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Great Basin Naturalist Volume 52 Number 1 Article 2 5-11-1992 Secondary production estimates of benthic insects in three cold desert streams W. L. Gaines Central Washington University, Ellensburg, Washington C. E. Cushing Pacific Northwest Laboratory, Richland, Washington S. D. Smith Central Washington University, Ellensburg, Washington Follow this and additional works at: https://scholarsarchive.byu.edu/gbn Recommended Citation Gaines, W. L.; Cushing, C. E.; and Smith, S. D. (1992) "Secondary production estimates of benthic insects in three cold desert streams," Great Basin Naturalist: Vol. 52 : No. 1 , Article 2. Available at: https://scholarsarchive.byu.edu/gbn/vol52/iss1/2 This Article is brought to you for free and open access by the Western North American Naturalist Publications at BYU ScholarsArchive. It has been accepted for inclusion in Great Basin Naturalist by an authorized editor of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. Great Basin Naturalist 52(l), 1992, pp. 11-24 SECONDARY PRODUCTION ESTIMATES OF BENTHIC INSECTS IN THREE COLD DESERT STREAMS W L. Gaine/> 2, C. E. Cushing3, and S. D. Smith1 ABS111.ACf.-We studied aquatic insect production in three cold desert streams in southeastern Washington. The Size-Frequency (SF) and PIB methods were used to assess production, which is expressed by taxon, functional group, and trophic level. Dipterans (midges and black f1ies) were the most productive taxa, accounting for 40-70% ofthe total insect production. Production by collectors and detritivores was thegreatestofall functional groups and trophic levels, respectively, in all study streams. Insects with rapid development times and multiple cohorts are vmy important in cold desert streams; they were major L contributors to the total insect production. Total insect production rates in our study streams (14-23 g DW-m-z.yr- ) were greaterthan those found in Deep Creek, Idaho (1.2 g DW-m -2'yr-1), the only other cold desert stream for which production data are available. Our values also were generally greater than published datu for most cold/mesic (3-27 g DW"m"2'yr"1) and humid/mesic (3--2.5 g DW·m-2'yr-1) streams, but lower than in Sonoran Desert Stream:, (>120 g DW'm-2')'1"-1) or New Zealand streams (~40 g DW_m-2'yr"1). Our (lata support the contention of others that production, rather than density or biomass, is the most accurate and meaningful way to assess the role of these organisms in lotic ecosystems. Key words: productivity, benthos, spring-stremTk~, cold desert, funcUunal groups, trophic levels, Diptem., Trichoptem, Coleoptera, f:phemeroptem, Odonata, Plecoptera. Community-level production of insects has mass analysiS and overestimated by numerical been assessed in relatively few stream types, and analysis in a southeastern stream (Benke et a1. of all macroinvertebrates in even fewer_ Partic­ 1984). Waters (1977) states that production is ularly, little is known about secondary produc­ important to understanding ecosystem dynam­ tion in arid region streams, The only studies of ics because it is the means by which energy is secondary production in arid region streams made available to higher trophic levels. that we are aware ofare those ofMinshall et aI. While most secondary production studies (I973) in Deep Creek, Idaho, in the cold desert have focused on one or a few species in a stream province, and Fisher and Gray (1983) and Jack­ (Benke and Wallace 1980, Waters and son and Fisher (1986) in Sycamore Creek, Ari­ Hokenstrom 1980, O'Hop et a1. 1984), more zona, in the hot desert region, recent studies have estimated secondary pro­ Secondary production is the rate of animal duction of the entire macrobenthic fauna tissue elaboration over time regardless of the (Kmeger and Waters 1983, Benke et a1. 1984, fate (e.g., canlivory, emergence) ofthat produc­ Smock et .1. 1985, HUlyn and Wallace 1987). tion (Benke and Wallace 1980). Estimating sec­ Yet to be integrated into community-level anal­ ondary production in a stream provides one yses are the hyporheic fauna, protozoa, and assessment ofthe role ofanimals in the ecosys­ othermicroinvertebrates_ The community-level tem (Benke andWallace 1980) as well as insight approach prOvides a more integrated insight into ecosystem dynamiCS. Estimating only den­ into the ecology of stream ecosystems, sity and biomass, regardless of time, may not The purpose ofthis study was to measure the accurately describe the role oforganisms in the secondary productionofinsects in threestreams stream. For instance, the role of gathering-col­ located in the cold desert phYSiographic prov­ lectorinvertebrates was underestimatedhy bio- ince ofsoutheastern Washington, We emphasize I D"partm"n! of Biological Sciellces, C"mtral Washington Univt<rsity, Ellensburg, Waohington >18926. 21'rcsent address, U,S. Fore~t S"lVi"",. Leavenworth Hanger District, Leavenworth, Washington 9S826. "Environmental Sden()(c~ Department, l'a"ifk N",t!.westL:llx>rato,y, Richland, WlI<hington 99352.. 11 12 GREAT BASIN NATURALIST [Volume 52 T"HLE 1. Physical and chemil~1 characteristics of study rt:acht:s in Douglas Creek, Snively Springs. nnd Rattlesnake Springs, July 19..'3.5 to June:: 19S6. Average AVt':mge Avemge width delxh disch.'lrge Dissolved 02 3 Stream (m) (Ill) (1I1 /s) (mgtL) Douglas Creek 4.0 o.:n 0.6 9.6--14 Snively S~rings 1.3 0.10 0.04 8.6-12 Hl.lulesna c Springs 1.7 0.05 0.05 8.2-10 TABLE 2. Percent sllhstratull1 t)11es in study reaches of Dnllglas Creek, Snively Springs, and Rattlemake Springs, July HJ85 to June 1986. Substratum type Boulder Cobble Pebblt: Crovel SnnUisilt Stream (>256 mOl) (64-225 mm) (16-64 mm) (2-16 mm) «2 mrn; Douglas Creek 21 29 24 16 10 Snively Springs 7 20 25 11 37 Rattlesnake Springs 0 1 7 11 81 that the estimates published here are, in several the upper reaches where flow is pennanent and cases, based on <L'isumptions that we have not affected by irrigation \vithdrawal. Riparian explained (see Methods). Given the choices to vegetation is dominated by water birch (Betula which we could devote the available resources, occidentalis) and peachleaf willow (Salix we chose to produce an estimate oftotal insect amygdaloidRs) . production in these spring-streams rather than Snively SpIings detailed data on a few taxa. We hope future studies will provide data on growth, CPIs, etc., SS is a small spIing-stream located on the u.S. for all tuxa in these spring-streams which we can Department of Energy's Hanford Site, Wash­ then use to refine the initial estimates presented ing~on. It drains an area of approximately 40 here. km-. The lower reaches ofthespring-stream dry up during the summer, leaving about 3.6 km of STUDY SITES perennial flow (Cushing 1988). Riparian vege­ tation is dominated by cattails (Typha latifalia) This shrub-steppe region is characteIized by along tile upper and lower reaches. and willow a climax communityG'Onsisting ofbig sage (Arte­ (Solh sp.) and wild rose (Rosa sp.) along tile misia tridentata) and bluehunch wheatgmss mid-reaches, where it flows through a canyon. (Agropyrrm spicatum). Mean annual precipita­ Watercress (Nasturtium officinale = Rorippa tion in the area is about 14 em. The study nasturtium-aquaticum) grows extensively streams were Douglas Creek (DC). Snively within the spIing-stream. SpIings (SS), and Rattlesnake SpIings (RS) (Fig. Rattlesnake Springs 1). The average width, depth, discharge, and dissolved oxygen concentration for each study RS is a small spring-stream also located on the reac.:h are shown in Table 1. and the substratum Hanford Site. It drains an area of 350 km2 composition is given in Table 2. Figure 2 shows (Cushing et al. 1980). Portions of the lower the daily and seasonal temperature ranges. .reaches dry up during the summer. leaving about 2.5 km of perennial flow. Mean annual Douglas Creek total alkalinity (as CaC03) is 127 ppm, and the DC is a spIing-fed stream located in Douglas spring-stream is subject to periodic severe County, Washington. It is the largest ofthe three spates in winter (Cushing and Wolf 1982, Cush­ strearns studied, the stream itself draining an ing and Gaines 1989). Riparian vegetation is 2 areaof530 km . Our studysites were located in dominated by peachleaf willow and cattails. 1992] 1NSECf PRODUCfMTY IN SPRING-STREAMS 13 Fjg. 1. Study reaches: A, Douglas Creek; B, Snively Springs; C, Rattlesnake Springs. 14 GREAT BASIN NATURALIST [Volume 52 20 ,..--------------",---c-..,.,,---,------, Douglas Creek o Daily High o Daily Low 10 5 2g ~==~='=='==========: Snively Springs ~ ()o 15 ~ 2~~=='==~====:'===='===~ Rattlesnake Springs 20 15 10 J A SON D J FMAM J 1985 1986 Fig. 2. Annual water temperature regimes: Douglas Creek, Snively Springs, and Rattlesnake Springs, July 1985 to June 1986. Watercress is presently the dominant in-stream METHODS autotroph, although periphytou primary pro­ duction exceeded that ofwatercress in 1969-70 We sampled segments of each stream repre­ (Cushing and Wolf 1984). senting the various habitats that were present. 1992J INSECf PRODUCI1Vm IN SPRING-STREAMS 15 One study reach was sampled in SS and one in sources ofinfonnation to estimateCPls for each RS, and three reaches were sampled in the taxon in OUf study streams. First, we surveyed larger DC. Samples were taken to calculate an the available life-history data gathered from lit­ average standing stock for each stream to he erature reviews and estrapoJated the results to used to calculate production estimates. The apply to our situations. Second, we made field 'Mmpling scheme was not designed to allow observations to determine presence/absence of intrastream comparisons of production esti­ taxa and collected size-frequency information mates between different habitats, but rather to for each taxon to estimate larval development provide representative production estimates of times and CPls.

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