Disturbance Ecology

Understorey vegetation response to wildfire severity and salvage-logging in the southern Quebec boreal forest (2004)

by Mark Purdon

Full Reference:
Purdon, M., Brais, S., and Bergeron, Y. (2004) Understorey vegetation response to wildfire severity and salvage-logging in the southern Quebec boreal forest. Applied Vegetation Science, 7: 49-60.

In this study we compared the effects of fire on understorey vegetation in the Québec southern boreal forest with... more In this study we compared the effects of fire on understorey vegetation in the Québec southern boreal forest with effects of salvage-logging (clear-cutting after fire). All 61 400-m2 sampling sites were controlled for overstorey composition (Deciduous, Mixed and Coniferous) and disturbance type, which consisted of three fire impact severity (FIS) classes (Light, Moderate and Extreme) and two harvesting techniques (Stem-only and Whole-tree Harvesting). Percent-cover data of vegetation and post-disturbance environmental characteristics were recorded in the field during the first two years after fire as well as soil texture. Ordination of fire alone demonstrated that, on Coniferous sites, fire initiates a succession whereby the understorey Coniferous sites approaches that of Deciduous-Mixed sites, due to the release of the understorey from Sphagnum spp. dominance, this pattern being a function of FIS. On Deciduous-Mixed stands, increased FIS resulted in a transition from herb to shrub dominance. Ordination of all five disturbance types showed that the impact of salvage-logging on understorey composition was within the range of fire, but marginalized to the extreme end of the FIS spectrum. Variance partitioning demonstrated that overstorey and soil texture were the most important explanatory variables of fire alone, while disturbance type explained the largest independent fraction of understorey variation when salvage-logging was introduced. Salvage-logging also results in significant reductions in understorey abundance, richness and diversity, while indicator species analysis suggests that it favours mesoxerophytic to xeric species. Results are interpreted in light of shade-tolerance dynamics, forest floor disturbance and soil moisture regimes. Implications for sustainable forest management are discussed.

The Impact of Salvage-logging after Wildfire in the Boreal Forest: Lessons from the Abitibi (2002)

by Mark Purdon

Full Reference:
Purdon, M., Noël, J., Nappi, A., Drapeau, P., Harvey, B., Brais, S., Bergeron, Y., Gauthier, S., Greene, D. (2002) L’impact des coupes de récupération après feu en forêt boréale: leçons d’Abitibi. Rouyn-Noranda, QC : Chaire industrielle CRSNG-UQAT-UQÀM en aménagement forestier durable. 

French Version: http://web2.uqat.ca/cafd/publication/pub_pdf/fichetech4f.pdf

Effects of recreational rock climbing and environmental variation on a sandstone cliff-face lichen community

by Matthew Adams

Botany, 10.1139/b11-109

Lichen community composition was evaluated for both lichen cover and richness on a cliff face commonly used for... more Lichen community composition was evaluated for both lichen cover and richness on a cliff face commonly used for recreational rock climbing. The sandstone outcrop is located on the Sibley Peninsula, which extends from the north shore of Lake Superior. One-hundred and twenty plots were examined. Each plot was 1 m2 in size, with 60 plots located on unclimbed cliff sections and 60 more located where recreational rock climbing regularly occurs. Lichen richness and cover were significantly lower on the rock climbing sections compared with unclimbed sections. Linear regression models indicated significant relationships with cover and richness to environmental response variables and climbing treatment. Detrended correspondence analysis indicated a separation of lichen community groups on this cliff, and major separations occurred between plots in each climbing treatment. Canonical correspondence analysis indicated a significant amount of community group variation between climbed and unclimbed locations related to climbing treatment and aspect of the plots. Climbing is found to have an impact on this sandstone cliff-face lichen community.

PATCH DYNAMICS OF HYDROLOGICALLY DISTINCT REFUGIA: RECOLONIZATION OF BENTHIC MACROINVERTEBRATES AFTER A RECORD DROUGHT IN A SPRING-FED SEMI-ARID LANDSCAPE

by Rosemary Burk

Published online at: https://www.benthos.org/Other-Publications/NABStracts/2010/7389.aspx

Authors: Burk, Rosemary A. and J. H. Kennedy

This study examines the role of spring-fed refugia during a supraseasonal drought and recolonization of benthic... more This study examines the role of spring-fed refugia during a supraseasonal drought and recolonization of benthic macroinveretebrates in Ash and Silver Creeks (Parker County: TX) over eighteen months. Ash Creek maintained flow for 2.0 km in contrast to other regional streams with minimal surface water and no flow. Recolonization at a downstream intermittent site was slow, compared to rates reported for other prairie streams, with taxonomic richness approaching the headwater site’s eight months post flow. Riffles, perennial and shaded disconnected pools were refugia for drought-sensitive aquatic insects and taxonomic richness by macrohabitat type was significantly different (ANOVA, F3,44=27.34, p<0.0001). SNK analysis demonstrated preferential invertebrate use of refugia grouping macrohabitats as: Riffles>Perennial pools = Shaded disconnected pools > Full sun disconnected pools. Rare relict taxa with low resilience, such as Lutrochus sp., Mayatrichia sp., and Neotrichia sp., would likely be displaced without lotic refugia. Conservation of groundwater is critical to preserving a spatial and temporal patchwork of refugia for benthic invertebrates that increases these variable ecosystems resilience to disturbances and is thought to maintain regional species diversity.

Adapting to global environmental change in Patagonia: What role for disturbance ecology?

by Andrés Holz

Plant diversity and tree responses following contrasting disturbances in boreal forest

by Duane Peltzer

Tree growth and mortality after small-group harvesting in New Zealand old-growth Nothofagus forests

by Duane Peltzer

Effects of time-since-fire on bird species: how informative are generalized fire-response curves for conservation management

by Dale Nimmo

Co-authored with Watson, S.J., Taylor, R.S., Kelly, L.T., Haslem, A., Clarke, M.F. & Bennett, A.F.
Published in Ecological Applications

Modelling natural disturbances in forest ecosystems: a review

by Paulo Fernandes

Published in Ecological Modelling, co-authored with Rupert Seidl, Teresa Fonseca, François Gillete, Anna Jönsson, Katarína Merganičová, Sigrid Netherer, Alexander Arpaci, Jean-Daniel Bontemps, Harald Bugmann, Jose González-Olabarria, Petra Lasch, Céline Meredieu, Francisco Moreira, Mart-Jan Schelhaas and Frits Mohren

Natural disturbances play a key role in ecosystem dynamics and are important factors for sustainable forest ecosystem... more Natural disturbances play a key role in ecosystem dynamics and are important factors for sustainable forest ecosystem management. Quantitative models are frequently employed to tackle the complexities associated with disturbance processes. Here we review the wide variety of approaches to modelling natural disturbances in forest ecosystems, addressing the full spectrum of disturbance modelling from single events to integrated disturbance regimes. We applied a general, process-based framework founded in disturbance ecology to analyze modelling approaches for drought, wind, forest fires, insect pests and ungulate browsing. Modelling approaches were reviewed by disturbance agent and mechanism, and a set of general disturbance modelling concepts was deduced. We found that although the number of disturbance modelling approaches emerging over the last 15 years has increased strongly, statistical concepts for descriptive modelling are still largely prevalent over mechanistic concepts for explanatory and predictive applications. Yet, considering the increasing importance of disturbances for forest dynamics and ecosystem stewardship under anthropogenic climate change, the latter concepts are crucial tool for understanding and coping with change in forest ecosystems. Current challenges for disturbance modelling in forest ecosystems are thus (i) to overcome remaining limits in process understanding, (ii) to further a mechanistic foundation in disturbance modelling, (iii) to integrate multiple disturbance processes in dynamic ecosystem models for decision support in forest management, and (iv) to bring together scaling capabilities across several levels of organization with a representation of system complexity that captures the emergent behaviour of disturbance regimes.

Caplat and Anand (2009) Effects of disturbance frequency, species traits and resprouting on directional succession in an individual-based model of forest dynamics. Journal of Ecology

by Paul Caplat

Jenkins, DG. 2011. Ranked species occupancy curves reveal common patterns among diverse metacommunities. Global Ecology & Biogeography 20:486-497.

by Dave Jenkins

Modelling Mediterranean landscape succession-disturbance dynamics: A landscape fire-succession model

by James Millington

Millington, J.D.A., Wainwright, J., Perry, G.L.W., Romero-Calcerrada, R. and Malamud, B.D. (2009) Environmental Modelling and Software 24 1196-1208

We present a spatially explicit Landscape Fire-Succession Model (LFSM) developed to represent Mediterranean Basin... more We present a spatially explicit Landscape Fire-Succession Model (LFSM) developed to represent Mediterranean Basin landscapes and capable of integrating modules and functions that explicitly represent human activity. Plant-functional types are used to represent spatial and temporal competition for resources (water and light) in a rule-based modelling framework. Vegetation dynamics are represented using a rule-based community-level modelling approach that considers multiple succession pathways and vegetation climax states. Wildfire behaviour is represented using a cellular-automata model of fire spread that accounts for land-cover flammability, slope, wind and vegetation moisture. Results show that wildfire spread parameters have the greatest influence on two aspects of the model: land-cover change and the wildfire regime. This sensitivity highlights the importance of accurately parameterising this type of grid-based model for representing landscape-level processes. We use a pattern-oriented modelling approach in conjunction with wildfire power-law frequency-area scaling exponent β to calibrate the model. Parameters describing the role of soil moisture on vegetation dynamics are also found to significantly influence land-cover change. Recent improvements in understanding the role of soil moisture and wildfire fuel loads at the landscape-level will drive advances in Mediterranean LFSMs.

Patterns of praying mantid population density following cyclone disturbance in far north Queensland, Australia

by James O'Hanlon

A sensitive slope: estimating landscape patterns of forest resilience in a changing climate

by Eric Pedersen

Anthropogenic disturbance and edge effects on anuran ensembles inhabiting Cloud Forest fragments in Colombia.

by Nicolas Urbina-Cardona

Effects of clam harvesting on sexual reproduction of the seagrass Zostera noltii

by Ana Alexandre

Marine Ecology Progress Series 298: 115-122

The sexual reproduction of Zostera noltii in Ria Formosa lagoon (southern Portugal) was assessed by quantifying the... more The sexual reproduction of Zostera noltii in Ria Formosa lagoon (southern Portugal) was assessed by quantifying the variation in both flowering effort and evolution of maturation stages during the fertile season. The effects of clam harvesting on the sexual reproduction of Z. noltii were investigated using both descriptive and experimental approaches. Meadows disturbed by clam harvest were compared with undisturbed meadows in two sectors of the lagoon. In both sectors, disturbed meadows showed significantly lower vegetative shoot density and significantly higher reproductive effort. The reproductive effort in the western disturbed meadows was two-fold higher than in undisturbed meadows, whereas in eastern disturbed meadows it was four-fold higher. In disturbed meadows, early maturation stages were found until the end of the flowering season and higher seed production was observed. Both the negative effect of clam harvesting on Z. noltii density and the positive effect on its reproductive effort were confirmed by manipulative field experiments. Plots that were experimentally harvested during the fertile season showed significantly lower vegetative shoot density and higher reproductive effort than unharvested plots. Results suggest that Z. noltii responds to clam harvest disturbance by both increasing its reproductive effort and extending its fertile season.

Three centuries of fire in montane pine‐oak stands on a temperate forest landscape

by Serena Aldrich

The role of disturbance in the co‐existence of the evergreen Quercus ilex and the deciduous Quercus cerrioides

by Consuelo Bonfil

A Creative Perspective of Environmental Impacts by Native Amazonian Human Populations.

by Stanford & Eglee Zent

1998 Interciencia. 23(4):232-240

Canopy openings in a primary neotropical lowland forest.

by Buck (Robert L., Jr.) Sanford