Soil Science Society of America Journal 66:1584-1586 (2002)
© 2002 Soil Science Society of America
DIVISION S-5—NOTES
Cicada burrows as indicators of paleosols in the inland pacific northwest
A. T. O'Geen*,a,
P. A. McDaniela and
A. J. Busaccab
a Soil Science Division, Dep. of Plant, Soil & Entomological Sciences, Univ. of Idaho, Moscow, ID 83844-2339
b Dep. of Crop and Soil Sciences, Washington State Univ., Pullman, WA 99164-6420
* Corresponding author (ogee2191{at}uidaho.edu)
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ABSTRACT
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Cicada nymphs (Homoptera: Cicadidae) are soil-dwelling insects that form cylindrical back-filled burrows. These unique burrow features persist in soils for thousands of years and are common in soil descriptions in arid and semiarid regions of the inland Pacific Northwest (PNW). We examined the burrowing depth of live cicada nymphs and found that burrowing is concentrated in the upper 50 cm of soil. This depth may be used to distinguish between contemporary and relict burrows in soil profiles developed in transported parent materials, and can serve as a means of identifying paleosols from observations of burrows at greater depths. We then searched all official soil series descriptions within the USDA-NRCS State Soil Geographic (STATSGO) data base for cicada-burrowed horizons below the active burrowing depth to identify buried paleosols. We suggest that evidence of cicada nymph activity can be used to assess soil–stratigraphic relationships at broad scales in the inland PNW.
Abbreviations: OSDs, official soil series descriptions • PNW, Pacific Northwest
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INTRODUCTION
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SOIL-DWELLING FAUNA perform many important activities such as mounding, mixing, forming voids, back-filling voids, and forming and destroying structural units. These activities influence erosion, nutrient cycling, and the movement of water and air (Hole, 1981). There is widespread evidence of cicada nymph activity in soils of the arid and semiarid regions of the inland PNW (Hugie and Passey, 1963; USDA-NRCS Soil Survey Division, 1998; O'Geen and Busacca, 2001). Relatively little work, however, has focused on the pedologic significance of these features and their implications for better understanding of landscape evolution.
A cicada nymph refers to the immature life stage of Homoptera: Cicadidae. In the inland PNW, cicada nymphs develop below ground for 6 to 9 yr, forming unique cylindrical, back-filled krotovinas that are 1 to 2 cm in diameter. These features exhibit a crescentic-packing pattern in thin section or wind-etched exposures (O'Geen and Busacca, 2001). Cicada burrows were described as cylindrical blocky soil structure in desert soils of the northern Great Basin by Hugie and Passey (1963). Cylindrical blocky structure is seldom used in OSDs in the PNW, even though cicada populations are large (O'Geen, 1998). A variety of other descriptors, however, are used to document cicada activity in OSDs (USDA-NRCS Soil Survey Division, 1998). These include cylindrical nodules, rounded krotovinas, and spheroidal aggregates and durinodes, all of which are approximately 1 to 2 cm in diameter (Table 1).
Documented evidence of cicada activity in pedon descriptions is a useful tool for pedogenesis studies because burrows persist for thousands of years (O'Geen and Busacca, 2001). For example, in deep loess deposits of the PNW, episodes of soil development and intense cicada nymph activity are preserved in late Quaternary paleosols that are interstratified with unaltered loess. Cicada-burrowed paleosols were used to document fluctuations in faunal activity in response to climatic changes of the Quaternary Period (O'Geen and Busacca, 2001).
Little published information exists that describes the biology of cicada nymphs in the PNW. In the Northern Great Basin, cicada nymphs were reported to actively burrow between 20 and 100 cm below the soil surface (Hugie and Passey, 1963). In contrast, in the midwest USA, cicada nymphs were reported to remain stationary between 7 and 36 cm below the surface (Westcott, 1973; White and Strehl, 1978; Maier, 1980; Luken and Kalisz, 1989). Many soils developing in thin loess in the PNW contain cicada-burrowed B and C horizons and are often considered contemporary features. We believe that soil profiles in transported parent materials, especially loess, contain both contemporary and relict cicada burrows and that the depth at which burrows are found in the soil profile can be a useful tool for distinguishing between contemporary and paleohorizons. The objectives of this study are to identify the active burrowing depth of live nymphs in soils with native vegetation and use the maximum burrowing depth as a proxy to estimate from OSDs the regional extent of buried paleosols in soils in the inland PNW.
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Materials and Methods
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We first characterized the burrowing habits of cicada nymphs to identify their active burrowing depth in soils of the inland PNW. We observed the nature of cicada nymph activity in four native vegetation zones: sagebrush steppe [Artemisia tridentata Nutt.-Agropyron spicatum (Pursh)], bunchgrass steppe (Agropyron spicatum-Festuca idahoensis Nutt.), meadow steppe (Festuca-Symphoricarpos-Rosa sp.) interspersed with stands of a ponderosa pine (Pinus ponderosa-Festuca-Symphoricarpos-Rosa sp.), and coniferous forest [Pseudotsuga menziesii (Mirbel) Franco, Abies grandis (Doug.), and Abies lasiocarpa (Hook) Nutt.] on the Columbia Plateau (Daubenmire, 1970; Franklin and Dyrness, 1988). Sagebrush steppe was the only vegetation zone that contained significant populations of cicadas, and hence became the focus of the following procedures. Soils of the sagebrush steppe research sites are Haplocambids and Haploxerolls (Boling et al., 1998).
Four sites having deep loess were selected in areas of sagebrush steppe in the western, central, and southeastern portions of the Columbia Plateau (Table 2). The range in environmental characteristics between the research sites is comparable with that of other arid and semiarid regions of the inland PNW (Table 2). Five pedons randomly spaced within a 1-ha portion of each site were excavated to 100-cm depth to characterize the nature of the burrowing organisms. The active burrowing depth of cicada nymphs was assessed in each soil profile using a 50 by 50 cm square point count apparatus having 2.54-cm grid spacing. A count for a burrow was recorded whenever a burrow was located on a grid intersection. This corresponds to 19 possible intersections per row for every 2.54-cm vertical increment, or 361 possible counts per square grid. Point counts were converted to volume percentage (Van Der Plas and Tobi, 1965). Although the point counts were only performed in Washington state, we observed and collected the same species of cicada nymphs and adults in arid and semiarid regions of Oregon and Idaho (O'Geen, 1998).
Next, we identified the geographic extent of cicada nymph activity, by searching OSDs of all STATSGO soil series in the PNW for evidence of cicada burrows. Because there appears to be no single format for describing cicada burrows, we used several different descriptors as evidence of cicada activity (Table 1). In a few cases it was difficult to determine whether features were actually cicada burrows; in such instances we verified that the size of the features and habitat matched that of cicada nymphs, otherwise the OSD was not considered. Little published information exists describing the distribution of cicada populations in the western USA, so we limited our focus to Washington, Oregon, and Idaho where the genus Okanagana is common and widely distributed (O'Geen, 1998). Two lists were compiled: one that identified all map units containing soil series in which cicada burrows were described and a subset of the first list that identified soil series containing cicada burrows below the active burrowing depth.
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Results and Discussion
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Cicada-burrowed soils are extensive in the inland PNW. The STATSGO data base contains approximately 63 soil series that document evidence of burrowing cicada nymphs in this region (Table 3). The STATSGO map units that contain one or more soil series having evidence of cicada nymphs occupy over 6.3 million ha of land (Table 3). This is a conservative estimate of cicada nymph activity because several soil series with cicada burrows are not represented in the STATSGO data base. In addition, unlike relict cicada burrows, which are dense and often cemented, contemporary burrows are difficult to recognize in soil profiles and can be easily overlooked.
Point counts of cicada burrows indicate that contemporary cicada nymph activity is restricted to the upper 40 cm of soils in the inland PNW. Mean burrow abundance was greatest between 20 and 35 cm in all four sites, and ranged from 10 to 55% burrows by volume. Moreover, burrow abundance decreased to <2% at the 45-cm depth (Fig. 1)
. In addition, out of the 33 live nymphs we encountered, all were within 40 cm of the soil surface including nymphs collected in southern Idaho. These point count data indicate that active cicada burrowing is restricted to the upper 50-cm of soils in the inland PNW across a precipitation range of 150 to 400 mm, suggesting that sort-term climatic variation over 10's to 100's of years has no effect. Therefore, cicada burrows found below the 50-cm active burrowing depth should be considered relict features that indicate buried paleosols. Evidence of polygenesis is preserved in Bk, Bt, Bkm, and Bkqm horizons in loess derived soils of the inland PNW. Relative ages of these horizons vary from 15 x 103 yr in Bk horizons to 1.7 x 106 yr in Bkqm horizons (McDonald and Busacca, 1992; Othberg et al., 1997; Blank et al., 1998; Kemp et al., 1998).
Based on this interpretation, the depth at which cicada burrows are found in soil profiles can be used to recognize the sequential development of buried paleosols and contemporary horizons in aggrading landscapes. Over 80% of the OSDs that describe burrows deep in the soil profile do so with no indication that the horizons in which burrows occur are buried. In addition, over 25% of the OSDs indicate cicada nymph activity in C horizons. Horizons that contain cicada burrows below the 50-cm active burrowing depth represent a period of active pedogenesis followed by burial, and should therefore be identified as B or buried B horizons, not C horizons. Landscape aggradation is gradual in thin loess deposits, and as a result organic matter in buried A horizons has been completely oxidized and transformed into B horizons through profile welding (Busacca, 1989; Blank et al., 1998). Moreover, several studies have identified evidence of polygenesis in thin loess deposits of the eastern Palouse and in central and southwestern Idaho from the presence of tephra within B horizons (Busacca, 1989; Othberg et al., 1997; Blank et al., 1998; Kemp et al., 1998).
We identified soil series in the STATSGO data base that contained evidence of cicada burrows below the 50-cm active burrowing depth as described in OSDs (Fig. 2)
. The STATSGO data base contains 53 soil series that document evidence of burrowing below the 50-cm active burrowing depth (Table 3). This corresponds to approximately 5.2 million ha of map units having one or more soil series with a buried paleosol (Fig. 2, Table 3).
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Fig. 2. STATSGO map units containing one or more soil series that have evidence of cicada nymph activity below 50 cm.
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The vertical distribution of cicada burrows as described in OSDs has significant implications to broad-scale stratigraphy of the inland PNW. Our query of the STATSGO data base identified an expansive biostratigraphic unit that exists across the inland PNW (Fig. 2). We know of no other single morphological feature that can be used so successfully to identify the geographic distribution of relict features in thin loess deposits.
Based on OSDs, cicada burrows are often interpreted as contemporary features with few pedogenic implications. Cicada nymphs only inhabit the upper 50-cm of soils across the Columbia Plateau, and are not present in vegetation zones such as bunchgrass steppe and coniferous forest that receive greater mean annual precipitation (O'Geen and Busacca, 2001). Moreover, observations of live nymphs in southern Idaho verify the same active burrowing depth. Based on these findings we interpret cicada activity as a near-surface pedogenic process whose occurrence is preserved through time in soils of aggrading landscapes. As such, the vertical distribution of cicada burrows in a pedon can be used to help interpret the sequential development of horizons and identify paleosols. Moreover, cicada-burrowed horizons can also be used as a tool for interpreting landscape evolution at broad scales in the inland PNW.
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ACKNOWLEDGMENTS
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The authors gratefully acknowledge the financial support of the National Science Foundation (grant EAR 92 20012).
Received for publication May 4, 2001.
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REFERENCES
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- Blank, R.R., B. Cochran, and M.A. Fosberg. 1998. Duripans of southwestern Idaho: Polygenesis during the Quaternary deduced through micromorphology. Soil Sci. Soc. Am. J. 62:701–709.[Abstract/Free Full Text]
- Boling, M., B. Frazier, and A.J. Busacca. 1998. General soil map of Washington. Dept. of Crop and Soil Sciences, Washington State Univ., Pullman, WA.
- Busacca, A.J. 1989. Long Quaternary record in eastern Washington, USA, interpreted from multiple buried paleosols in loess. Geoderma 45:105–122.
- Daubenmire, R. 1970. Steppe vegetation of Washington. Wash. Agric. Exp. Sta. Tech. Bull. 62. Washington State Univ., Pullman, WA.
- Franklin, J.F., and C.T. Dyrness. 1988. Natural vegetation of Oregon and Washington. Oregon State Univ. Press, Corvallis, OR.
- Hole, F.D. 1981. Effects of animals on soil. Geoderma 25:75–112.
- Hugie, V.K., and H.B. Passey. 1963. Cicadas and their effect upon soil genesis in certain soils in southern Idaho, northern Utah, and northeastern Nevada. Soil Sci. Soc. Am. Proc. 27:78–82.
- Kemp, R.A., P.A. McDaniel, and A.J. Busacca. 1998. Genesis and relationship of macromorphology and micromorphology to contemporary hydrological conditions of a welded Argixeroll from the Palouse in Idaho. Geoderma 83:309–329.
- Luken, J.O., and P.J. Kalisz. 1989. Soil disturbance by the emergence of periodical cicadas. Soil Sci. Soc. Am. J. 53:310–313.[Abstract/Free Full Text]
- Maier, C.T. 1980. A mole's-eye view of seventeen-year periodical cicada nymphs, Magicicada septendecim (Hemiptera: Homoptera: Cicadidae). Entomol. Soc. Am. 73:147–152.
- McDonald, E.V., and A.J. Busacca. 1992. Late Quaternary stratigraphy of loess in the Channeled Scabland and Palouse regions of Washington state. Quaternary Res. 38:141–156.
- O'Geen, A.T. 1998. Faunal paleoecology of late Quaternary paleosols on the Columbia Plateau. M.S. Thesis, Washington State University, Pullman, WA.
- O'Geen, A.T., and A.J. Busacca. 2001. Faunal burrows as indicators of paleo-vegetation in eastern Washington, USA. Paleogeography, Paleoclimatology, Paleoecology 169:23–37.
- Othberg, K.L., P.A. McDaniel, and M.A. Fosberg. 1997. Soil development on a Pleistocene terrace sequence, Boise Valley, Idaho. Northwest Sci. 71:318–329.
- USDA-NRCS Soil Survey Division. 1998. Official soil series descriptions data access [Online]. Available at http://www.statlab.iastate.edu:80/soils/osd (verified 23 Apr. 2002).
- Van Der Plas, L., and A.C. Tobi. 1965. A chart for judging the reliability of point counting results. Am. J. Sci. 263:87–90.[Abstract]
- Westcott, C. 1973. The gardener's bug book. Doubleday and Company, Garden City, NY.
- White, J., and C.E. Strehl. 1978. Xylem feeding by periodical cicada nymphs on tree roots. Ecological Entomol. 3:323–327.
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TOP
ABSTRACT
INTRODUCTION
