron filifolius Shaggy fleabane Erigeron pumilus Fleabane Erigeron speciosus Daisy fleabane Erigeron strigosus Eriogonum composition Wyeth eriogonum Eriogonum heracleoides Canyon heather Eriogonum niveum Eriogonum Erigonum spp. Storksbill Erodium cicutarium Woolly eriophyllum Eriophyllum lanatum Western wallflower Erysimum asperum Ridge-seeded spurge Euphorbia glyptosperma Leafy spurge Euphorbia esula Tall fescue Festuca arundinacea Idaho fescue Festuca idahoensis Rattail fescue Festuca myuros Fescue Festuca occidentalis Sixweeks fescue Festuca octoflora English fescue Festuca pratensis Rough fescue Festuca scabrella Sandbur Franseria acanthicarpa Yellow fritillary Fritillaria pudica Blanket flower Gaillardia aristata Bedstraw Galium aparine Gaura; velvet weed Gaura parviflora Geranium Geranium viscosissimum Slenderleaf gilla Gilla linearis Mannagrass Glyceria spp. American licorice Glycyrrhiza lepodota Cottonbatting cudweed Gnaphalium chilense Cudweed Gnaphalium palustre Gum plant Grindelia nana Gum plant Grindelia squarrosa Sneezeweed Helenium macranthum Common Sunflower Helianthus annuus Helianthella; sunflower Helianthus uniflora Salt heliotrope Heliotropium curassavicum Alum root Heuchera cylindrica Orange hawkweed Hieracium aurantiacum Meadow hawkweed Hieracium pratense Oceanspray Holodiscus discolor Foxtail barley Hordeum jubatum Wall barley Hordeum leporinum Mouse barley Hordeum murinum Ballhead waterleaf Hydrophyllum capitatum Common St. Johnswort Hypericum perforatum Iris Iris spp. Poverty sumpweed Iva axillaris Common Juniper Juniperus communis Western juniper Juniperus occidentalis Rocky Mountain juniper Juniperus scopulorum Black walnut Juglans nagens Persian walnut Juglans regia Belvedere summer cypress Kochia scoparia Prickly lettuce Lactuca serriola Slender rabbit leaf Lagophylla ramosissima Henbit deadnettle Lamium amplexicaule Western larch Larix occidentalis Common duckweed Lemna minor Prairie pepperweed Lepidium densiflorum Broadleaf peppergrass Lepidium latifolium Clasping pepperweed Lepidium perfoliatum Virginia pepperweed Lepidium virginicum Dalmatian toadflax Linaria genistifolia dalmatica Yellow toadflax Linaria vulgaris Perennial flax Linum perenne Woodlandstar Lithophragma bulbifera Smallflower woodlandstar Lithophragma parvilflora Stoneseed Lithospermum arvense Western gromwell Lithospermum ruderale Lomatium Lomatium disectum Gray’s biscuitroot Lomatium grayi Nineleaf lomatium Lomatium triternatum Riverbar deervitch Lotus denticulatus Spanish clover Lotus purshianus Velvet lupine Lupinus leucophyllus Silky lupine Lupinus sericeus Lupines Lupinus spp. Sulfur lupine Lupinus sulphureus Lychnis Lychnis coronaria American bugleweed Lycopus americanus Rough bugleweed Lycopus asper Purple loosestrife Lythrum salicaria Hollygrape Mahonia repens Cheeses Malva neglecta Common horehound Marrubium vulgare Pepperwort Marsilea vestita Scentless May-weed Matricaria maritima Black medic Medicago lupulina Alfalfa Medicago sativa White sweet clover Melilotus alba Yellow sweetclover Melilotus officinalis Sweetclover Melilotus spp. Mint Mentha arvensis Rough blazingstar Mentzelia laevicaulis Monkey flower Mimulus guttatus Carpetweed Mollugo verticillata White mulberry Morus alba Red mulberry Morus rubra Mosses Moss spp. Bay Forget-me-not Myosotis laxa Forget-me-not Myosotis micrantha Catnip Nepeta cataria Common eveningprimrose Oenothera biennis Scotch thistle Onopordum acanthium Plains prickly pear Opuntia polyacantha Indian ricegrass Oryzopsis hymenoides Old witchgrass Panicum capillare Scribner panicum Panicum scribnerianum Parietaria Parietaria occidentalis Virginia creeper Parthenocissus quinquefolia Beard-tongue Penstemon triphyllus Prairie clover Petalostemon orantum Varileaf phacelia Phacelia heterophylla Silverleaf phacelia Phacelia leucophylla Threadleaf phacelia Phacelia linearis Reed canarygrass Phalaris arundinacea Syringa; mockorange Philadelphis lewisii Timothy Phleum pratense Common Twinpod Physaria didymocarpus didymocarpus Popcornflower Plagiobothrys tenellus Indian wheat Plantago patagonica Longleaf phlox Phlox longifolia Field pea Pisum arvense Buckhorn plantain Plantago lanceolata Woolly indianwheat Plantago purshi Engelmann spruce Picea Engelmannii Whitebark pine Pinus albicaulis Lodgepole pine Pinus contorta Limber pine Pinus flexilis Western white pine Pinus monticola Ponderosa pine Pinus ponderosa Patagonia Indianweed Plantago patagonica Longhorn plectritis Plectritis macrocera Bulbous bluegrass Poa bulbosa Canda bluegrass Poa compressa Howell’s bluegrass Poa howellii Bluegrass Poa interior Wheeler bluegrass Poa nervosa Nevada bluegrass Poa nevadensis Kentucky bluegrass Poa pratensis Sandberg bluegrass Poa sandbergii Littlebells polemonium Polemonium micrathum Rabbitfoot polypogan Polypogon monspeliensis Prostrate knotweed Polygonum aviculare Knotweed Polygonum coccineum Swamp knotweed Polygonum hydropiperoides Curlytop ladysthumb Polygonum lapathifolium Knotweed Polygonum majus Dotted smartweed Polygonum punctatum Sakhalin knotweed Polygonum sachalinense Licorice-root fern Polypodium vulgare Rabbitfoot polypogon Polypogon monspeliensis Balsam poplar Populus balsomifera Great plain cottonwood Populus deltoides Lombardy popular Populus nigra Quaking Aspen Populus tremuloides Black cottonwood Populus trichocarpa Common purslane Portulaca oleracea Fennelleaf pondweed Potamogeton pectinatus Cinquefoil Potentilla r ecta Douglas fir Pseudotsuga menziesii Lanceleaf scurfpea Psoralea lancelata Common apricot Prunus armeniaca Mahaleb cherry Prunus mahaleb Peach Prunus persica Stone fruit Prunus spp. Blackthorn Prunus spinosa Chokecherry Prunus virginianus Antelope bitterbrush Purshia tridentata Common pear Pyrus communis Cultivated apple Pyrus malus Small flowered buttercup Ranunculus abortivus Buttercup Ranunculus purshii Buttercup Ranunculus uncinatus Cascara buckhorn Rhamnus purshiana Smooth sumac Rhus glabra Poison ivy Rhus radicans Skunkbrush Rhus trilobata Golden current Ribes aureum Wax current Ribes cereum Black current Ribes hudsonianum Snow gooseberry Ribes niveum Black locust Robinia pseudoacacia Watercress Rorippa nasturitium-aquaticum Arc cress Rorippa curvisiliqua Cultivated rose Rosa spp. Wild rose Rosa woodsii Evergreen blackberry Rubus laciniatus Northwest raspberry Rubus nigerrimus Trailing blackberry Rubus macropetalus Blackeyedsusan Rudbeckia hirta Sheep sorrel Rumex acetosella Yellow or curly dock Rumex crispus Western dock Rumex occidentalis Willow dock Rumex salicifolius Veiny dock Rumex venosus Duckpotato arrowhead Sagittaria cuneata Peachleaf willow Salix amygdaloides Whiplash willow Salix caudata Coyote willow Salix exigua Pacific willow Salix lasiandra MacKenzie willow Salix rigida Common Russianthistle Salsola kali Russian thistle Salsola pestifer Blue elderberry Sambucus glauca Tule bulrush Scirpus acutus American bulrush Scirpus americanus Softstem bulrush Scirpus validus Narrowleaf skullcap Scutellaria angustifolia Rye Secale cereale Rye Secale montanum Stonecrop Sedum douglasii Wallace selaginella Selaginella wallacei Yellow foxtail Setaria glauca Foxtail Setaria d isveri Tumbleweed mustard Sisymbrium altissimum Hedge mustard Sisymbrium officinale Hansen squirreltail Sitanion hystrix Bittersweet Solanum dulcamara Silverleaf nightshade Solanum elaeagnifolium Buffalobur Solarum rostatum Nightshade Solanum sarrachoides Canada goldenrod Solidago canadensis Giant goldenrod Solidago gigantea Elegant goldenrod Solidago lepida Missouri goldenrod Solidago missouriensis Western goldenrod Solidago occidentallis Goldenrod Solidago spp. Common sowthistle Sonch us oleraceus Johnsongrass Sorghum halepense Salmon globe mallow Sphaeralcea munroana Maple-leaved mallow Sphaeralcea rivularis Spirea Spirea trichocarpa Sand dropseed Sporobolus cryptandrus Chickweed Stellaria media Starwort Stellaria washingtonia Flowering straw Stephanomeria tenuifolia Needle-and-thread grass Stipa comata Australian peavine Swainsona salsula Columbia snowberry Symphoricarpos rivularis Common lilac Syringa vulgaris Medusahead wildrye Taeniatherum asperum Tamarisk Tamarix parviflora Tansy Tanacetum vulgare Dandelion Taraxacum officinale Pacific yew Taxus brevifolia Thelypodium Thelypodium laciniatum Arbor vitae Thuja occidentalis Western redcedar Thuja plicata Western poison ivy Toxicodendron radicans Goatsbeard Tragopogon dubuis Goatsbeard Tragopogon miscellus Puncture vine Tribulus terrestris Douglas’ Trifolium douglasii Common wheat Triticum aestivum Western hemlock Tsuga heterophylla Mountain hemlock Tsuga mertensiana Narrowleaf cattail Typha angustifilia Cat-tail Typha latifolia Chinese elm Ulmus parvifolia Big stinging nettle Urtica dioica Slim nettle Urtica gracilus Cow soapwort Vaccaria segetalis Moth mullein Verbascum blattaria Flannel mullein Verbascum thapsus Bigbract verbena Verbena bracteata American speedwell Veronica americana Water speedwell Veronica anagallis Common speedwell Veronica arvensis Purslane speedwell Veronica peregrina Hairy vetch Vicia villosa Grapevine Vitis spp. Cocklebur Xanthium strumarium Common poolmat Zannichellia palustria TributariesAlpowa CreekOne of the earliest recorded observations of vegetation around Alpowa Creek dates back to October 1854, when the stream was described as being is from eight to ten yards wide and fifteen inches deep and bordered by willow, long-leaved cotton-wood, birch, sumac, cherry, white haw, honeysuckle and gooseberry. The left bank of the stream was described with “very good grass and an abundance of wood” (Brauner 1976). The native riparian vegetation of the area was characterized by shrubby thickets, patches of deciduous trees, and grass-dominated plant communities. Conifer trees, predominantly ponderosa pine and douglas fir, were historically more common than today. A broad scale analysis of the changes in wetland distribution by researchers at the University of Idaho indicates a 97% reduction in the Palouse Bioregion. Most of these wetlands were drained or filled to increase the land available for agricultural and ranching uses (Black et al 1997). The predominant upland vegetation types were bluebunch wheatgrass communities on the drier sites, and shrub steppe communities of rabbitbrush, sagebrush, or antelope bitterbrush on the more mesic sites (Asherin and Claar, 1976). Significant alterations in the quality and quantity of upland habitats have occurred since European settlement. Habitats on more gentle topography have been converted to commercial agriculture, with the remaining areas used as pasture for domestic livestock. Some remnant shrub steppe communities can be found within the Alpowa Creek drainage but these are increasingly threatened by wildfire, and continued livestock grazing. Encroachment of noxious weeds has also degraded the quality of native plant communities within the uplands. Hironaka (1954) described bluebunch wheatgrass and Sandberg’s bluegrass communities that had been invaded by St. John’s wort. Cheatgrass and St. John’s wort were early invaders but now yellow starthistle and other knapweeds are beginning to establish within the drainage. Deadman CreekThe riparian vegetation within this basin was historically more extensive and diverse than what is present today (Black et al. 1997). In most areas, a mixture of mature trees, shrubs, and herbaceous plants covered the entire floodplain. However, as the width of area covered by dense trees and shrubs declined, so did the diversity and abundance of species. The Washington Department of Fish & Wildlife (WDFW) has developed recommendations on the width of the riparian zone that will help maintain high quality fish and wildlife habitat (Riparian Habitat Area-RHA) (Knutson and Naef 1997). Although the recommended RHA for Deadman Creek and its major tributaries is 150 feet, present conditions seldom meet this, contributing to a reduction in large woody debris recruitment potential and the watershed’s ability to support fish and wildlife. A large amount of cropland has been converted into the Conservation Reserve Program (CRP) since 1986. The CRP contract is for ten years and contracts that were signed in 1986 until 1990 have expired and a large portion of these were resigned under newer contracts. Due to the economic conditions of agriculture over the last several years, the enrollment into the government programs continues to increase. The allotment of acres (25%) for CRP in Garfield County will undoubtedly be reached with another CRP signup period, which will set the limit on this type of upland conservation. However, the continuation of the continuous CRP and CREP programs will increase the number of acres along perennial and seasonal streams in the Deadman Watershed. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||