|Friday, July 09|
EPIPHYTIC BRYOPHYTE DIVERSITY IN Juglans neotropica PLANTATIONS OF ECUADOR
* Ángel Benítez, UTPL, Ecuador
Jefferson Medina , UTPL
Jorge Déleg , UTPL
Wilson Quizhpe , Universidad Estatal Amazónica
Tropical montane forests are considered biodiversity hotspots, where epiphytic bryophytes are an important component of diversity and functioning of these forests. We evaluated the diversity of bryophytes in secondary forests and plantations of Juglans neotropica. The presence and cover of epiphytic bryophytes was registered in 100 trees. We analyzed the effects of microclimatic factors on bryophyte richness using a generalized linear model (GLM), and the changes in species composition using multivariate analysis. Fifty-five bryophyte species were recorded, of which 42 species in secondary forest and 41 in mixed plantations. At tree level, richness was higher in the mixed plantation of J. neotropica compared to the secondary forests, due to the presence of species adapted to high light conditions, however species composition were negatively affected by the more open canopy in the mixed plantation of J. neotropica. We conclude that shade bryophytes are threatened by deforestation, and J. neotropica plantations do not act as refuge for these species.
Tree-forest composition drives bacterial associations with feather-mosses
* Juanita Carolina Rodríguez Rodríguez, Université du Québec en Abitibi-Témiscamingue (UQAT), Canada
Yves Bergeron, Université du Québec à Montréal (UQAM)
Steven W. Kembel, Université du Québec à Montréal (UQAM)
Nicole J. Fenton, Université du Québec en Abitibi-Témiscamingue (UQAT)
Bryophytes host a variety of bacterial linages in their phyllosphere (leaf surfaces), including N2-fixing cyanobacteria that play a key role in the nitrogen cycle (fixing up to 7 kgNha-1yr-1) in nitrogen-limited boreal forests. Despite the high abundance of bryophytes in boreal coniferous ecosystems, few studies have explored the complete bacterial diversity associated with bryophytes and the factors driving these associations. While moss species identity seems to be the main driver of moss-phyllosphere composition, it has been suggested that certain environmental conditions may also play a role. In order to determine the relative importance of moss-species identity and environmental conditions defined by tree-canopy dominance in determining moss-phyllosphere composition, we quantified changes in microbial communities as a function of moss-species identity (Pleurozium schreberi and Ptilium crista-castrensis) and forest type (Black spruce versus Trembling aspen) in boreal forests of northwest Quebec. Results indicate that forest type was the most important driver of moss-associated bacterial community composition. Also, Cyanobacteria drove this pattern as they were highly abundant in trembling aspen stands and less prevalent in black spruce stands. While the intrinsic physicochemistry of leaves can explain host identity as a driver of moss-phyllosphere associations, moss chemical composition also changes with environmental conditions and individual requirements. The heterogeneous and nutrient-rich aspen understory might influence the moss phyllosphere via abiotic effects, competition and facilitation processes. Considering that boreal forests are increasingly dominated by deciduous trees, due to natural fires, human land uses and climate change, effects on bryophyte phyllosphere could result in changes in ecosystem services.
Off-site impacts of mines on understory plants and moss phyllosphere bacteria in boreal ecosystems: integrating mine stages and habitats
* XIANGBO YIN, Université du Québec en Abitibi-Témiscamingue , Canada
Nicole J. Fenton, Université du Québec en Abitibi-Témiscamingue
Christine Martineau, Laurentian Forestry Centre
Rémi Boisvert, Université du Québec en Abitibi-Témiscamingue
Mining is one of the main anthropogenic disturbances on boreal biodiversity and ecological services in Canada. The off-site ecological impacts of mines are a growing concern with increasing global mining activities over the last decade. This study examined and evaluated the off-site impacts of mines on understory plants and phyllosphere bacterial communities (PBCs) of feather moss (Pleurozium schreberi) with six mines at two stages (operating and non-operating) in Quebec. Six to eight transects were established perpendicularly to each mine’s periphery through different types of ecosystems (forest types and peatlands). Plant and phyllosphere samples were collected inside plots spread along each transect at different distances from each mine’s periphery. We found that: 1) the diversity of plants and PBCs present a significant association with the distance from the edge of mines; 2) Mine stages and ecosystem types present a significant association with the magnitude of off-site impacts of mines. For instance, the relative abundance of Bacteroidetes and Chloroflexi was higher near mines in peatland plots, while no significant impacts were found in non-peatland plots. Non-native plant species were more abundant near operating mines than that of non-operating mines. In conclusion, our results supported the presence of off-site impacts of mines on the diversity and structure of understory plants and phyllosphere bacteria. Furthermore, mine stage and ecosystem type can influence the off-site impacts of mines. These results provide a baseline reference and evidence to guide ecological risk assessments for mining projects considering off-site impacts involved in boreal areas.
Revegetation of disturbed lands: establishing native plant communities on borrow pits in northern Manitoba
* Tess McDonald, University of Manitoba, Canada
Sylvie Renault, University of Manitoba
John Markham, University of Manitoba
The historic occurrence of hydroelectric development in northern Manitoba has resulted in disturbed areas without vegetative cover on ancestral First Nation’s land within the boreal forest. These disturbed areas remain with compacted soil lacking in nutrients, organic matter and possess low water-holding capacities. Northern climate conditions and short growing seasons further inhibit recovery potential. The study objective was to develop a strategy for encouraging self-sustaining native plant communities on borrow pits in northern Manitoba. Using fertilizer and mycorrhizal inoculations, seeding, transplants and cuttings were carried out using locally sourced plant species. Soil nitrogen, phosphorus, organic matter content, pH and electrical conductivity were analyzed for differences among treatments and the surrounding undisturbed forest to determine impacts of material extraction on the land. Plant number, height, leaf-area and chlorophyll fluorescence as a proxy for stress were monitored to assess differences among treatments. Preliminary results of the study show transplantation as the most effective planting method due to extremely low germination rates of seeds and survival of cuttings. Soil nutrients were significantly higher in fertilized treatment plots, although no significant differences were identified in number, size or stress of plants between treatments. This research provides vital information for cost effective site preparation and amendments required for revegetation efforts that can be widely implemented across borrow areas in northern ecosystems. By encouraging a full working ecosystem to develop using local plant species for sustenance and medicinal practices the land will provide more value to the local communities and wildlife populations.
The impacts of rock climbing on lichen and bryophyte cliff communities in northwestern North America
* Giovanna Bishop, Eastern Washington University, United States
Georgia Harrison, University of Idaho
Krisztian Magori, Eastern Washington University
Robin O'Quinn, Eastern Washington University
Jessica Allen, Eastern Washington University
Cliff-dwelling biodiversity is threatened by the increasingly popular sport of rock climbing. In cliff ecosystems lichens and bryophytes are often the most abundant and diverse organisms. Here we report how the popularity, difficulty, and age of rock climbing routes impacts bryophytes and lichens at two different climbing areas in Spokane County, WA, USA (McLellan Rocks and Rocks of Sharon). We compared sixteen rock climbing routes with adjacent unclimbed cliff face for abundance and diversity of lichens and bryophytes from 254, 0.5m2 plots. To control for variation among paired transects across sites we collected slope and rock heterogeneity for each plot, and aspect, and canopy cover per transect. For climbed transects we recorded route age, difficulty, popularity, and approach distance. Linear mixed effect models were used to test how rock climbing impacts lichens and bryophytes. Lichen and bryophyte cover was higher overall in unclimbed transects compared to climbed transects. Route age and plot height explained most of the variation in lichen and bryophyte cover. Older routes had higher lichen but lower bryophyte cover than newer routes. Lichen abundance was directly related to bryophytes at both sites; the lower the bryophyte cover, the higher the lichen cover. New county records and rare species were found across both groups, including the lichens Henrica americana and Umbilicaria vellea and the liverwort Frullania californica. Our results highlight the importance of including route age, climbing intensity, a paired transect study design, and detailed lichen and bryophyte diversity when creating data-driven management plans for rock climbing areas.
Native plant and insect communities along perimeter plantings and interiors of vineyards
* Katarzyna Zgurzynski, Brock University, Canada
Liette Vasseur, Brock University
Niagara Region is home to many vineyards. As monocultures, the way these vineyards are structured and managed can make a big difference to the local biodiversity. In this study, plant and insect species in both organic and conventional vineyards were surveyed within their perimeters and vineyard interiors. Native and invasive plant species were identified, as were beneficial and pest species of insects. Beneficial insects included in the study were some predatory beetles and parasitoid wasps, while pests were aphids, thrips, and leafhoppers. The results showed that more native plants and invasive plants were found in the perimeters of vineyards. Organic vineyards had greater insect abundance overall, but plant species diversity didn’t significantly differ. Native plants and beneficial insects were positively correlated, and there was a slight correlation with native plants and pest insects, as well as overall insect abundance. Other non-native non-invasive plant species were negatively correlated with beneficial insects and insect abundance in general. Invasive plants did not show significant correlation with either groups of insects, though was correlated to insects that were not pests or beneficials. Biological insect control is just one of the ecosystem services that landscapes rich in native plants can provide. These results contribute to a better understanding of how vineyard management, structure, and diversity can impact beneficial insect populations, which can inform sustainable practices within viticulture.
How does larch influence the composition of herbaceous and bryophyte species in the understory?
* Andreane Garant, Université du Québec en Abitibi-Témiscamingue, Canada
Nicole Fenton, Université du Québec en Abitibi-Témiscamingue
Yves Bergeron, Université du Québec en Abitibi-Témiscamingue
High quality litter deposition and low light interception by trees in hardwood stands results in rapid nutrient cycling compared to evergreen conifer stands. This rapid cycling favors the establishment of vascular plants and bryophytes adapted to rich, light environments in the understory. Does tamarack (Larix laricina (Du Roi) K. Koch), a deciduous conifer, have the same impact on understory floristic communities? The objective of this study is to understand the influence of tamarack on the composition of understory vascular plant and bryophyte communities in the boreal forest. Therefore, we studied soil hydrogeochemical characteristics, canopy closure, and the composition and functional traits of understory vascular and bryophyte communities in 19 sites selected to cover a tamarack gradient in Northern Quebec. A total of 10 inventory quadrats were sampled in each site. Our results illustrate a gradient in the composition of understory plants and bryophytes associated with the proportion of tamarack in the canopy. For sites without tamarack, some associated herbaceous species are: Drosera spp., Rhododendron groenlandicum, Kalmia angustifolia, Smilacina trifolia, Kalmia polifolia, Rubus chamaemorus, Chamaedaphne calyculata. For sites with a majority of tamarack (more than 75%), some associated species are: Dryopteris disjuncta, Symphyotrichum cf. ciliolatum, Mitella nuda, Aster radula, Anemone quinquefolia, Pyrola elliptica and Alnus rugosa. We observe that the herbaceous species associated with stands with a lot of tamarack are species of rich and luminous environments compared to the species associated with black spruce stands. In conclusion, tamarack stands have a more rapid cycling of nutrients comparable to hardwood stands.