J. Range Manage. 57: 89 -96 January 2004 Recovery of biological crusts following wildfire in Idaho

JULIE H. HILTY, DAVID J. ELDRIDGE, ROGER ROSENTRETER, MARCIA C. WICKLOW- HOWARD, AND MIKE PELLANT

Authors are Botanist, Bureau of Land Management, 400 West F St. Shoshone, Ida., 83352, email: Julie_Hilty @blm.gov; Senior Research Scientist, Department of Land and Water Conservation, c% School of Biological, Earth and Environmental Sciences, University of NSW, Sydney, 2052, NSW, Australia; Botanist, Bureau of Land Management, 1387 S. Vinnell Way, Boise, Ida. 83709; Professor, Biology Department, Boise State University, 1910 University Drive, Boise, Ida. 83725; Great Basin Restoration Initiative Coordinator, Bureau of Land Management, 1387 S. Vinnell Way, Boise, Idaho, 83709. At the time of the research, the senior author was a MSc candidate in the Biology Department, Boise State University, Boise, Ida. Address for correspondence: Bureau of Land Management, 400 West F St. Shoshone, Ida. 83352

Abstract Resumen

Invasion of sagebrush steppe by exotic annual grasses has La invasión de las estepas de "Sagebrush" por zacates anuales modified the structure of shrubland communities over much of exóticos han modificado la estructura de comunidades de mator- the western United States by increasing fuel loads and therefore ral de gran parte del oeste de Estados Unidos al incrementar las the frequency of wildfire. Active revegetation with perennial cargas de combustible, y por lo tanto la frecuencia de fuegos nat- species that encourage the growth of biological soil crusts is criti-urales. La revegetación activa con especies perennes que fomen- cal on many burned sites to prevent dominance by exotic, weedy tan el crecimiento de costras biológicas del suelo es critico en vegetation. However, active regeneration is likely to lead to a dis- muchos sitios quemados para prevenir el dominio de la veg- ruption of the soil surface and impact adversely on soil crustetación exótica de malezas. Sin embargo, es probable que la communities which are important for stability and functioning of regeneración activa conduzca a la disrupción de la superficie del shrub communities. We examined the recovery of biological soil suelo e impacte adversamente las comunidades de la costra del crusts on sagebrush steppe following wildfire. Burning resulted suelo, las cuales son importantes para la estabilidad y fun- in significantly reduced shrub cover and enhanced annual grass cionamiento de las comunidades de arbustos. Examinamos al and annual forb cover compared with unburned sites. Burning recuperación de las costras biológicas del suelo en una estepa de also resulted in substantially reduced diversity and richness of"Sagebrush" después de un fuego no controlado. La quema crust taxa, increased cover of short , but reduced cover ofresultó en una reducción significativa de la cobertura de arbus- and tall mosses growing on the shrub hummocks. Post - tos y aumentó la cobertura de zacates y hierbas anuales en com- fire recovery of perennial grasses and biological soil crusts was paración con los sitios no quemados. La quema también resulto greatest on seeded sites compared with unseeded sites dominateden una diversidad y riqueza de taxas de la costra substancial- by exotic grasses, despite the associated with the mente reducida, incrementó la cobertura de musgos cortos, pero rangeland seeding treatment. Our results indicate that seeding is redujo la cobertura de líquenes y musgos altos que crecen en necessary to facilitate recovery of biological soil crusts and has- arbustos agrupados. La recuperación de los zacates perennes y la ten the development of the perennial component of the shrublandcostra biológica después del fuego fue mayor en los sitios sem- and therefore increase landscape structure. These findings sug- brados en comparación con los sitios no sembrados dominados gest that seeding perennial grasses and resting from livestockpor zacates exóticos, a pesar del disturbio asociado con los reduces exotic annual grasses after fire and benefits tratamiento de siembra del pastizal. Nuestros resultados indican native mosses. que la siembra es necesaria para facilitar la recuperación de la costra biológica del suelo y acelerar el desarrollo del componente perenne del matorral y por lo tanto incrementar la estructura Key Words: cryptogamic crust, microphytic crust, burning, sage- del paisaje. Estos hallazgos sugieren que la siembra de zacates brush, , perennes y el descanso de la vegetación al no apacentar ganado reduce los zacates anuales exóticos después del fuego y beneficia Biological soil crusts (also known as cryptogamic, microbiotic los musgos nativos. or microphytic soil crusts) are complex associations of (mosses and liverworts), lichens, , , and bacteria occurring as a thin layer on and just beneath the soil surface in arid and semi -arid landscapes characteristics and climatic patterns, causing biological crust (West 1990). The relative proportions of different groups of composition to vary considerably between and within geographic organisms comprising biological crusts are influenced by soil regions. Biological crusts are a conspicuous feature of many arid and semi -arid landscapes, fulfilling some of the functions performed We thank Mark Seyfried for advice on study design, Jim Hilty for assistance in the field, Laura Bond and Terry Koen for statistical advice, and Larry St Clair and by vascular plants in more mesic environments. At the most basic three anonymous referees for comments on the manuscript. The study was funded level, many components of biological crusts are photosynthetic by the USDI Bureau of Land Management, Department of Defense Legacy cover, fixing carbon from the atmosphere and sequestering organ- Program, and the Northwest Science Association. USDA Agricultural Research ic carbon into the soil (Beymer and Klopatek 1991). Biological Service, Northwest Watershed Research Center, provided facilities, equipment and technical assistance for soil analyses. crusts bind and stabilize soil surfaces, buffering them from water Manuscript accepted 10 May 03. and wind (Williams et al. 1995, Eldridge 1998, Leys and

JOURNAL OF RANGE MANAGEMENT 57(1) January 2004 89 Eldridge 1998). Many cyanobacteria andponents such as fungal hyphae, algal and Methods all cyanolichens associated with crustscyanobacterial filaments and moss and also fix atmospheric nitrogen, and maylichen rhizines may persist for some time enhance the establishment and survival ofafter burning. This might be responsibleThe study area seedlings by increasing the for reducing erosion on the burned site The study area was located in the availability of essential mineral nutrientswhile the biological crust and vascular Wyoming big sagebrush shrub- steppe com- (Harper and Belnap 2001). Rough crustvegetation begin to recover. However,munity on the Snake River Plain south of Boise, Ida. Three sites, Kuna Butte East surfaces also produce suitable micrositesrepeated burning may completely destroy for , establishment and sur-soil crust structures (Greene et al. 1990). (approximately 4.8 km south of Kuna, Ida, vival of vascular plant seedlings (Lesica Other disturbances, including those 43 °27' N, 116 °26' W, 884 -914 m above sea and Shelly 1992, Harper and Pendletonassociated with restoration methods, can level (asl)), Kuna Butte West (approximate- 1993). Over the past decade land man-also destroy soil crusts. On sites where the ly 4.8 km south of Kuna, Ida., 43 °27'N, agers in some arid and semi -arid regionspotential for exotic annual species inva-116° 27' W, 945 m asl) and Rattlesnake Creek (approximately 4.8 km northeast of have begun to integrate biological crustssion and soil erosion is high, active reveg- into assessments of ecosystem functionetation may be required to avoid irre- Mountain Home, Ida., along U.S. Route 20, 43°10' N, 115 °37' W, 1005 -1035 m asl) and stability (see Rosentreter and Eldridgeversible site degradation after wildfire. In were selected for the study. All sites were 2002). the process of revegetation, seeding with On the Snake River Plain, at the north-rangeland drills may result in fragmenta- located on public lands administered by the Bureau of Land Management (BLM). The ern extent of the Great Basin, these shrub tion, overturning or covering of the bio- steppe communities contain biologicallogical crust, potentially hindering the 3 sites had relatively flat topography and a similar fire history, having been burned crusts dominated by mosses and lichensrecovery of the fire damaged crust. which contribute to an undulating andDisturbance by livestock (Kleiner andextensively and with similar intensities between 1980 and 1983, approximately a pedicelled microtopography in the spaces Harper 1972, Brotherson et al. 1983, decade prior to the commencement of this between perennial plants. Plant communi-Warren and Eldridge 2001) also reduces ties dominated by the shrub Artemisia tri-biological crust cover and increases the study (Kochert and Pellant 1996). Sites that were selected had about a decade of recov- dentata Nutt. ssp. wyomingensis Beetle &potential for soil loss due to wind and Young and perennial caespitose grasseswater erosion. Nutrient and hydrologic ery from burning. are common throughout the Great Basin incycles, surface temperatures, and commu- Each site contained areas of 1) western North America. On sites with lownity structure and function can be irre-unburned, 2) burned and seeded, and 3) burned and unseeded shrub steppe. The levels of livestock or recreational use, bio-versibly altered by soil surface distur- unburned and unseeded (termed 'control') logical crusts may occupy much of the soil bance, resulting in accelerated desertifica- surface that is not covered by vasculartion of semi -arid and arid landscapessites supported Wyoming big sagebrush plants or litter (Rosentreter and Belnap(Rosentreter and Eldridge 2002). with a perennial herbaceous understory dominated primarily by the native species 2001). Crust recovery rates vary, and range Composition and structure of manyfrom 2 -5 years for partial regeneration ofSandberg bluegrass (Poa secunda J. native shrub steppe communities havealgal crusts to up to 200 years or more for Presl.) and bottlebrush squirreltail [Elymus been irreversibly modified by extensivemoss and lichen crusts (Callison et al.elymoides (Raf.) Swezey]. Burned sites and uncontrolled livestock impact since 1985, Johansen 2001). However, the pres-which had been revegetated (termed the late nineteenth and early twentiethence of a crust does not imply complete burned - seeded) were seeded with perenni- al grasses using a rangeland drill during centuries. Grazing related problems haverecovery as some elements in the crust been further complicated by the invasionmay still not have recovered and ecosys-the fall following burning. Adjacent of annual Eurasian weeds (Mack 1981).tem function may still be impaired (J.burned and unseeded (termed ëburned- unseededí) sites were also present. All Annual grasses, primarily Bromus tecto-Belnap personal communication, 2003). sites used in this study showed evidence of rum L. and Taeniatherum caput- medusaeFactors that influence recovery rates historic overgrazing, as indicated by the ssp. asperum L. have increased fine -fuelinclude the type of organisms dominating densities within plant communities, andthe crust, the size and severity of the dis- absence of 2 important perennial grasses for homogenized fuel distribution across theturbance, and the proximity of inoculant this geographic area: bluebunch wheatgrass [Pseudoroegneria spicata (Pursh) A. Love] landscape. Increased wildfire frequencies sources to the disturbed area. Biological and Thurberís needlegrass [Achnatherum have resulted in conversion of much of thecrusts are metabolically active only when Artemisia shrub steppe to annual grass-moist, therefore the timing of thurberianum (Piper) Barkworth]. Following lands which in turn burn at intervals ofevents following the disturbance also burning and seeding, these sites were rested less than 10 years (Whisenant 1990).impacts recovery (Belnap and Eldridge from domestic livestock use. Consequently, soil crusts at these sites 2001). in the area are predominantly In this paper we report on a study com- Aridisols, formed on loess and sedimenta- have been affected by changes in speciesparing the recovery of biological soilry deposits covering basalt lava flows composition, grazing and fire cycles. crusts following wildfire in unburned(Hironaka et al. 1983). The is Burning results in loss of biological Wyoming big sagebrush communities semi -arid, with hot, dry summers and cool, crust cover and biomass with the extent ofwith adjacent burned areas with and with-wet winters. Annual precipitation ranges damage depending on fire intensity, the out post -fire seeding. The objective was to from 178 -305 mm, with less than 35% of frequency of returning, and the nature of examine relationships between recovery ofthe moisture occurring between April and the resulting patchwork mosaic of burned the soil crust community and recovery ofSeptember (Hironaka et al. 1983). Mean and unburned areas (Callison et al. 1985,various attributes of the vascular plantdaily temperatures range from -1° C in Schulten 1985, Greene et al. 1990, Youtie community. January to 24° C in July. In general, bio- et al. 1999, Johansen 2001). Depending on logical soil crusts in the unburned sage- the intensity of fires, biological crust com-

90 JOURNAL OF RANGE MANAGEMENT 57(1) January 2004 brush stands were dominated by crustose, the transects were assigned to a particulartwo -way ANOVA (Clarke 1993). Using a squamulose and fruticose lichens andmorphological group (short moss, tallnumber of random permutations on the Pottiaceous mosses (Kaltenecker et al. moss, squamulose lichen, crustose lichen, similarity matrix, ANOSIM produces a 1999). Mosses formed short turfs in thegelatinous lichen or foliose - fruticose test statistic (Global R) with a significance interspaces with lichens interspersed andlichen). These groups enabled us to use level which we used to determine whether growing on top of the moss. Tall moss data collected directly from the field ratherthe cover of the surfaces varied signifi- (Tortula ruralis (Hedw.) Gaertn. et al.than rely on laboratory -based taxonomy cantly between the 3 treatments. commonly forms thick mats under sage- which is inefficient and often requires brush canopies in this shrub- steppe. In thedestructive sampling (Eldridge and burned sites, crusts were completely Rosentreter 1999). However, each site (-1 Results and Discussion destroyed in all but those sites whichha) was systematically searched and failed to carry a fire because of lower fuelvoucher specimens for all bryophytes andSurface soil characteristics levels. lichens were collected. Across all sites, soils tended to be fine - textured silts and barns with low values of Field sampling Soil sampling electrical conductivity and neutral pH For each combination of the 3 sites by 3 Soil samples were analyzed to deter-(Table 1). Silt levels were significantly treatments (control, burned seeded,mine soil texture, electrical conductivityhigher on the burned seeded plots com- burned - unseeded), we established six, 20 and pH. Twenty soil cores, 50 mm diame-pared with the other plots(F1,51 =4.97, P m transects, resulting in a total of 54 tran-ter by 50 mm deep, were collected at 1-= 0.011), and clay contents were sects for the study. Each treatment areameter intervals along each transect and significantly higher on the burned unseeded was stratified to include a relatively homo- combined to form a composite sample. plots compared with the other plots(F1,51 = geneous stand of vegetation 1 to 2 ha inElectrical conductivity and pH were deter- 5.73, P = 0.006; Table 1). Increased silt lev- area, and transects were randomly (and mined on a 1:1 soil -water extract using 3 els may be due to soil disturbance during permanently) located within the stands. sub - samples per transect. Electrical con- the operation of the drill seeder and the cap- We used the line- intercept methodductivity was determined using a YSIture of silt in the upper layers, or conceiv- (Canfield 1941) to measure the cover ofmodel 35 conductance meter. All readingsably, increased capture of silt in the burned - various plant and soil crust components. A were corrected to 25° C. An Orion modelseeded plots due to grasses and a greater tape was laid along the transect as close to 710A benchtop pH/ISE meter was used tocover of crust. We are unable however to the ground as possible to ensure accurate determine pH. Texture of the < 2 mm frac- explain higher levels of clay on the burned - measurement of ground cover. If the soiltion was determined using the hydrometerunseeded plots. There were no significant surface was dry, all transects were moist- method (Gee and Bauder 1986). differences in electrical conductivity, pH or ened with a spray of water to optimize percentage of sand between the 3 treatments detection of biological crusts. During (P > 0.05; Table 1). Statistical analyses In general, soil properties were highly April and May 1994, the following com- variance ponents were measured along each tran- Two -wayanalysisof variable within all sites, but this variability sect: 1) projected foliage cover (i.e. the(ANOVA) was used to test for differencestended to increase when the soils were projected cover of the canopy) of all vas-in the percent cover of various compo-seeded. Much of the soil variability is cular plant species, 2) cover of the visiblenents between the 3 treatments afterrelated to the inherent landscape structure, elements of biological soil crust, i.e.checking for homogeneity of varianceparticularly between shrub interspace and lichen, moss and liverwort (classified byusing Levene's Test (Minitab 1997). Thedisturbed undisturbed patches (Reid et al. morphological group) but excludingsite variable was treated as a random1999). Patchiness at small spatial scales cyanobacteria, 3) cover of litter, 4) cover effect and treatment as a fixed effect in thecan have pronounced effects on soil physi- of rock, and 5) cover of bare groundbalanced model. Post -hoc comparisons ofcal and chemical properties, particularly (excluding cyanobacteria). Litter wastreatment means were performed usingbetween shrub and interspace patches divided into 2 categories: persistent litterLeast Significant Difference (LSD) tests (Bergkamp 1998). (large twigs and woody debris, deep accu-using Minitab (1997). A matrix comprising presence absence mulations of leaves under shrubs, or layers Vascular plant cover of > 10 mm deep) anddata of each soil crust taxa (by genus and species) by 3 treatments (each with 3 Apart from the obvious loss of shrubs in non persistent litter (small twigs, leaves the burned plots (Table 1), there were and other plant debris scattered on thereplicates) was converted to a similarity matrix using the Bray- Curtis similarityother substantial changes in the structure ground, but not forming a thick continu- and composition of the vascular plant ous mat). Standing (non- detached) litter coefficients contained within the PRIMER community which probably influenced the was included in the assessment of vascular (Version 4) statistical package (Clarke and post -fire recovery of the biological crust. plant cover. Warwick, 1994). This similarity matrix Vascular plants were later combinedwas subjected to non metric Multi Exotic annual grasses, particularly Bromus into the following life form groups forDimensional Scaling (MDS) using one oftectorum, dominated the burned - unseeded plots, while cover in both the burned -seed- analysis: shrubs, perennial grasses, peren-the PRIMER (Version 4) routines to deter- nial forbs, annual grasses (primarily exoticmine whether sites of a particular treat-ed and control plots was sparse. The species), and exotic annual forbs. At the ment were characterized by a unique suite sparse cover of shrubs in the burned -seed- time of field measurements, most nativeof soil crust taxa. Hypothesis tests of dif- ed plots was compensated by the signifi- annual forbs were dead and contributedferences between the 3 groups (control,cantly greater cover of perennial grasses, very little cover. Consequently, they wereburned seeded, burned unseeded), defined particularly Agropyron spp. and Elymus not included in the analyses. a priori, were performed using ANOSIM, spp. (P < 0.001, Table 1). Perennial grass Biological soil crust taxa recorded along which is comparable to a distribution -free clumps are known to create microstructure

JOURNAL OF RANGE MANAGEMENT 57(1) January 2004 91 Table 1. Soil physical characteristics and cover components ( %) for the 3 treatments. SE = stan- tation (Ahti 1982), and fragments are able dard error of the mean. Different letters within a row indicate a significant difference at P < to lodge within relatively moist microsites 0.05. at the edge of shrub canopies and under bunchgrass canopies where it thrives in Attribute Control Burned unseeded Burned - seeded association with short mosses. The moist Mean SE Mean SE Mean SE EC (dSm') environment created by the cheatgrass 0.218 0.01 0.248 0.01 0.248 0.02 canopy, and later the short moss in the pH (water) 6.74a 0.04 6.92a 0.03 6.98a 0.03 % sand 30.7a 0.97 33.58 0.77 35.08 1.82 unseeded treatment, probably created a % silt 62.2a 0.85 57.8" 0.82 57.1" 1.79 favourable environment for Cladonia % clay 7.18 0.41 8.7" 0.24 7.98 0.32 pocillum. Cover ( %) In our study, the cover of the short moss Shrub 30.7a 1.62 0.0" 0.00 0.1" 0.04 group was consistently high across all Perennial grass 13.8a 1.32 4.2a 1.04 36.6" 3.17 treatments (Table 4), and increased signif- Perennial forb 0.28 0.08 0.28 0.17 0.68 0.27 Annual grass 0.18 0.06 59.4" 5.92 1.3a 0.66 icantly with the degree of disturbance, Annual forb 0.08 0.00 36.7" 5.10 0.18 0.67 reaching maximum cover on the burned Bare ground 9.08 1.12 7.38 1.93 28.7" 3.63 seeded plots (F2,45 = 291.3, P < 0.001). Rock 3.98 1.33 3.48 0.89 3.78 1.03 Short mosses such as Funaria hygrometri- Persistent litter 25.38 5.51 67.4" 8.19 11.3a 2.37 ca and Ceratodon purpureus are fire Non - persistent litter13.5a 2.64 7.5" 3.41 12.7a 2.64 Total litter 38.8a 3.34 74.9" increasers which are common on burned 3.59 24.08 2.19 sites, often colonising burned organic material. They are also known to form in the landscape, influencing local micro - species (Fig. 1). Analyses of similaritiesassociations with epiphytic cyanobacteria climate and creating a microclimate con-indicated no effect of either burningand non symbiotic heterotrophic bacteria ducive to biological soil crusts (Longton(Global R = 0.13, P = 0.274) nor seeding which might be important for nitrogen fix- 1992). Reestablishment of perennial grass(Global R = - 0.031, P = 0.488) on theation following fire (During and von clumps and recovery of biological soilcommunity structure of biological crustTooren 1990). Depending on light and crusts occurred together and were correlat- taxa. This lack of a burning or seeding moisture levels, a Nostoc- Ceratodon pur- ed with a reduced cover of the invasiveeffect was probably due to the smallpureus association is capable of nitrogen exotic Bromus tectorum (Table 1). amount of replication (n = 3) and the type fixation rates of 25 -110 ng N g' dry mat- Differences in the vascular plant com-of data collected. Had we collected datater (Vlassak et al. 1973). While this is munity had a major impact on the distribu- on species abundance rather than just pres- lower than that observed for a Nostoc- tion of litter. There were significant differ-ence- absence, there may well have beendominated microbiotic crust community ences in the cover of persistent littersignificant burning and/or seeding effects. (Belnap 2001), the contribution of nitro- across the 3 treatments (P < 0.01), with a gen by a continuous moss cover could be significant in nutrient deprived environ- decline from burned - unseeded (compris- Changes in morphological groups ing mainly dead annual grasses), through ments, particularly after burning. In addi- control (sagebrush stems and leaves) to There was significantly greater totaltion to their role in soil nutrition, short lichen cover on the control plots compared the burned- seeded (burned sagebrush and mosses also play an important role in soil assorted dead bunchgrasses) treatments.with either the burned unseeded or stabilization (Eldridge 1998). Cover of non - persistent litter was veryburned seeded plots (F2,45 = 21.9, P < Predictably, the cover of tall mosses was sparse in all treatments, but significantly0.01).There were also significant differ- greatest on the control plots (34.8 %) and less in the burned-unseeded treatmentences in the cover of the various morpho-least on the 2 burned treatments (mean = logical groups (Table 4). The cover of all (Table 1). 1.5 %; F245 =9.74, P < 0.01, Table 4). morphological groups of lichens was sig- Tortula ruralis the dominant tall moss, is nificantly greater on the control plots com- generally restricted to sheltered microsites Soil crust cover and floristics pared with the other plots (P < 0.01). Thebeneath shrub and grass canopies Both lichen species richness and the fruticose- foliose morphological group was (Rosentreter 1994) where it forms exten- total number of species were greatest onthe most abundant, consisting entirely ofsive mats on the soil surface. Tortula the control (35 species), least on the the fruticose species Aspicilia reptans andruralis is well adapted to periodical and burned - unseeded (5 species) and interme-Aspicilia filiformis and the minute folioseprolonged desiccation (Longton 1988) and diate on the burned - seeded (25 species) species Cladonia pocillum (Table 2).is often dry below shrub canopies during plots (Tables 2 and 3). The number ofThese species are generally slower tomid- summer when the vegetation is also moss species was similar between treat- recolonise burned sites. extremely dry and the chance of wildfires ments with 7, 8, and 5 in the control, The lichens recorded from the openis greatest. Fire intensity is high under burned - seeded and burned unseeded treat- areas of the cheatgrass canopy are speciesshrub canopies, due in part to high fuel ments respectively. Riccia glauca, the which are well- adapted to disturbed envi-loads contributed by dead sagebrush only liverwort collected during the study,ronments. Both Caloplaca tominii andtwigs, as well as litter under the shrubs was found at one of the control sites only. Ochrolechia inaequatula have specialized(Blank et al. 1995) and annual plants Fifteen lichen and 1 liverwort speciesstructures for asexual reproduction whichgrowing on shrub hummocks. were found only at the control sites, and 5 probably enhance their ability to disperse Consequently, the moss is destroyed and lichen and one moss species only at theinto disturbed sites. Cladonia pocillum requires a long time period for recovery to burned - seeded plots (Table 2). The MDSoccurs predominantly in the foliose form full cover levels. Its occupation of moist ordination indicated that, overall, sitesbut occasionally produces fruticose struc- sub canopy microsites probably extends were very similar in their complement oftures. It disperses effectively by fragmen-

92 JOURNAL OF RANGE MANAGEMENT 57(1) January 2004 Table 2. Lichens and bryophytes (mosses and liverworts) found on the 3 treatments; * present, - not recorded. Lichen nomenclature follows Esslinger and Egan (1995), Rosentreter (1998), and McCune et al. (2002). nomenclature follows Anderson et al. (1990).

Species Type Control Burned- Burned- unseeded seeded Bryum argenteum Hedw. Moss * Bryum lisae De Not. Moss * Crossidium aberrans Holz. & Bartr. Moss * Funaria hygrometrica Hedw. Moss * Pterygoneurum ovatum (Hedw.) Dix. Moss * Acarospora schleichen (Ach.) A. Massai. Lichen * Aspicilia terrestris Tomin Lichen * Caloplaca tominii Savicz Lichen * Chromatochlamys muscorum (Fr.) H. Mayrh. & Poelt var. octosporum (Nyl.) Lichen * Cladonia pocillum (Ach.) Grognot Lichen * Sw. Ach. Lichen * Didymodon rigidulus Hedw. Moss * Diploschistes muscorum (Scop.) R. Sant. Lichen * Endocarpon pusillum Hedwig Lichen * Lecanora muralis (Schreber) Rabenh. Lichen * Placynthium squamulosum (Ach.) Breuss Lichen * Psora globifera (Ach.) Massai. Lichen * Tortula ruralis (Hedw.) Gaertn. et al. Moss Amandinea punctata (Hoffm.) Coppins & Scheid. Lichen Arthonia glebosa Tuck. Lichen Aspicilia filiformis Rosentreter Lichen Aspicilia reptans (Looman) Wetmore Lichen Candelariella terrigena Räsänen Lichen Lecidea sp. Ach. Lichen Leptochidium albociliatum (Desmaz.) Choisy Lichen Massalongia carnosa (Dickson) Körber Lichen Ochrolechia inaequatula (Nyl.) Zahlbr. Lichen Physcia dimidiata (Arnold) Nyl. Lichen Psora cerebriformis W. A. Weber Lichen Psora montana Timdal Lichen Psora tuckermanii R. Anderson ex Timdal Lichen Riccia glauca L. Liverwort Leptogium lichenoides (L.) Zahlbr. Lichen Trapeliopsis steppica McCune & Camacho Lichen Polychidium muscicola (Sw.) Gray Lichen Candelaria concolor (Dickson) Stein Lichen Collema coccophorum Tuck. Lichen Physcia magnussonii Frey Lichen Placynthiella uliginosa (Schrader) Coppins & P. James Lichen Thrombium epigaeum (Pers.) Walk. Lichen Ceratodon purpureus (Hedw.) Brid. Moss

the time over which andand phosphorus concentrations present inpart to its prolific spore production and tol- other physiological functions occur. Full post -burn soils (Southorn 1977), buterance of low light levels. recovery of Tortula ruralis is probably declines in abundance due to competition Several of the mosses recorded in the restricted by the absence of the typicallyfor nutrients, water and light (Hoffmancontrol and seeded treatments are catego- umbrella - shaped canopy of the sagebrush. 1966, Longton 1988). The spores ofrized as "colonists" in terms of During's Funaria hygrometrica, an annual mossFunaria hygrometrica can remain viable (1979) life- history strategies (Longton species, was a common component of thefor more than a decade (Hoffman 1970), 1988). Species such as Bryum argenteum soil surface at the burned unneeded plots, and its ability to grow under conditions ofand Ceratodon purpureus are cosmopoli- and along with Ceratodon purpureuslow light enables it to invade disturbedtan and their broad ecological amplitude tends to invade burned sites rapidly after (Young et al. 1987). Consequently,allows them to successfully inhabit envi- fire (Hoffman 1966, Southorn 1977). ItFunaria hygrometrica thrives in annualronments where rainfall is strongly sea- responds rapidly to high nitrate nitrogengrass stands and other disturbed sites due in sonal and annually unpredictable, such as the semi -arid shrub steppe, and occupy Table 3. Mean diversity (no. of species) and richness (Margalef's index) of biological crust taxa on later successional stages in the communi- the 3 treatments. SE = standard error of the mean. Different letters within a row indicate a sig- ty. In this type of environment they might nificant difference at P < 0.05. function as "perennial stayers ", species that occupy stable environments (Longton Control Burned unseeded Burned seeded 1988). Both species are perennial and Mean SE Mean SE Mean SE reproduce from either spores or vegetative Number of species 24.0a 2.6 5.7b 1.5 14.3' 5.1 propagules. Both Bryum argenteum and Richness 7.2a 0.6 2.7h 0.5 5.0` 1.2 Bryum lisae were the dominant mosses in the burned - seeded plots, establishing an

JOURNAL OF RANGE MANAGEMENT 57(1)January 2004 93 germination in the presence of a crust is difficult to determine and most studies are only correlative. Reasons could relate to the a physical barrier to germination or reduced levels of soil -seed contact pro- duced by moss or lichen plants (Jacques 1984), or to allelopathic effects on exotic BU species by organisms in the crust (sensu Zaady et al. 1997) CC It seems likely that the combination of C increased cover of seeded perennial grass- BS es, and increased germination of small mosses responding to increased area of BU BS BS bare soil at the burned - seeded sites is BU responsible for the decrease in annual grasses. Some combination of competition from perennial grasses and the paucity of suitable sites for germination for annual grasses is also likely to have contributed to the reduced cover of annual grasses. stress =0.09 However, the factors directly responsible for enhanced crust cover and reduced cover of annual grasses particularly Bromus tectorum, still needs to be deter- mined by detailed field experiments. Dimension I Fig. 1. The first 2 dimensions of the Non Metric Multi- Dimensional Scaling biplot based on pres- Management implications and ence- absence of species, showing the relative positions of control (C), burned - seeded (BS) and conclusions burned - unseeded (BU) sites. Note the similarity of the control sites in terms of their complement Historically, Artemisia tridentata ssp. of soil crust species. wyomingensis communities have burned at infrequent intervals (approximately every almost continuous cover in some of thecover to germinate (Evans and Young century or greater), resulting in a relatively shrub interspaces. 1970). Studies in the Great Basin and the stable shrubland- dominant plant commu- semi -arid woodlands of eastern Australia nity (Whisenant 1990). Despite the com- Crust and ecosystem recovery have demonstrated that germination ofbined effects of both fire and disturbance Recovery of the biological crust proba-native, awned grasses (Stipa and Aristida) by seeding, some recovery of biological bly influences the succession of the vascu-is unaffected by an intact cryptogamiccrusts did occur in our study area. Our lar plant community following wildfire. crust (Howell 1998, Eldridge and Simpson data suggest that some disturbance of the Success of seed germination in a moss2002). However, once the crust has beencrust during the process of reseeding is layer is partially dependent on morpholog-removed, germination declines, and there preferable to no reseeding, as it provides ical and physiological characteristics ofis a concomitant increase in the germina-greater control of annual grasses and ulti- both the seed and moss colony (Johnson tion of exotic plants. In the western United mately allows the crust to recover in the and Thomas 1978, During and van ToorenStates, cheatgrass germination is sup- absence of annual grasses. Reestablishment 1990, van Tooren 1990). Once germina-pressed by a stable cover of cryptogams,of landscape patchiness, with areas of tion occurs, persistence of the juvenilebut typically increases when the crust is shrubs separated from biological soil crust - plants in the moss mat might be enhanceddisturbed (Larsen 1995, Howell 1998).dominated interspaces is critical for the by additional moisture and reduced tem-The mechanism for this suppression of perature relative to bare ground (Johnson Table 4. Crust cover, lichen cover and cover of individual morphological groups of lichens and and Thomas 1978, van Tooren et al. mosses. SE = standard error of the mean. Different letters within a row indicate a significant dif- 1988). ference at P < 0.05. Native vascular plant species, which co- exist with biological crusts in many arid Control Burned unseeded Burned seeded and semi -arid regions, have adaptations Mean SE Mean SE Mean SE which allow them to survive on a range of Cover ( %) crust surface types from smooth surfaces Total crust covers 66.Oa 2.81 34.8b 6.04 45.8c 4.74 where mucilaginous secretions are advan- Total lichen cover 8.la 0.70 0.01b 0.01 0.8b 0.35 tageous (Zaady et al. 1997) to roughened Short mosses 23.1a 4.12 34.0b 6.25 42.9c 3.14 or cracking surfaces where hairs and Tall mosses 34.8a 1.06 0.8b 0.51 2.1b 1.67 Squamulose lichens 0.6a 0.01 0.0b 0.00 0.0b 0.12 hygroscopic awns are an advantage Crustose lichens 1.8a 0.08 0.0b 0.00 0.2b 0.33 (Eckert et al. 1986). Germination of cheat Gelatinous lichens 1.5a 0.07 0.0b 0.00 0.2b 0.33 grass is known to be inhibited by light Foliose fruticose 4.2a 0.28 0.0b 0.01 0.4b 0.39 (Hulbert 1955), and the large, light- weight lichens seeds require a degree of microrelief or glichen and bryophyte cover only.

94 JOURNAL OF RANGE MANAGEMENT 57(1)January 2004 Clarke, K.R. and R.M. Warwick. 1994. maintenance of key ecosystem processeswhere there is only limited vegetation dis- turbance, wildfire is likely to have a Change in marine communities: an approach such as (Reid et al. 1999), and to statistical analysis and interpretation, provides for shrub obligate speciesreduced impact on biological soil crusts Natural Environment Research Council, UK. ( Yensen et al. 1992). Our observations due to the discontinuity of fuel. Our fieldDuring, H.J. 1979. Life strategies of suggest that these plant -free, relativelyobservations at this and other sites in the bryophytes: a preliminary review. Lindbergia open interspaces are important to the Snake River Plain suggest that sites with 5: 2 -18. recovery of biological soil crusts, particu-an extensive, intact cover of biologicalsoil During, H.J. and B.F. van Tooren. 1990. larly the lichen component, as lichens are crust in the interspaces tend to have a Bryophyte interactions with other plants. Botan. J. Linn. Soc. 104:79 -98. restricted to these interspaces. sparser cover of Bromus tectorum. Future studies of fire, biological soil crusts andEckert, R.E. Jr., F.F. Peterson, M.S. The development of biological soil Meurisse, and J.L. Stephens. 1986. Effects crusts is retarded by both fire and distur- invasion by annual exotic weeds aim to of soil- surface morphology on emergence bance, and their interactions (Kaltenecker explore the links between intact crust sur- and survival of seedlings in big sagebrush et al. 1999). The combination of distur- faces and their impact on the germination communities. J. Range Manage 39: 414 -420. bance (particularly overgrazing) and fireand establishment of exotic plants. Eldridge, D.J. 1998. Trampling of microphytic leads to a dominance by exotic annual crusts on calcareous soils and its impact on grasses, increasing the frequency of range erosion under rainimpacted flow. Catena 33: Literature Cited 221 -239. fires and leading to further reduced levels Eldridge, D.J. and R. Rosentreter. 1999. of crust cover. Invasion by exotic annual Morphological groups: a framework for grasses may permanently alter the biologi- Ahti, T. 1982. Evolutionary trends in cladoni- monitoring microphytic crusts in arid land- cal crust community (Johansen 2001). iform lichens. J. Hattori Botan. Lab. 52: scapes. J. Arid Environ. 41:11 -25. Annual grass invasion increases plant den- 331 -341. Eldridge, D.J. and R. Simpson. 2001. Rabbit sity, reducing spatial heterogeneity in the Anderson, L.E., H.A. Crum, and W.R. Buck. (Oryctolagus cuniculus L.) impacts on vege- shrub steppe community (Mack 1981, 1990. List of the mosses of North America tation and soils, and implications for man- Yensen et al. 1992) and eliminating the north of Mexico. Bryol. 93: 448 -499. agement of wooded rangelands. Basic Appl. Belnap, J. 2001. Factors influencing nitrogen Ecol. 3:19 -29. interspaces (Whisenant 1990), the pre- fixation and nitrogen release in biological Esslinger, T.L. and R.S. Egan. 1995. A sixth ferred habitat for biological crusts and soil crusts. pp. 241 -262. In: J. Belnap and O. checklist of the lichen- forming, licheni- their associated taxa. Lange (eds.) Biological soil crusts: structure, colous, and allied fungi of the continental In our study, recovery of mosses and management and function. Ecological United States and Canada. Bryol. 98: lichens in the unseeded treatments was Studies 150. Springer - Verlag Berlin. 467 -549. limited by accumulation of Bromus tecto- Belnap, J. and D.J. Eldridge. 2001. Evans, R.A. and J.A. Young. 1970. Plant litter rum litter (Table 1), particularly when lit- Disturbance and recovery of biological soil and establishment of alien annual weed crusts. pp. 363 -384. In: J. Belnap and O. ter depth exceeded about 1 cm. Although species in rangeland communities. Weed Sci. Lange (eds.) Biological soil crusts: structure, this litter and annual plant cover provide 18:697 -703. management and function. ecological studies Evans, R.A. and J.A. Young. 1984. Microsite protection to the soil surface, they are 150. Springer Verlag Berlin. requirements for downy brome (Bromus tec- transient and when removed by periodic Bergkamp, G. 1998. A hierarchical view of torum) infestation and control on sagebrush wildfire, surfaces are often exposed to soil the interactions of runoff and infiltration with rangelands. Weed Sci. 32:13 -17. and nutrient loss. This litter also prevents vegetation and microtopography in semiarid Gee, G.W. and J.W. Bauder. 1986. Particle ecosystem recovery by giving exotic shrublands. Catena 33:201 -220. size analysis. pp. 383 -411. In: A. Klute (ed.) grasses such as cheatgrass a competitiveBeymer, R.J. and J.M. Klopatek. 1991. Methods of soil analysis. American Society advantage over native perennial grasses Potential contribution of carbon by micro - of Agronomy, Inc. and Soil Sci. Soc. of phytic crusts in pinyon - juniper woodlands. (Evans and Young 1984, Kaltenecker et Amer. Madison, Wisc. Arid Soil Res. and Rehab. 5:187 -198. Greene, R.S.B., C.J. Chartres, and K.C. al. 1999) further exacerbating the cycle ofBlank, R.R., J.A. Young, and F.L. Allen. Hodgkinson. 1990. The effects of fire on the fire and shrubland collapse. 1995. The soil beneath shrubs before and soil in a degraded semi -arid woodland. I. Revegetation results in a temporary dis- after wildfire: implications for revegetation, Cryptogam cover and physical and micro turbance of the soil surface, which, in pp. 173 -177. In: B.A. Roundy, E.D. morphological properties. Aust. J. Soil Res. degraded sites, is necessary to promote McArthur, J.S. Haley and D.K. Mann 28:755 -777. grass establishment and therefore the (comps.) Proc. wildland shrub and arid land Harper, K.T. and J. Belnap. 2001. The influ- restoration symposium. General Technical ence of biological soil crusts on mineral development of an roughened surface Report INT- GTR -315. USDA Forest Service. (Hilty et al. 2003). Our study has demon- uptake by associated vascular plants. J. Arid Brotherson, J.D., S.R. Rushforth, and J.R. Environ. 47:347 -357. strated that the biological soil crust will Johansen. 1983. Effects of long -term graz- Harper, K.T. and R.L. Pendleton. 1993. recover from disturbance, albeit slowly, ing on cryptogam crust cover in Navajo Cyanobacteria and cyanolichens: can they and perhaps not fully, after range reseed- National Monument, Arizona. J. Range enhance availability of essential minerals for ing. Our field observations of sites in Manage. 35:579 -581. higher plants? Great Basin Nat. 53:59 -72. southern and eastern Idaho indicate thatCallison, J., J.D. Brotherson, and J.E. Hilty, J., D.J. Eldridge, R. Rosentreter, and reseeding is likely to be most effective Brown. 1985. The effects of fire on the M. Wicklow- Howard. 2003. Burning and blackbrush (Coleogyne ramisissima) commu- where post - revegetation impacts such as seeding influence soil surface morphology in nity of southwestern Utah. J. Range Manage. an Artemisia shrubland in southern Idaho. livestock trampling and grazing are mini- 38:535 -538. mal (Tables 3 and 4). Results from fire Arid Land Res. Manage. 17:1 -11. Canfield, R.H. 1941. Application of line inter- Hironaka, M., M.A. Fosberg , and A.H. rehabilitation seedings carried out under ception in sampling range vegetation. J. Winward. 1983. Sagebrush -grass Habitat the Green Stripping program indicate that Forest. 33:388 -394. Types of Southern Idaho. University of Idaho the seeding of grasses provides a degree of Clarke, K.R. 1993. Non - parametric analyses Forest, Wildlife and Range Experiment resilience to repeated fire as well as creat- of changes in community structure. Aust. J. Station Bull. No. 35. University of Idaho, ing a roughened soil surface. In areas Ecol. 18:117 -143. Moscow, Ida.

95 JOURNAL OF RANGE MANAGEMENT 57(1) January 2004 Hoffman, G.R. 1966. Ecological studies ofMinitab 1997. References Manual, ReleaseWilliams, J.D., J.P. Dobrowolski, and N.E. Funaria hygrometrica Hedw. in eastern 10.1, Minitab Inc. State College, Penn. West. 1995. Microphytic crust influence on Washington and northern Idaho. Ecol. Reid, K.D., B.P. Wilcox, D.D. Breshears, and interrill erosion and infiltration capacity. Monogr. 36:157 -180. L. MacDonald. 1999. Runoff and erosion in Trans. ASAE 38:139 -146. Hoffman, G.R. 1970. Spore viability in Funaria a piñon juniper woodland: influence of vege- Yensen, E, Q.L. Quinney, K. Johnson, K. hygrometrica. Bryologist 73:634-635. tation patches. Soil Sci. Soc. Amer. J. 63: Timmerman, and K. Steenhof. 1992. Fire, Howell, W. 1998. Germination and establish- 1869 -1879. vegetation changes and population fluctua- ment of Bromus tectorum L. in relation to Rosentreter, R. 1994. Displacement of rare tions of Townsend's ground squirrels. Amer. cation exchange capacity, seedbed, litter, soil plants by exotic grasses. pp. 170 -175. In: Midl. Nat. 128: 299 -312. cover and water. Unpublished thesis, Prescott S.B. Monsen and S.G. Kitchen (comps.)Young, J.A., R.A. Evans, R.E. Eckert, and College, Prescott, Ariz. Proc. Ecology and management of annual B.L. Kay. 1987. Cheatgrass. Rangelands 9: Hulbert, L.C. 1955. Ecological studies of rangelands. Gen. Tech. Rep. INT- GTR -313, 266 -270. Bromus tectorum. Ecol. Monogr. 25:181 -213. USDA Forest Service. Youtie, B., J. Ponzetti, and D. Salzer. 1999. Jacques, I.D. 1984. Self - revegetation of aRosentreter, R. 1998. Notes on the Aspicilia Fire and herbicides for exotic annual grass sagebrush bunchgrass community after sur- reptans Complex, with descriptions of two control: effects on native plants and microbi- face blading by bulldozer. Unpublished M.S. new species. In: M.G. Glenn, R.C. Harris, R. otic soil organisms. pp. 590 -591. In: D. thesis, Washington State University, Dirig and M. S. Cole (eds.) Lichenologia Eldridge and D. Freudenberger (eds.) People Pullman, Wash. thomsoniana. North American Lichenology and Rangelands: building the future. Proc. of Johansen, J.R. 2001. Impacts of fire on bio- in honor of John Thomson. Ithaca, N.Y. the VI`h Internat. Rangeland Congr., Vol 2. logical soil crusts. pp. 385 -400. In: J. Belnap Rosentreter, R. and J. Belnap. 2001. Townsville, Queensland, Australia. and O. Lange (eds.) Biological soil crusts: Biological soil crusts of North America. pp. Zaady E, Y. Gutterman, and B. Boeken. structure, management and function. ecologi- 31 -50. In: J. Belnap and O. Lange (eds.) 1997. The germination of mucilaginous seeds cal studies 150. Springer Verlag, Berlin. Biological soil crusts: structure, management of Plantago coronopus, Reboudia pinnata Johnson, C.D. and A.G. Thomas. 1978. and function. Ecological studies 150. and Carrichtera annua on cyanobacterial soil Recruitment and survival of seedlings of a Springer Verlag, Berlin. crust from the Negev Desert. Plant and Soil perennial Hieracium species in a patchyRosentreter, R. and D.J. Eldridge. 2002. 190:247 -252. environment. Can. J. Bot. 56: 572 -580. Monitoring biodiversity and ecosystem func- Kleiner, E.F. and K.T. Harper. 1972. tion: grasslands, deserts and steppe. pp. Environment and community organization in 223 -237. In: P.L. Nimis, C. Scheidegger and grasslands of Canyonlands National Park. P.A. Wolseley (eds.) Monitoring with lichens Ecol. 53:299 -309. ñ monitoring lichens. Kluwer, Netherlands. Kaltenecker, J.H., M.C. Wicklow- Howard, Schulten, J.A. 1985. The effects of burning on and R. Rosentreter. 1999. Biological soil the soil lichen community of a sand prairie. crusts in three sagebrush communities recov- Bryologist 88:110 -114. ering from a century of livestock trampling, Southorn, A.L.D. 1977. Bryophyte recoloniza- pp. 222 -226. In: E.D. McArthur, W.K. tion of burnt ground with particular reference Ostler and C.L. Wambolt (comps.) Shrubland to Funaria hygrometrica. II. The nutrient ecotones. RMRS -P -11. USDA Forest requirements of Funaria hygrometrica. J. Service, Rocky Mountain Research Station, Bryol. 9:361 -373. Ogden, Utah. van Tooren, B.F. 1990. Effects of a bryophyte Kochert, M.N. and M. Pellant. 1996. Multiple layer on the emergence of seedlings of chalk use in the Snake River Birds of Prey Area. grasslandspecies.ActaOcologica Rangelands 8: 217 -220. 11:155 -163. Larsen, K.D. 1995. Effects of microbioticvan Tooren, B.F., J. den Hertog, and J. crusts on the germination and establishment Verhaar. 1988. Cover, biomass and nutrient of three range grasses. Unpublished thesis, content of bryophytes in Dutch chalk grass- Boise State University, Boise, Ida. lands. Lindbergia 14:47 -54. Lesica, P. and J.S. Shelly. 1992. Effects ofVlassak, K., E.A. Paul, and R.E. Harris. cryptogamic soil crust on the population 1973. Assessment of biological nitrogen fixa- dynamics of Arabis fecunda (Brassicaceae). tion in grassland and associated sites. Plant Am. Midl. Nat. 128: 53 -60. and Soil 38:637-649. Leys, J.F. and D.J. Eldridge. 1998. Influence Warren, S.D. and D.J. Eldridge. 2001. of cryptogamic crust disturbance to wind ero- Biological soil crusts and livestock in arid sion on sand and loam rangeland soils. Earth regions: are they compatible? pp. 401 -416. Surf. Process. and Landf. 23: 963 -974. In: J. Belnap and O. Lange (eds.) biological Longton, R.E. 1988. Life - history strategies soil crusts: structure, management and func- among bryophytes of arid regions. J. Hattori tion. ecological studies 150. Springer Verlag, Bot. Lab. 64:15 -28. Berlin. Longton, R.E. 1992. The role of bryophytes West, N. E. 1990. Structure and function of and lichens in terrestrial ecosystems, pp. microphytic soil crusts in wildland ecosys- 32 -76. In: J.W. Bates and A.M. Farmer tems of arid and semi -arid regions. Adv. (eds.) Bryophytes and lichens in a changing Ecol. Res. 20:179 -223. environment. Cambridge Press, Oxford. Whisenant, S.G. 1990. Changing fire frequen- Mack, R.N. 1981. Invasion of Bromus tecto- cies on Idahoís Snake River Plains: ecologi- rum L. into western North America: an eco- cal and management implications. pp. 4-10. logicalchronicle.Agro- Ecosystems In: E.D. McArthur, E.M. Romney, S.D. 7:145 -165. Smith and P.T. Tueller (comps.) Proc. McCune, B., F. Camacho, and J. Ponzetti. Symposium on cheatgrass invasion, shrub 2002. Three new species of Trapeliopsis on die -off, and other aspects of shrub biology soil in western North America. Bryologist and management. Gen. Tech. Rep. INT -276. 105:78 -85. USDA Forest Service.

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