Each year, the GCC hosts an event in order to bring people together to discuss, and learn about, grasslands and grasslan-related issues in BC. This year, in honour of the GCC's beginnings, we decided to return to the place where the GCC was conceived, namely, Cariboo country and the historical Big Bar Ranch.
Here you will find a summary of the events that took place, including speaker summaries on topics of range management and grassland ecology; photos and maps of the Churn Creek Protected Area. Please browse through the summary and enjoy the Cariboo grasslands and all their splendour. You may wish to download the summary as a PDF package. Educational Summary Package.
This educational summary package includes summaries of the following topics:
Over 80 participants at the Healthy Grasslands Workshop enjoyed a fun weekend full of hands-on learning and interactions with scientists, ranchers, First Nations, government, and general lovers of the grasslands. The speakers informed the participants about a variety of grassland topics while out in the Big Bar area, just west of Clinton. The four day workshop visited Churn Creek Protected area (Empire Valley Ranch), Big Bar Guest ranch and the OK Ranch.
Click here to view the Workshop agenda.
Here is a summary of what occured on this action packed weekend:
Esketemc First Nations and Canoe Creek Band who gave a warm welcome to us once we arrived in the Churn Creek Protected Area. We then broke up into three groups and were informed on topics such as wildlife, soils and vegetation.
Selected Wildlife Topics: from Insects to Bighorn Sheep: Rob Cannings, Ken MacKenzie, Geoff Scudder
There are thousands of species of wildlife in BC's grasslands, but here we examine only a few – Bighorn Sheep, one of Churn Creek’s special mammals, and a selection of insects, a little-known but predominant group of wildlife.
Insects and other terrestrial arthropods in BC are not known as well as we would like. We are frustrated in our inability to tell many ecological stories about them, and thus to discuss grassland health in any detail. We estimate about 30,000 to 35,000 species of insects live in BC, but fewer than half of these are actually recorded. In some poorly studied groups, probably up to 95% of species are unnamed. We estimate there are about 15,000 species of insects at Churn Creek, in all habitats at all elevations.
A serious impediment to the increase of knowledge of insects is the difficulty of species identification. Accurate identifications are critical to good ecological studies. Not only are there myriads of undescribed species, but there are not enough trained taxonomists in North America, or even world-wide, to handle the work.
We can take a quick look at the thousands of insect species by breaking them into a few general functional groups (a few examples seen at Churn Creek are included):
Decomposers and recyclers directly affect soil quality and nutrient availability. The lack of native earthworms in these grasslands means that in many areas arthropods are the main invertebrates turning over the soil underground. Cattle dung is an underutilized resource; up to 80% of its nitrogen is lost into the atmosphere, and therefore there is a significant loss of soil nitrogen if the pats are not rapidly decomposed. Such forms of dung are foreign microhabitats to native insects and in some areas, especially away from places where cattle have concentrated for decades and introduced species are not abundant, cow pats take years to disappear. Some of the main decomposers are dung beetles, and in some western Canadian sites, over 90% of dung beetle individuals in cattle pats are introduced. In all, about 80 species of arthropods have been recorded in cow dung in Canada.
Herbivores, chewing the vegetation or sucking its fluids, are abundant: cicadas, plant bugs, grasshoppers, butterflies and moths are but a few. Bees, many flies and beetles and other insects feed on plant nectar and pollen and pollinate plants, a vital function. Fungal feeders (mites and springtails as well as insects) also occur in vast numbers; the wingless, jumping bristletail (Order Archeognatha), a common inhabitant (but an undescribed species!!), feeds on the algae and bacteria in the cryptogamic crust.
Predators feed on the herbivores and parasitic insects. Robber flies pounce on their prey and inject toxic saliva, then suck up the dissolved tissues. True bugs of various sorts, wasps, ground beetles, ants, spiders and hundreds of other species hunt through the grasslands, above and below the soil surface. Parasitoids such as velvet ants, bee flies and blister beetles (among them the orange Nemognatha clustered on thistle flowers) parasitize the larvae of underground nesting bees. Parasites are everywhere: Warble flies, such as the introduced Hypoderma lineatum, attack cattle and Protocalliphora blowflies infest the nests of bluebirds and swallows.
It is impossible to assess the insect fauna on one visit. The fauna changes with the seasons and differences in activity mean different species are seen at different times of day and in different weather conditions. At a minimum, one needs to use a number of collecting techniques (sweeping and beating vegetation, pitfall trapping, malaise trapping (intercepting flying insects)) at monthly intervals between April and October over two years. It also is useful to have several entomologists involved, because each of us tends to specialize in a particular group and collects accordingly.
Since neither of us (RC, GS) has visited Churn Creek before, and only had a couple of hours collecting on Thursday, our sampling and results are minimal. However, study of both bunchgrass and an adjacent disturbed, weedy depression revealed a diversity of species, some 7 families and about 12 species of true bugs (Heteroptera) in each area. Although the numbers were about the same in the natural and disturbed sites, the species in each were strikingly different. The natural grassland species were typical of this habitat in central BC, many being short-winged or wingless, and with limited ability to disperse. They included both wide-ranging species, typical of western grasslands, but also species confined, in the Fraser River area, to the Lower Grasslands. In contrast, the species in the disturbed area were all fully winged, can readily disperse and are typical of similar disturbed habitats throughout the West.
If one had calculated a diversity index for these two habitats, at least the species richness would have been identical -- yet the species composition is very different. This illustrates the danger of using just numbers of species as an indicator of diversity or habitat health. Furthermore, even in the bunchgrass fauna it is impossible to distinguish healthy grasslands from other conditions, when most of the plant species are present in both. In many herbivorous insect groups, the diversity and nature of the insect fauna is determined by the plant species present.
Alien insect species have already invaded the Protected Area. Examples include the Alfalfa Plant Bug (Adelphocoris lineolatus (Goeze)) on alfalfa along the Empire Valley Road, the Meadow Plant Bug (Leptopterna dolabrata (L.)) on grasses in the damp swales above Dry Lake, and the Meadow Spittlebug (Philaenus spumarius (L.)) on vegetation at Dry Lake.
Bighorn sheep (Ovis canadensis) are one component of healthy grasslands throughout southern British Columbia. Bighorn populations experience periodic all-aged die-offs related to pneumonia-lungworm (Pasteurella-Protostrongylus) infections that may result a in 50% or greater population reduction in the affected herd followed by several years of low lamb recruitment. Bighorn sheep often harbour lungworm parasites and pneumonia bacteria without experiencing ill health, but poor nutrition, overcrowding, harassment by humans, inclement weather and competition have been cited as triggers for die-offs. Ongoing research in the U.S. has revealed another potential cause of all-aged die-offs and the poor recruitment that follows. A selenium deficiency was suspected as the cause of a large die-off in the Whiskey Mountain bighorn sheep population in Wyoming, a conclusion supported by low selenium levels in forage plants. Preliminary results suggest that acid precipitation on summer ranges reduces the redox potential of the soil which results in the conversion of water-soluble selenium to elemental selenium which cannot be absorbed by forage plant species. Nitrates in the precipitation also promote the growth of actinomycete fungi in the soil which also decrease the availability of water soluble selenium. These findings illustrate the interconnectedness of ecological processes that are required for healthy grasslands.
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