Open Prairie Research Articles

The Canadian boreal snow water equivalent band

Satellite and conventional snow water equivalent (SWE) dataseis reveal a well‐defined zone of high winter season SWE (>100 mm) that extends across the northern boreal forest of Canada. SWE coefficient of variation (CV) patterns derived from a monthly averaged (1978–2002) passive microwave derived time series show a high degree of interannual variability across open prairie, southern boreal, and open tundra regions of North America while SWE across the northern boreal forest was highly invariant. The potential existence of a consistent SWE zone resistant to interannual climatic variability over the past 25 years is intriguing in the context of the sensitivity of snow cover to climate variability and change. A ground sampling campaign conceived specifically to evaluate SWE distribution across the northern boreal forest was conducted in northern Manitoba during the 2003–04 winter season. Data from this survey confirmed the SWE gradient across the boreal forest, although satellite‐derived retrievals for the tundra were consistently low. A series of Canadian Regional Climate Model (CRCM) simulations were conducted to identify feedbacks between the atmosphere and land surface for a domain focused on the northern boreal forest. A control simulation produced monthly patterns of SWE distribution that closely matched the passive microwave retrievals. Water budget computations showed the SWE accumulation pattern to be a function of the modelled regional precipitation pattern, and not the result of surface processes such as melt or evaporation/sublimation. Mean monthly patterns of 850‐hPa fronto genesis forcing corresponded closely to the patterns of accumulated SWE suggesting that lower tropospheric frontal activity was responsible for the snowfall events that led directly to the deposition of the northern boreal SWE band. CRCM sensitivity experiments were conducted with perturbed land cover and terrain. Only subtle differences in SWE accumulation and frontogenesis patterns relative to the control run were found when complete grassland cover was prescribed, though removing orography greatly enhanced the magnitude and zonal extent of the SWE band.

Factors Affecting Prairie Settlement: A Case Study of Abernethy, Saskatchewan, in the 1880s

Prairie agricultural settlement in the era of the National Policy has often been viewed as an organic process which rewarded the resourceful settlers, while punishing the unsuitable ones. To test this assumption the paper offers a detailed investigation of settlement in two districts in Saskatchewan. The three areas of analysis were the process of land acquisition, the settlers' performance during the homestead "proving- up" period, and long-term economic performance after the receipt of patent. In terms of land acquisition, both Anglo-Canadian settlers in the Abernethy district and German-speaking settlers at Neudorf chose the available lands nearest the railway. Their selection suggests an initial tendency toward commercial production among both groups. The difference was that Abernethy settlers, who generally arrived in the 1880s, claimed superior lands on the open prairie. While about half of these settlers never "proved-up" their homesteads, those who received their patents showed a fairly high degree of persistence as farmers. A close relationship between the receipt of additional quarter-sections of free grant land and long-term economic success was also observed. The German settlers at nearby Neudorf, who settled in the ¡890s on more marshy and wooded lands, showed a contrary tendency. These settlers were far less likely to cancel their homestead entries, but tended to leave their farms soon after receiving their patents. Studies of the long-term economic performance of settlers in both dis- tricts provide support for the proposition that early arrival, and the acquisition of good, cheap, accessible land were among the most powerful determinants of success in settlement.

Habitat Associations and Population Trends of Two Hawks in an Urbanizing Grassland Region in Colorado

Despite increasing interest in the ecological effects of urbanization, relatively little is known about its effects in grasslands. We examined population trends and habitat associations of two predators, the rough-legged hawk (Buteo lagopus) and the red-tailed hawk (B. jamaicensis), in a rapidly urbanizing grassland region at the western edge of the North American Great Plains. Count data indicate that rough-legged hawk populations declined in the area by nearly 75% between 1971 and 2003, at the same time that numbers of red-tailed hawks more than tripled. These changes were not part of wider regional trends, nor were they buffered by development of an open space system in one of the urbanizing counties. While the human population grew steadily over the 33-year period, hawk numbers did not begin to change significantly until the early 1980s, suggesting landscape threshold responses to development. Rough-legged hawks remaining in the area between 1999 and 2002 avoided human settlements and hunted in places with tracts of treeless grassland. In contrast, red-tailed hawks selected relatively tall perches in trees or on utility poles from which to hunt, in areas closer to buildings and roads than randomly selected plots, and remained abundant in the mosaic of developed and rural agricultural lands. The failure of the grassland open space system to sustain the rough-legged hawk, and other bird species characteristic of treeless open prairie, illustrates the challenges of conserving fauna with apparent hypersensitivity to the three-dimensional habitat complexity that accompanies even modest amounts of development.

The Cajuns of East Texas

Although French contacts with Texas go back 300 years, the first permanent mass settlement by francophones began at the turn of the twentieth century when a class of rural migrant workers spilled across the Sabine River from Louisiana settling the open prairies along the principal transportation routes between Beaumont and Houston. Shortly thereafter, the establishment of oil refineries in the Golden Triangle area attracted other Cajuns. Following a momentary pause during the depression years, migration picked up once again as numerous war related industries developed in the Port Arthur area. Today the primarily urban Cajun population of East Texas is less and less conscious of its ethnic differences with mainstream America. Three different associations have been formed to maintain and promote ethnic identity and the use of French.

NATURAL HISTORY OF THE MASSASAUGA, SISTRURUS CATENATUS EDWARDSII, IN SOUTHEASTERN COLORADO

A BSTRACT Studies of natural history are important for determining baseline information, particularly for species that might be threatened or endangered. We collected 254 (141M:94F:19UNK) massasauga, Sistrurus catenatus edwardsii, from May 1995 through October 1996. The average snoutvent length (SVL 6 SD) for adult males (355 6 45 mm) was not significantly different than the SVL of adult females (364 6 24 mm). Habitat descriptions indicate that the massasauga in Colorado is a semi-arid grassland species that utilizes areas of relatively open shortgrass prairie. Massasaugas were active between 14 and 308C, with an average ambient temperature during activity of 22.1 6 2.58C. The time of observed activity shifted through the season, with primarily diurnal activity during the cooler months (April and late September to October) and primarily early evening activity during the hotter months (May through August). Massasaugas in Colorado gave birth to litters of 5 to 7 young between late August and late September, and reproduction appeared to be biennial. Populations of S. c. edwardsii in Colorado are scattered but population size appeared to be relatively large based on number of captures and low recapture rates, particularly in Lincoln County. However, due to habitat loss and fragmentation resulting from agricultural expansion, these populations might become increasingly threatened in the future.

Oregon Places: "Without a Second's Warning": The Heppner Flood of 1903

Oregon Places BobDenOuden "Wit h 11 iiI a Second's Warning" TheHeppner Floodof1903 ? top a hill in the rolling wheat fields and grazing lands ofMor /-Jk row County lies theHeppner cemetery. A walk through its mani ?jl JL cured lawns and orderly clusters of grave markers reveals much about the community nestled in the narrow valley below. The cemetery's ample room for growth speaks to the town ofHeppner's confidence in its own future.Many of the names inscribed on the family plots are those of town founders and figures important to the history of the area. Numerous plots contain multiple generations of familymembers, a testament to the town's strong roots. At the bottom of the hill, meandering in a lazy arc through the small town of Heppner, flowsWillow Creek. The stream, which sometimes dries up completely by late summer, normally runs ankle deep and up to seven feetwide inmid-June. On the afternoon of June 14, 1903, however, Willow Creek was fed by a tremendous cloudburst rain storm and turned into something quite different. The Heppner Gazette reported: Without a second'swarning, a leaping, foamingwall ofwater, 40 feetinheight, struck Heppner at about 5 o'clock Sunday afternoon, sweeping everythingbefore itand leavingonly death and destruction in its wake.1 As a result, June 14,1903, is a prominent date among the rows of head stones in the cemetery. The date also appears on a three-panel stonemonu ment thatwas dedicated in 2003 tomark the hundredth anniversary of the catastrophe. The monument, which includes a panoramic image of the 108 OHQ vol. 105, no. 1 ? 2004 Oregon Historical Society QHS neg.,OrHi 24345 Floodwaters moved through Heppner, Oregon, on June 14, 1903, destroying the town. The toppledtreesin this photographindicatethe forceof the flood.The PalaceHotel, one of the few buildings not destroyed in the event, stands at the center of the image. destruction wrought by the flood and a list of the names of almost 250 people who died as a result, serves as a quiet reminder ofHeppner's day of tragedy. Heppner is located inOregon's Morrow County where Hinton Creek, Shobe Creek, and Balm Fork merge with themuch largerWillow Creek. Willow Creek flows north for approximately seventy miles from its source in the Blue Mountains to itsconfluence with theColumbia River upstream of the town of Arlington, Oregon. After leaving itsmountainous head waters, the creek enters a narrow valley whose width never exceeds three quarters of a mile ? the kind of landscape often favored by early white settlerswho wanted to ensure that their towns had a reliable water supply. DenOuden, "Without a Second's Warning" 109 Heppner, shown here in 1901,was a booming agricultural shipping center serving north central Oregon. Aside fromtheforested headwaterhighlands,thebulkof the watershed is comprised of strongly undulating, treeless prairies dissected by numerous watercourses.2 This geographic province of north-central Oregon isknown as the Deschutes-Umatilla Plateau, a semiarid region that receives fewer than twenty inches of precipitation in a year. The rains that do occur often come in the form of intense thunderstorms thatdump several inches in less than an hour.3 As early as 1858, cattlemen began foraging their herds in the abundant grasses found along the creek bottoms in the Willow Creek Valley, estab lishing cattle camps that later grew into the valley's first settlements. The 1860s gold rush inOregon's JohnDay country, to the south of Heppner, prompted further economic growth. During this time, the Willow Creek Valley served as an important transportation route from the Columbia River steamship landings to the gold strikes.4 Itwas not until 1869, how ever, that the area's first land claim was established by George W. Stansbury, who built a cabin there.5Many others soon arrived, including some Or no OHQ vol. 105, no. 1 egon Trail pioneers who had made it to the Willamette Valley but longed for the open prairies to the east of the Cascade Range. Others were gold seekers who wished to give up their prospecting lifestyles and settle down inwhat became known as Stansbury Flat.6 In 1873,Henry Heppner and Jackson L. Morrow opened the first merchandise store in town to supply thenew inhabitants who tiredofpacking...

Trends in Blizzards at Selected Locations on the Canadian Prairies

Climate Change is anticipatedto result in alterations in cyclone activity over the northern hemisphere. Cyclones in their passage across the open prairie of western Canada spawn one of the more extreme weather events that occur in that part of the country; blizzards. Numerous studies of individual blizzards are available. The objective of this study of blizzards is to identify trends in their seasonal occurrence, in seasonal blizzard weather element extremes, and discuss the results in the context of climate change. Criteria used in western Canada to define a blizzard event during the period of study were applied to the archive of hourly weather data for locations within the Prairie Ecozone. Blizzard events were extracted for the period 1953–1997 and analyzed for trends in seasonal occurrence. Results of this analysis are presented which illustrate a significant downward trend for weather observing locations in the more westerly part of the prairies. This trend is consistent with results found by others that indicate a decrease in cyclone frequency over western Canada. No significant trend was found in the more central and eastern locations. No significant trend was evident in seasonal extremes of blizzard weather elements at most locations.

Blancan lagomorphs and rodents of the Deer Park assemblages, Meade County, Kansas

A new collection of lagomorphs and rodents from the Deer Park B local fauna (l.f.) of Meade County, Kansas is described and compared with other small mammal assemblages of the Meade Basin, including the underlying Deer Park A l.f. Deer Park A was correctly assigned by Hibbard to the Blancan, bridging the gap between earlier Blancan faunas such as Fox Canyon and the late Blancan Sanders l.f. Recent fieldwork indicates that the Deer Park quarries may lie in the Rexroad Formation, rather than in the Ballard Formation as previously assumed. The geology and extinct mammalian contingent at Deer Park suggest that the lower horizon of Deer Park A was an active spring that gradually turned into a marshy environment during Deer Park B time. The rodents of Deer Park B are indicative of an open prairie ecosystem that might have been somewhat more arid than that of southwestern Kansas today.

BLANCAN LAGOMORPHS AND RODENTS OF THE DEER PARK ASSEMBLAGES, MEADE COUNTY, KANSAS

A new collection of lagomorphs and rodents from the Deer Park B local fauna (l.f.) of Meade County, Kansas is described and compared with other small mammal assemblages of the Meade Basin, including the underlying Deer Park A l.f. Deer Park A was correctly assigned by Hibbard to the Blancan, bridging the gap between earlier Blancan faunas such as Fox Canyon and the late Blancan Sanders l.f. Recent fieldwork indicates that the Deer Park quarries may lie in the Rexroad Formation, rather than in the Ballard Formation as previously assumed. The geology and extinct mammalian contingent at Deer Park suggest that the lower horizon of Deer Park A was an active spring that gradually turned into a marshy environment during Deer Park B time. The rodents of Deer Park B are indicative of an open prairie ecosystem that might have been somewhat more arid than that of southwestern Kansas today.

Early Holocene change in atmospheric circulation in the Northern Great Plains: an upstream view of the 8.2 ka cold event

Elk Lake, in northwestern Minnesota, contains numerous proxy records of climatic and environmental change contained in varved sediments with annual resolution for the last 10,000 years. These proxies show that about 8200 calendar years ago (8.2 cal. ka; 7300 radiocarbon years) Elk Lake went from a well-stratified lake that was wind-protected in a boreal forest to a well-mixed lake in open prairie savanna receiving northwesterly wind-blown dust, probably from the dry floor of Lake Agassiz. This change in climate marks the initiation of the widely recognized mid-Holocene “altithermal” in central North America. The coincidence of this change with the so-called 8.2 cal. ka cold event, recognized in ice-core and other records from the circum-North Atlantic, and thought by some to be caused by catastrophic discharge of freshwater from proglacial lakes Agassiz and Ojibway, suggests that the two “events” might be related. Our interpretation of the Elk Lake proxy records, and of other records from less accurately dated sites, suggests that change in climate over North America was the result of a fundamental change in atmospheric circulation in response to marked changes in the relative proportions of land, water, and, especially, glacial ice in North America during the early Holocene. This change in circulation probably post-dates the final drainage of proglacial lakes along the southern margin of the Laurentide ice sheet, and may have produced a minor perturbation in climate over Greenland that resulted in a brief cold pulse detected in ice cores.

A Historical Perspective and Future Outlook on Landscape Scale Restoration in the Northwest Wisconsin Pine Barrens

AbstractThe concurrent discussions of landscape scale restoration among restoration ecologists, and of historic disturbance pattern as a guideline for forest management among forest scientists, offer a unique opportunity for collaboration between these traditionally separated fields. The objective of this study was to review the environmental history, early restoration projects, and current plans to restore landscape patterns at broader scales in the 450,000 ha northwest Wisconsin Pine Barrens. The Pine Barrens offer an example of a landscape shaped by fire in the past. In northwestern Wisconsin historically the barrens were a mosaic of open prairie, savanna, and pine forests on very poor, sandy soils. The surrounding region of better soils was otherwise heavily forested. Six restoration sites have been managed since the middle of this century using prescribed burns to maintain the open, barrens habitat. However, these sites are not extensive enough to mimic the shifting mosaic of large open patches previously created by fire. Extensive clear‐cuts may be used as a substitute for these large fire patches so that presettlement landscape patterns are more closely approximated in the current landscape. We suggest that such silvicultural treatments can be suitable to restore certain aspects of presettlement landscapes, such as landscape pattern and open habitat for species such as grassland birds. We are aware that the effects of fire and clear‐cuts differ in many aspects and additional management tools, such as prescribed burning after harvesting, may assist in further approximating the effect of natural disturbance. However, the restoration of landscape pattern using clear‐cuts may provide an important context for smaller isolated restoration sites even without the subsequent application of fire, in this formerly more open landscape.

Introduction

Introduction

Comparative age structure of a relict prairie transition forest and indigenous forest in southeastern Ohio, USA

Buffalo Beats, a relict prairie area on ridgetop calcareous clay lens soil in southeastern Ohio, USA, is undergoing succession from open prairie to forest. This study considers the comparative tree age structure and radial growth patterns of Quercus alba within the two neighboring ridge top prairie soil sites and the indigenous ridge top forest. Our objective was to describe and compare the spatial and temporal patterns of forest development within the prairie soil areas and adjacent forest as one method to better understand the historical dynamics of this prairie-forest community. We employed a dendroecological approach to estimate the pith year from cores taken from all prairie trees ≥10 cm dbh, and canopy trees in the adjacent forest. The early centuries of vegetation history on Buffalo Beats remain obscure, but published studies employing the abundance of opaline phytoliths indicate that these clay lens soils have been dominated by forbs over the long-term. Radial growth patterns of Q. alba, two of which date to the late 1600s, suggest that the north prairie (traditionally known as Buffalo Beats) may have been partly wooded over much of the past two centuries. Age distributions of canopy trees on both prairie sites were fundamentally similar. Within the past two centuries, it appears there have been two major episodes of tree invasion onto the areas of clay lens soil. The first episode began around 1850 and continued until about 1890, but tree density remained relatively low and was mainly comprised of Q. alba. A high proportion of these trees now occupy canopy positions. A second, more dramatic episode of tree recruitment began on the prairies around 1910, led by Q. alba, which peaked in the 1930s and included a mixture of six Quercus species. We speculate that this last tree invasion was enabled by reduced fire intensity/frequency in southeastern Ohio. The chronosequence of tree encroachment onto the prairies was not spatially uniform. Rather, some areas were more or less sparsely occupied by trees (mostly Q. alba) that appeared in the latter 1800s. Beneath and among these, and within some (north prairie) or all (south prairie) of the remaining open prairie patches, a mixture of mainly Quercus saplings arose primarily within the 1920s and 1930s. Presently, the wooded portions of the clay lens soils are mostly closed-canopy, dominated by Q. alba, and consist of a range of tree ages and sizes. We found that age distributions of canopy trees on the prairie and adjacent forest were similar, and were probably associated with local forest disturbances such as fire and/or logging. Changes in prairie Q. alba growth trends coincident with the three major tree recruitment periods substantiated the notion of forest disturbances at these times. Q. alba growth trends also suggested that forest encroachment onto at least the outer portions of the prairie may have been the 300 year norm.

Microhabitat Use and Community Structure of Darkling Beetles (Coleoptera: Tenebrionidae) in Shortgrass Prairie: Effects of Season Shrub and Soil Type

-I conducted pitfall-trapping studies from 1992 through 1995 to evaluate the effects of vegetation structure and soil texture on seasonal variation in the distribution, relative abundance and species composition of darkling beetles (Coleoptera: Tenebrionidae) in shrub-dominated areas of shortgrass prairie in N-central Colorado. Numbers of beetles captured in traps placed in shrub, cactus, grass and bare-ground microhabitats were used to assess microhabitat use and diel timing of activity, differences in the relative abundance of beetles between spring and summer and to compare beetle communities on sites with different shrub vegetation and soil types. Beetles were most numerous in summer on all sites, although some species showed peaks of activity in spring. All but two species (Eleodes extricata, E. hispilabris) were captured significantly more often in traps beneath shrubs, underscoring the importance of this microhabitat for thermal cover, food or protection from predators. Further, in shrub-dominated areas, beetles were more nocturnal than had been reported previously for adjacent grasslands, suggesting that shrubs kept temperatures on low-lying areas warmer at night than on open prairie. Fourteen tenebrionid species were captured, and on average, significantly more species were captured beneath shrubs than in other microhabitats. Each site had a suite of five resident species, of which only Eleodes obscura and Embaphion contusum were captured on all sites during all trapping periods. Species richness and beetle abundance, especially of the most common species (Eleodes obscura), were inversely related to shrub cover but were greater in areas with coarsely textured soils. Overall, tenebrionid communities in shrub-dominated areas were similar to those reported for open prairie, but small species tend to predominate in grasslands, perhaps because most refuges are relatively small. The prevalence of larger beetles in areas with sandy soils and large shrubs may be related to the number of suitable refuges, both belowground and in vegetation, as well as the availability of preferred feeding and oviposition sites.

Comparison of the Microclimates of a Small Aspen Grove and Adjacent Prairie in Saskatchewan

The microclimate of a small aspen grove in central Saskatchewan was moni- tored between December 1993 and April 1995 and compared with that of the adjacent prai- rie. Inside the grove solar radiation was reduced to 55% in winter and 23% in summer compared with the open prairie. Daily maximum air temperatures averaged 2.5 C higher in the grove just before leaf-out and 1.5 C lower just before leaf fall; daily minimum tempera- tures averaged ca. 0.4 C lower inside the grove throughout the year. Relative humidity was usually 3-4% higher inside the grove, with daily minima as much as 14% higher during the summer. The aspen grove trapped up to 45 cm of additional snow during the 1st winter, but only 5 cm more during the 2nd winter, when regional snowfall was well below normal. In midsummer the near-surface soil was 6-8 C warmer on the prairie, but by midwinter had become ca. 6 C cooler than in the grove; these differences diminished with depth. The annual range of soil temperature at a depth of 10 cm was 24 C inside the grove compared to 38 C outside. Windspeed inside the grove was reduced to 7% of the external value in summer and to 28% during the winter. Calculated windchill values were 15% lower inside the grove as a result of the reduction in windspeed. The potential importance of aspen groves as wildlife habitat is discussed.

Cover is safe during the day but dangerous at night: the use of vegetation by European wild rabbits

The use of protective cover by prey animals is commonly associated with high predation risk. Rabbits (Oryctolagus cuniculus) in southern Spain use vegetated patches in daylight but open prairie during the night, although predation rates are high during both periods. Hiding under vegetation may be adaptive for rabbits during the day because they suffer predation by visually oriented birds of prey, but may be dangerous during the night, when they are hunted by carnivorous mammals that need cover to stalk. Therefore, the heavily predated Spanish rabbits may leave dense cover in nighttime and exploit the rich prairie food.

From Fish Weir to Waterfall

foothills (Snoqualmie Tribe vs. U.S. 1960:5). This wooded valley was dotted with lakes and prairies that abounded in wild game, fish, marine life, berries, and bulbs. Eighteen villages containing 96 reported longhouses were the home of 4,000 to 5,000 Snoqualmie (Martin 1933:178,187). Snoqualmie Falls, with its spectacular 268-foot waterfall, provided a natural boundary which coincidentally divided the tribe into two ecological zones: wooded riverine and open prairie. Tradition holds that a former fish weir at the present site of the Falls was mysteriously transformed into a towering waterfall on account of personal greed. Corporate development now threatens to bury the Falls as a local electric company seeks to divert additional water for hydroelectric power. Conflict is believed to have created the Falls and now threatens to destroy it. This study notes the significance of Snoqualmie Falls in the mythological, traditional, and contemporary life of the Snoqualmie Indians. Mythologically, the Falls provided the setting for the transformation of the chaos of the primeval world into order. Traditionally, the Falls have been a symbolic boundary between the Lower and Upper Snoqualmie. The Falls provides a place for contemporary Snoqualmie to gather to pray, to meditate, to worship, and to renew their contact with their ancestors and spiritual powers. This study examines the historic and contemporary significance of Snoqualmie Falls to two groups of Snoqualmie Indians-those living within the traditional twenty-five mile radius from the Falls and those who live elsewhere in the state of Washington. Section one reviews the ethnological literature on the Snoqualmie Tribe and relates those data to other literature regarding ethnicity and migration. Section two describes the importance of the Falls in traditional Snoqualmie society. Section three explains the perceived importance of the Falls to the contemporary Snoqualmie Tribe. Section four summarizes the present conflict with the Puget Sound Power and Light Company over the use of the water at the Falls.

Discrimination of a wet snow cover using passive microwave satellite data

Snow-cover monitoring using passive microwave remote sensing methods has been shown to be seriously limited under melt conditions when the snowpack becomes wet. A wet snow indicator has been developed using DMSP SSM/I 37 GHz dual-polarization data for the open prairie region of western Canada. The indicator is used to identify areas of wet snow and discriminate them from areas of snow-free land. Validation and testing efforts have illustrated that the addition of the indicator to the current SSM/I snow water equivalent algorithm provides a more accurate representation of spatial snow coverage throughout the winter season for the open prairie region. The improved spatial and temporal information resulting from the use of the indicator enhances both climatological and hydrological analyses of snow-cover conditions using passive microwave data. Although the wet snow indicator has only been validated for the open prairie region of western Canada, it may also be applicable to other regions of similar terrain and vegetative characteristics. However, in areas of dense vegetation, such as the boreal forest, the performance of the indicator is poor due to the generally low 37 GHz polarization differences of the vegetation cover.

Discrimination of a wet snow cover using passive microwave satellite data

Snow-cover monitoring using passive microwave remote sensing methods has been shown to be seriously limited under melt conditions when the snowpack becomes wet. A wet snow indicator has been developed using DMSP SSM/I 37 GHz dual-polarization data for the open prairie region of western Canada. The indicator is used to identify areas of wet snow and discriminate them from areas of snow-free land. Validation and testing efforts have illustrated that the addition of the indicator to the current SSM/I snow water equivalent algorithm provides a more accurate representation of spatial snow coverage throughout the winter season for the open prairie region. The improved spatial and temporal information resulting from the use of the indicator enhances both climatological and hydrological analyses of snow-cover conditions using passive microwave data. Although the wet snow indicator has only been validated for the open prairie region of western Canada, it may also be applicable to other regions of similar terrain and vegetative characteristics. However, in areas of dense vegetation, such as the boreal forest, the performance of the indicator is poor due to the generally low 37 GHz polarization differences of the vegetation cover.

Soil‐Vegetation Relationships in Franciscan Terrain of Northwestern California

AbstractThis study sought to discover how soil and vegetation patterns are related in the mountains of northwestern California. Soils were compared by vegetation‐epipedon type and drainage class, with elevation as a covariate. Vegetation types were (i) open prairie, (ii) coniferinvaded prairie, (iii) oak woodland, (iv) conifer forest with umbric or mollic epipedon, and (v) conifer forest with ochric epipedon. The level of organic carbon (OC) was similar in the upper 10 cm of mineral soil under all vegetation types, but soils under forest and oak woodland had less cumulative OC and N, and a greater decrease with depth than soils under prairie. Ochric epipedons under forest had wider C/N ratios than umbric and mollic epipedons under other vegetation types. Exchangeable Ca2+ and base saturation decreased with increasing elevation. Exchangeable Ca2+ decreased with depth under oak woodland and forest, and pH decreased with depth under oak woodland. Under prairie, pH increased with depth, and Ca2+ exhibited little change. Soils under prairie and invaded prairie had lower exchangeable K+ in upper horizons than soils under forest or oak woodland. Drainage‐impaired subsoils had higher bulk density, pH, and exchangeable Ca2+ than well‐drained subsoils. Conifer invasion was restricted to well‐drained soils. Except for conifer‐invaded prairie, closely associated soil and vegetation patterns indicated that the vegetation mosaic has persisted for a long time.