
Lysandra A. PyleAlberta Biodiversity Monitoring Institute | ABMI · Biological Sciences
Lysandra A. Pyle
PhD Rangeland and Wildlife Resources
About
16
Publications
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Introduction
Additional affiliations
Education
January 2012 - April 2018
September 2007 - December 2011
Publications
Publications (16)
Seed banks (SB) are a cryptic component of grassland plant community (PC) diversity and are overlooked for their contribution of a significant ecological service in the form of plant propagules that replenish the aboveground plant community with new individuals and thereby aid in recovery following disturbance. SB composition often differs from the...
The first approximation of this guide attempts to summarize the plant communities that are expected to occur on rangelands within Manitoba’s Aspen Parkland and Assiniboine Delta Rangeland Ecoregions. These rangeland ecoregions make up most of the area west of the Manitoba Escarpment, except for some higher elevation rangeland ecoregions. This guide...
Synthesis of plant community data from SW Manitoba's grasslands. Potential reference plant communities are identified for common ecosites. State-and-transition models illustrate potential shifts in communities with disturbance or lack there of.
Presentation
http://www.pcap-sk.org/rsu_docs/documents/pyle-nprrw-2018.pdf
Recent Draft of Guide
https:...
Little information exists on the management and range health (RH) of northern temperate pastures, where health is defined as the ability to sustain ecosystem function. We surveyed 102 pastures for RH and their associated managers during 2012–2013 across central Alberta, Canada. Pastures were generally diverse mixes of introduced grasses and contain...
Local adaptation may facilitate range expansion during invasions, but the mechanisms promoting destructive invasions remain unclear. Cheatgrass ( Bromus tectorum ), native to Eurasia and Africa, has invaded globally, with particularly severe impacts in western North America. We sequenced 307 genotypes and conducted controlled experiments. We found...
Understanding plant invasion is a critical issue in the conservation of native grasslands. Diverse and productive plant communities may inhibit invader establishment via biotic resistance, whereas disturbances may facilitate invasion by weakening resistance. These factors may also interact, yet their combined effects on invasion are unclear. Absint...
Restoration of dryland ecosystems is often limited by low seedling establishment and survival. Defoliation caused by insects and small mammals could be an overlooked cause of seedling mortality. In the sagebrush steppe, we examined the effect of seedling defoliation on the survival of perennial grasses commonly used as restoration materials. Under...
Questions
Does plant composition differ among grasslands having divergent disturbance and management histories? Which vegetation attributes and disturbances specifically influence rangeland health?
Location
Northern temperate pastures in the Central Parkland and adjacent Boreal natural regions of central Alberta, Canada.
Methods
Plant composition...
Precipitation pulses and interpulse dry periods are major drivers of dryland ecosystem function globally, yet how the patterning and timing of precipitation inputs and dry periods influence seedling recruitment in these systems is poorly understood. We conducted two experiments to understand how limited and variable patterns of precipitation inputs...
This data set includes the plant composition of 102 pastures sampled in north-central Alberta, Canada. Sampled pastures were located in the Central Parkland and Dry Mixed-Wood natural subregions, and were largely comprised of introduced species. In this study, we examined the influence of pasture disturbance history on vegetation, soil properties,...
Understanding the ecology and life history of rare species is critical to assessing their conservation status and developing effective management strategies. We examined the habitat and demography of impoverished pinweed (Lechea intermedia var. depauperata), a rare, narrowly endemic post-fire coloniser native to the Athabasca Plain of Canada, using...
Studies examining the influence of disturbance and management history on pasture soils across a large sampling area are uncommon. We report on the soil properties found in 102 northern temperate pastures sampled in central Alberta, Canada, and relate these attributes to ongoing pasture management practices compiled from producer surveys and abovegr...
Impoverished pinweed (Lechea intermedia var. depauperata Hodgdon, Cistaceae) is a narrow endemic restricted to the dry, fire-prone Athabasca Plain in northeastern Alberta and northwestern Saskatchewan, Canada. Little is known about the ecology or life history of the taxon that could be used to inform conservation or management decisions. We investi...
Seed banks (SB) are a cryptic component of grassland plant community (PC) diversity and are overlooked for their contribution of a significant ecological service in the form of plant propagules that replenish the aboveground plant community with new individuals and thereby aid in recovery following disturbance. SB composition often differs from the...
Oil and gas infrastructure negatively impacts ecosystem function, increases habitat fragmentation, increases susceptibility to invasive species, and has been linked to decreases in biologically fixed carbon, productivity, and grazing capacity. In the Northern Great Plains, disturbed sites can exhibit dominance by seeded cool season grasses, native...
Questions
Question (1)
In this case, I have a study where soil properties were characterized for 100+ pastures and we are trying to link diverse pasture management activities to changes in soil characteristics. During a recent review we were asked to use a multivariate approach (PCA or regression trees). As a plant ecologist I am very familiar with multivariate analyses for plant communities, where all values in a matrix (e.g. diversity or cover) are of similar units/scale. However, a multivariate approach for soil was never explored previously due to differences in the scale of soil characteristics (e.g. pH, electrical conductivity, to percent C, N, OM, texture, etc.). Could someone offer some advice on how the matrix of soil variables would be prepared for a multivariate test like PCA? Do you adjust the scale of variables with a transformation or run the test with original values?
Thank you.