Quercus Garryana Research Articles

Change in historic fire disturbance in a Garry oak ( Quercus garryana) meadow and Douglas-fir ( Pseudotsuga menziesii) mosaic, University of Victoria, British Columbia, Canada: A possible link with First Nations and Europeans

We investigated late Holocene vegetation and fire changes on southeast Vancouver Island, British Columbia, through high-resolution analysis of pollen, spores and charcoal contained within a forest soil. Located in the Mystic Vale Endowment lands, University of Victoria campus, the site occurs adjacent to Garry oak ( Quercus garryana) meadows within a Douglas-fir ( Pseudotsuga menziesii) forest regionally influenced by First Nations burning. The age of the sequence is estimated from the occurrence of non-native plantain ( Plantago spp.) pollen, between the early 19th century and the present. Prior to the 1850s, the Mystic Vale supported a Douglas-fir forest with a sword fern ( Polystichum munitum) understory. Low-intensity fires may have burned either at or near the site, but did not destroy the stand. From the time of European settlement (ca. 1850s to 1872) to the early 20th century, Douglas-fir forests with a sword fern understory persisted but with more openings than in the past. Adjacent forests were cleared leading to successional stands of red alder ( Alnus rubra). The site may have supported more grasses near or after 1872 because of adjacent cultivation and the introduction of livestock. Local establishment of Garry oaks at the margin of a field adjacent to the deposition site may have occurred at this time. The strong charcoal signal may be attributable to clearing and local fires of European settlers. Exotic weedy species such as plantain arrived during this time. From about the mid 20th century to the present a closed canopy Douglas-fir forest returned. Pre-European charcoal concentrations were significantly greater than modern-day charcoal concentrations. Peak charcoal concentrations coincided with the onset of European settlement in the area, a period in which land-clearing is thought to have been aided by the use of fire. This study suggests that the observed changes in charcoal concentrations in pre- and post-European contact time may be linked with a switch from aboriginal to European ignition sources. The study provides a historical impetus to consider partially restoring parts of southeast Vancouver Island by re-introducing fire via the application of controlled burns.

Behavioral Assumptions of Conservation Policy: Conserving Oak Habitat on Family‐Forest Land in the Willamette Valley, Oregon

Designing policies that harness the motivations of landowners is essential for conserving threatened habitats on private lands. Our goal was to understand how to apply ethnographic information about family-forest owners to the design of conservation policy for Oregon white oak (Quercus garryana) in the Willamette Valley, Oregon (U.S.A.). We examined owners' knowledge, beliefs, values, and socioeconomic contexts through in-depth individual and focus-group interviews to understand their motivations to conserve oak. We then used Schneider and Ingram's (1990) policy analysis framework to compare owners' motivations to the logic of policy. Owners had complex motivations for conserving oak. Despite this complexity, all 5 categories of policy that Schneider and Ingram describe hold promise. Policies that use symbolism to inspire behavior and policies that build capacity can harness owners' stewardship ethics and moral obligations. Policies that offer tangible rewards can build on owners' utilitarian motives. Policies that permit and prohibit behavior can tap owners' concerns about rule violations. Policies that promote voluntary, collaborative efforts can accommodate owners' need for autonomy and flexibility.

Prediction of Growth and Mortality of Oregon White Oak in the Pacific Northwest

Abstract We developed new equations to predict Oregon white oak (Quercus garryana Dougl. ex Hook.) development within ORGANON, a stand-development model that is widely used in the Pacific Northwest. Tree size, competitive status, crown ratio, and site productivity were statistically significant predictors of growth and mortality. Three scenarios were projected with the new equations, the previous ORGANON model, and the Forest Vegetation Simulator. Compared with the two other models, the new equations predicted greater diameter growth in oak woodland and a greater effect of conifer removal in a conifer-oak stand. The new equations, which are based on considerably more information than previous equations, should give forest managers greater confidence in the ability of ORGANON to estimate the impacts of silvicultural treatments on oaks.

Oak Woodland Restoration: Understory Response to Removal of Encroaching Conifers

Oregon white oak (or Carry oak, Quercusgarryana) woodlands and savannas of the coastal Pacific Northwest are legacies of an anthropogenic fire regime that ended with European settlement in the mid-1 800s. Historically, these oak stands had a sparse overstory and an understory dominated by fire-tolerant grasses and forbs. Post-settlement fire suppression resulted in widespread invasion and subsequent overstory dominance by conifers, causing mortality of shade-intolerant oak trees and shifting understory plant communities to shade-tolerant species. In a study on four southwestern Washington sites, our objective was to determine the effects of overstory conifer removal, primarily Douglas-fir (Pseudotsuga rnenziesii), on microclimate, native and non-native understory cover, and sapling growth. Overstory conifer removal created a warmer, drier understory microclimate during summer months. Conifer removal had little effect on native understory cover during five years post-treatment; however, cover of non-native plants, primarily grasses and woody understory species, increased significantly during the same period. Height growth of Oregon white oak and Douglas-fir saplings exhibited a delayed, but positive, response to overstory conifer removal, although the treatment response of Douglas-fir was 133% greater than that of oak. Increases in non-native understory cover and the rapid growth of young Douglas-fir indicate the importance of pre- and post-treatment understory management to control undesirable plants and promote native species such as Oregon white oak.

British Columbia Vegetation and Climate History with Focus on 6 ka BP

British Columbia Holocene vegetation and climate is reconstructed from pollen records. A coastal Pinus contorta paleobiome developed after glacier retreat under cool and probably dry climate. Cool moist forests involving Picea, Abies, Tsuga spp., and Pinus followed until the early Holocene. Pseudotsuga menziesii arrived and spread in the south 10 000-9000 BP, and Picea sitchensis - Tsuga heterophylla forests developed in the north. T. heterophylla increased 7500-7000 BP, and Cupressaceae expanded 5000-4000 BP. Bogs began to develop and expland. Modern vegetation arose 4000-2000 BP. There were early Holocene grass and Artemisia communities at mid-elevations and pine stands at high elevations in southern interior B.C. Forests expanded downslope and lakes formed 8500-7000 BP. Modern forests arose 4500-4000 BP while lower and upper tree lines declined. In northern B.C. non-arboreal communities preceded middle Holocene Picea forests. Abies, Pinus and Picea mariana predominated at various sites after 4000 BP. At 6000 BP Tsuga heterophylla (south) and Picea sitchensis (north) dominated the coast and islands and Quercus garryana and Pseudotsuga on southeast Vancouver Island, but Thuja plicata was infrequent. Southern Interior Plateau vegetation at 6000 BP was more open than today at middle to lower elevations, whereas forests covered the Northern Interior Plateau. Picea forests occurred in northern B.C. Holocene climate phases were: 1) warm dry "xerothermic" ca. 9500-7000 BP, 2) warm moist "mesothermic" ca. 7000-4500 BP, 3) moderate and moist 4500-0 BP, with increasing moisture 8500-6000 BP and cooling (?increased moisture) 4500-3000 BP. B.Cs Hypsithermal had dry and wet stages; 6000 BP occurred in the warm and wet mesothermic stage.

Developing landscape habitat models for rare amphibians with small geographic ranges: a case study of Siskiyou Mountains salamanders in the western USA

To advance the development of conservation planning for rare species with small geographic ranges, we determined habitat associations of Siskiyou Mountains sala- manders (Plethodon stormi) and developed habitat suitability models at Wne (10 ha), medium (40 ha), and broad (202 ha) spatial scales using available Geographic Information Systems data and logistic regression analysis with an information theoretic approach. Across spatial scales, there was very little support for models with structural habitat fea- tures, such as tree canopy cover and conifer diameter. Model-averaged 95% conWdence intervals for regression coeYcients and associated odds ratios indicated that the occurrence of Siskiyou Mountains salamanders was positively associated with rocky soils and PaciWc madrone (Abutus menziesii) and negatively associated with elevation and white Wr (Abies concolor); these associations were consistent across 3 spatial scales. The occurrence of this species also was positively associated with hardwood density at the medium spatial scale. Odds ratios projected that a 10% decrease in white Wr abundance would increase the odds of salamander occurrence 3.02-4.47 times, depending on spatial scale. We selected the model with rocky soils, white Wr, and Oregon white oak (Quercus garryana) as the best model across 3 spatial scales and created habitat suitability maps for Siskiyou Mountains salamanders by projecting habitat suitability scores across the landscape. Our habitat suitability models and maps are applicable to selection of priority conservation areas for Siskiyou Mountains salamanders, and our approach can be easily adapted to conservation of other rare species in any geographical location.

Dynamic variation in sapwood specific conductivity in six woody species

Our goals were to quantify how non-embolism-inducing pressure gradients influence trunk sapwood specific conductivity (k(s)) and to compare the impacts of constant and varying pressure gradients on k(s) with KCl and H2O as the perfusion solutions. We studied six woody species (three conifers and three angiosperms) which varied in pit membrane structure, pit size and frequency of axial water transport across pits (long versus short conduits). Both stepwise ("steady") and nonlinear continuous ("non-steady") decreases in the pressure gradient led to decreased k(s) in all species but white oak (Quercus garryana Dougl. ex Hook), a ring-porous and long-vesseled angiosperm. In one diffuse-porous angiosperm (red alder, Alnus rubra Bong.) and two conifers (western red cedar, Thuja plicata Donn. ex D. Don, and Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco), k(s) was 10-30% higher under steady pressure gradients than under non-steady pressure gradients, and a decrease in the pressure gradient from 0.15 to 0.01 MPa m(-1) caused a 20-42% decrease in k(s). In another diffuse-porous angiosperm (maple, Acer macrophyllum Pursh) and in a third coniferous species (western hemlock, Tsuga heterophylla (Raf.) Sarg), there was no difference between k(s) measured under steady and non-steady pressure gradients. With the exception of western red cedar, a conifer with simple pit membranes, the differences in k(s) between low and high pressure gradients tended to be lower in the conifers than in the diffuse-porous angiosperms. In Douglas-fir, western red cedar and the diffuse-porous angiosperms, k(s) was higher when measured with KCl than with H2O. In white oak, there were no differences in k(s) whether measured under steady or non-steady pressure gradients, or when xylem was perfused with KCl or H2O. The species differences in the behavior of k(s) suggest that elasticity of the pit membrane was the main factor causing k(s) to be disproportionate to the pressure gradient and to the different pressure regimes. The results imply that, if nonlinearities in pressure-flux relationships are ignored when modeling tree water relations in vivo, large errors will result in the predictions of tree water status and its impact on stomatal control of transpiration and photosynthesis.

Post‐Planting Treatments Increase Growth of Oregon White Oak (Quercus garryana Dougl. ex Hook.) Seedlings

Abstract The extent of Oregon white oak woodland and savanna ecosystems in the U.S. Pacific Northwest has diminished significantly during the past century due to land use changes and fire suppression. Planting Oregon white oak seedlings is often necessary when restoring these plant communities. Our objective was to determine the efficacy of post‐planting treatments for establishing Oregon white oak seedlings on sites characterized by low growing season precipitation and coarse‐textured soils. We evaluated the effects of control of competing vegetation, tree shelters, fertilization, irrigation, and planting date on growth of planted seedlings. Survival was generally high (90%), but growth rate varied substantially among treatments. Plastic mulch increased soil water content and increased annual seedling height growth by an average of 56% relative to one‐time manual removal of competing vegetation. Solid‐walled tree shelters reduced browse damage and increased mean annual height growth compared to mesh shelters and no shelter by averages of 7.5 and 10.9 cm, respectively. Controlled‐release fertilizer applied at planting did not consistently increase seedling growth. Weekly irrigation (3.8 L/seedling) increased first‐year seedling growth only where mulch also was applied. Seedlings planted by late February had greater root growth by summer than those planted in early April. Soil water management was necessary for best seedling growth, and the improved height growth in solid‐walled tree shelters allowed the terminal shoot to grow more quickly above the height of animal browse. Our results indicate effective methods for establishing Oregon white oak seedlings, but these results may also be applicable to establishment of other tree species on similarly droughty sites.

Recovery of nontarget Lepidoptera on Vancouver Island, Canada: One and four years after a gypsy moth eradication program

The gypsy moth (Lymantria dispar) is a destructive defoliator that is not established in British Columbia, Canada, because of successful eradication programs involving the microbial insecticide Bacillus thuringiensis var. kurstaki (Btk). In 1999, three aerial applications of Btk were made over two areas, totaling 12,805 ha, on southern Vancouver Island, Canada. The impacts of these Btk applications on nontarget Lepidoptera were studied from 1999 to 2004 on Garry oak (Quercus garryana) and common snowberry (Symphoricarpos albus). In 1999, lepidopteran larvae were collected from S. albus foliage at 24 urban parks and from Q. garryana foliage at 28 oak-dominated habitats. The initial impacts (i.e., 1999 data) were published previously, and the present paper is a continuation of the same study. We tested two hypotheses: Reductions of nontarget Lepidoptera would be more severe at 12 to 13 months postspray than at one to two months postspray, and recovery would be significant, though not necessarily complete, at four years postspray. The total number of nontarget Lepidoptera on S. albus and Q. garryana was significantly reduced in the treatment sites in each year of the study: the reduction was greatest in 2000. Relative to the reference sites, each of 11 species that were initially reduced by the Btk applications showed an increase in the treatment sites between 2000 and 2003, by which time only four species remained significantly reduced in the treatment sites. The uncommon species were significantly reduced in 1999 and 2000 but not in 2003, indicating that some recovery had occurred. Limitations and economic implications of the present study are discussed.

Release of Oregon White Oak from Overtopping Douglas-fir: Effects on Soil Water and Microclimate

Many former Oregon white oak (Quercus garryana) woodland and savanna stands in the coastal Pacific Northwest have been invaded by Douglas-fir (Pseudotsuga menziesii) during the past century as a result of fire suppression. Douglas-fir overtop and suppress the shade-intolerant oak, causing its eventual mortality. Removal of Douglas-fir is necessary for restoration of these oak ecosystems, but such action will influence belowground and near-ground conditions, affecting residual trees and understory communities. In a three-year study on a glacial outwash soil near Olympia, Washington, we compared soil and microclimate conditions near overtopped and released oak trees to determine how soil water content (SWC), throughfall, soil and air temperature, and vapor pressure deficit (VPD) are affected when oak is released from overtopping Douglas-fir. In each year, volumetric SWC near all trees declined from ~0.25 m3 m−3 to ~0.10 m3 m−3 during the growing season, but this decline was delayed approximately one month i...

Micro-Propagation of White-top Aster, <em>Sericocarpus rigidus</em>, a Threatened Species from the Garry Oak Ecosystem in British Columbia

A study was undertaken to examine the feasibility of using micro-propagation techniques to regenerate White-top Aster (Sericocarpus rigidus), a threatened species native to the Garry Oak ecosystem in coastal British Columbia. Shoot multiplication from explants was compared in three different basal media formulations. The effects of varying IAA (indole-3-acetic acid) and kinetin on shoot production were also investigated using one of the three basal media. Shoot production was most successful on modified MS (Murashige and Skoog) media containing various concentrations of BAP (benzylaminopurine) and GA3 (gibberellic acid), followed by media containing IAA and kinetin at concentrations of 2 mg per litre. Root formation occurred readily on modified MS media with IAA and reduced macronutrient and micronutrient concentrations. The study showed that S. rigidus can be successfully propagated using in vitro shoot multiplication.

The Reliability of Citizen Science: A Case Study of Oregon White Oak Stand Surveys

We trained students (grades 3–10) through classroom presentations to survey an Oregon white oak (Quercus garryana) stand in Washington, USA, and compared their data to those obtained from professionals. In May and July 2002, 607 students and 8 professionals surveyed 59 and 22 50-m transects, respectively. We enumerated oaks and ponderosa pines (Pinus ponderosa), measured diameter at breast height, and rated the crown shape of oaks. Oak diameter at breast height measurements and tree counts were consistent between students and professionals (α = 0.05), but subjective crown assessments and live or dead status differed. Students tended to overreport relatively rare pines and larger oaks relative to professionals. This project provided resource managers with data describing oak diameter at breast height and distribution while educating students about the ecology of local wildlife habitat.

Changes in Oregon white oak (Quercus garryana Dougl. ex Hook.) following release from overtopping conifers

Oregon white oak or Garry oak (Quercus garryana Dougl. ex Hook.) is a shade-intolerant, deciduous species that has been overtopped by conifers during the past century in parts of its range due to an altered disturbance regime. We examined the response of suppressed Oregon white oak trees in western Washington, USA, to three levels of release from overtopping Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco). We treated individual oak trees with either full release from competition, partial (“half”) release from competition, or a stand-level thinning of Douglas-fir not directed toward release (control). Five years after treatment, oak trees had suffered no mortality or windthrow. Stem diameter growth was 194% greater in the full-release treatment relative to the control. Acorn production varied widely by year, but in years of higher production, acorn production was significantly greater in both release treatments than in the control. Frequency of epicormic branch formation was significantly increased for years 1 and 2 by the full release; the greatest response occurred between 2 and 6 m above ground level. The greatest number of epicormic branches formed on trees on which the majority of original limbs had died back prior to treatment. Trees with relatively less crown dieback at the time of treatment generally had greater stem growth and acorn production responses to release treatments. Our findings indicate that these released Oregon white oak trees are beginning to recover after an extended period of suppression.

Mental and Biophysical Terrains of Biodiversity: Conserving Oak on Family Forests

This research explores the mental and biophysical terrains of family forest owners' relationships with biodiversity. We used concept mapping, in-depth unstructured interviews, property mapping, and field observation to explore owners' knowledge, beliefs and management approaches. We conducted our research in one watershed in the Oregon white oak (Quercus garryana) ecotype of western Oregon, an ecotype that is considered at risk. The owners in our sample are knowledgeable about the concept of biodiversity and believe they should steward the biodiversity of their forests through management. However, their notion of biodiversity appears to be quite generic, rather than specific to the oak ecotype in which they own land. Moreover, external economic and social forces encourage them to manage for Douglas fir rather than oak. Extending Schneider and Ingram's (1990) theoretical policy framework to conservation, we propose ways for policy to address these limitations and build on owners' motivations.

Cameraria gaultheriella and C. lobatiella attracted in Canada to (E,Z)-8,10-tetradecadienal, the sex pheromone of the European C. ohridella

AbstractField trapping trials showed that Cameraria gaultheriella Walsingham and C. lobatiella Opler and Davis (Lepidoptera: Gracillariidae) were attracted in significant numbers in British Columbia, Canada, to sticky traps baited with 10 µg of (E,Z)-8,10-tetradecadienal (E8Z10-14Ald), the sex pheromone of the European horse chestnut leafminer, C. ohridella Deschka and Dimic. There was perfect specificity in captures at habitats located only about 8 km apart from each other: C. gaultheriella was captured exclusively at a humid habitat covered by the shrub salal, Gaultheria shallon Pursh (Ericaceae), whereas C. lobatiella was trapped at an arid location with Garry oak trees, Quercus garryana Dougl. (Fagaceae). Seasonal flight patterns of these two Canadian Cameraria species, as monitored by pheromone traps, indicated differences in their respective flight periods. The possibility of additional cryptic components in the respective pheromones of these three Cameraria species attracted to E8Z10-14Ald is discussed.

IN MEMORIAM: STANLEY HELMER ANDERSON, 1939–2005

Stanley Helmer Anderson was born on 6 August 1939 in San Francisco, California. He died peacefully at home with his family in Laramie, Wyoming, on 1 September 2005 after a lengthy illness. His wife Donna preceded him in death in 1999. He is survived by two children, Becky Castano and Greg Anderson, their spouses, and a grandson, Ross Anderson. Stan joined the AOU in 1967, became an Elective Member in 1986, and was elected a Fellow in 1995. Stan's interest in birds began through participation in Boy Scout programs in the San Francisco Bay area when he was 11. He graduated from high school in Burlingame, California, in 1957, and from the University of Redlands with a major in Biology and a minor in Chemistry in 1961. A year of graduate courses in Education and Biology at San Jose State College in California followed. Stan went on to serve as a lieutenant in the U.S. Navy from 1963 to 1966, after which he obtained an M.S. degree at Oregon State University under John A. Wiens, studying The Avifaunal Composition of Oregon White Oak Stands. He continued for a Ph.D. under Wiens, completing his dissertation, Ecological Relationships of Birds in Forests of Western Oregon, in 1970. That same year, Stan joined the faculty at Kenyon College, where he worked until 1975. He served as a Scientist at Oak Ridge Associated Universities from 1975 to 1976, and from 1976 to 1980 as Chief of the Migratory Nongame Bird Section of the U.S. Fish and Wildlife Service at the Patuxent Wildlife Research Center. In 1980 he moved to Laramie, Wyoming, as Leader of the Wyoming Cooperative Fish and Wildlife Research Unit. He served as Unit Leader and Professor of Zoology and Physiology at the University of Wyoming until his death. The breadth and depth of Stan's contributions to science were substantial. Between 1970 and 2005, he authored almost 200 scientific publications that appeared in journals ranging from The Auk and Ecology to the Journal of Wildlife Management. He also authored or co-authored multiple editions of three textbooks that have been used widely in the field of wildlife management, as well as books on the Prairie Falcon and forest and rangeland birds of the United States. Stan was one of the first avian ecologists to study bird-habitat relations using multivariate statistical techniques. Throughout his career, a special interest in habitat selection guided his research and his training of students. In recent years, he focused increasingly on endangered species and made significant contributions to solving problems confronting black-footed ferrets and Greater Sage-Grouse. Stan's influence is reflected not only in his extensive contributions to science but also in the many students he mentored. From 1980 to 2005, Stan advised or co-advised 100 graduate students, including 23 Ph.D. and 77 M.S. students. Many of his students currently serve as management or research biologists with state (21%), federal (22%), or tribal (3%) natural resource agencies. Many others are college or university faculty (15%), or biologists with nongovernmental organizations (14%) or consulting firms (10%). And still others presently work in secondary schools, medicine, city planning, and ranching, with one bringing his wildlife background to the U.S. Secret Service. Stan's care and sense of responsibility for his students were evident. He frequently mentioned that mentoring his students was the most rewarding aspect of

Isozyme variation and the conservation genetics of Garry oak

Garry oak ( Quercus garryana Dougl. ex Hook) has a long north–south distribution along the inland Pacific coast. In British Columbia, it is a keystone species in a unique and endangered “Garry oak meadow” ecosystem. Here, we apply isozyme markers to address issues in the conservation and phylogeography of Garry oak. Among 42 populations and 23 gene loci, gene diversity (expected heterozygosity) averaged 0.17, and number of alleles per locus averaged 1.84. These values are about one-half of those found in other white oak species. Using progeny arrays, we found outcrossing rates in two Vancouver Island populations to average 0.96, with no detectable biparental inbreeding; also inbreeding coefficients of the 42 populations averaged near zero (0.025); thus inbreeding is not a significant concern. Cluster analysis of genetic distances identified two major groups of populations: southern Washington – Oregon and Vancouver Island – Gulf Islands; populations within the island region were particularly homogenous. An isolated mainland British Columbia population near Sumas, British Columbia, perhaps of anthropogenic origin, showed the least genetic variability and greatest genetic distance. Generally, geographically isolated populations were more genetically depauperate, which may place handicaps on their survival, but also more genetically distinct, providing a greater evolutionary legacy to the species.

Application of network theory to potential mycorrhizal networks

The concept of a common mycorrhizal network implies that the arrangement of plants and mycorrhizal fungi in a community shares properties with other networks. A network is a system of nodes connected by links. Here we apply network theory to mycorrhizas to determine whether the architecture of a potential common mycorrhizal network is random or scale-free. We analyzed mycorrhizal data from an oak woodland from two perspectives: the phytocentric view using trees as nodes and fungi as links and the mycocentric view using fungi as nodes and trees as links. From the phytocentric perspective, the distribution of potential mycorrhizal links, as measured by the number of ectomycorrhizal morphotypes on trees of Quercus garryana, was random with a short tail, implying that all the individuals of this species are more or less equal in linking to fungi in a potential network. From the mycocentric perspective, however, the distribution of plant links to fungi was scale-free, suggesting that certain fungus species may act as hubs with frequent connections to the network. Parallels exist between social networks and mycorrhizas that suggest future lines of study on mycorrhizal networks.

Size and Shape Differences in Genitalia of Males from Sympatric and Reproductively Isolated Populations of <I>Anthocoris antevolens</I> White (Heteroptera: Anthocoridae) in the Yakima Valley, Washington

Anthocoris antevolens White (Heteroptera: Anthocoridae) is a widespread predatory bug in North America commonly associated with deciduous trees and shrubs. Unpublished observations showed that there is considerable geographic variation in male genitalia in this species and that the variation may lead to reproductive isolation among geographically separated populations. We show that male bugs from two sympatric populations in the Yakima Valley, Washington, one occurring on oak (Quercus garryana Douglas) and the other collected from willow (Salix sp.), differed in size and shape of the phallus and clasper. Mating trials showed that males from the oak source successfully inseminated females from the oak source in 75% of pairings; insemination success for males from the willow source paired with females from the willow source was somewhat lower at 62%. In nonlike crosses (oak × willow, willow × oak), males failed to inseminate the female in 100% of pairings, despite vigorous mating attempts by the males. Copulation duration was independent of population source. However, males from the willow source initiated copulation attempts significantly sooner in the assay than males from the oak source, irrespective of female source. We interrupted copulating pairs by freezing them with liquid nitrogen and showed that males in nonlike crosses generally had failed to fully inflate the phallus in the female. Results support statements made elsewhere that A. antevolens is actually composed of an unknown number of reproductively isolated cryptic species.

Insect Visitation to Wildflowers in the Endangered Garry Oak, <em>Quercus garryana</em>, Ecosystem of British Columbia

The Garry Oak Ecosystem (GOE) is a fragmented and endangered ecosystem in Canada, and is currently the focus of conservation and restoration efforts in British Columbia. However, little is known about the basic biology of GOE forbs, or their relationships with pollinating insects. We monitored wildflowers and their insect visitors in 25 quadrats within a 25 × 25 metre plot, located in a fragment of the GOE near Duncan, British Columbia, for six weeks (the majority of the flowering period). Overall, 21 native and non-native forb species flowered in our quadrats during the survey, and we observed an additional six forb species flowering outside of our quadrats. Eight forbs were visited within quadrats by a total of 13 insect taxa, identified to morphospecies. Visits by eight additional morphospecies were observed outside of the quadrats. In general, visitation was low; however, most insect morphospecies were observed visiting more than one plant species, and most plant species were visited by more than one insect morphospecies, suggesting that pollination may be generalised in this community. A Chi-squared analysis indicated that insect visitation was not proportional to the relative abundance of forbs, with higher than expected visitation to Common camas (Camassia quamash), and no observed visits to 11 species, most with very small (putatively unattractive) flowers. The most frequent insect visitor was the introduced Honeybee, Apis mellifera, followed by native mason bees (Osmia spp.) and mining bees (Andrena spp.). Our observations provide baseline data for future, detailed studies that should investigate the importance of plant-pollinator mutualisms for sustainability of populations and communities in this rare ecosystem.