Characterizations of boreal anthropogenic disturbance regimes from multi-scalar Earth observations by Paul Drew Pickell B.A.S. The Evergreen State College, 2011 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in The Faculty of Graduate and Postdoctoral Studies (Forestry) The University of British Columbia (Vancouver) December 2015 © Paul Drew Pickell, 2015 Abstract Anthropogenic disturbance regimes are anticipated to overwhelm Earth’s ecosystems during the Anthropocene. Boreal forests are particularly at risk of significant transition due to human appropriation of renewable and non-renewable resources. Forestry and energy development in the boreal forest have three primary ecological consequences: suppression of historical disturbance regimes such as fire; emergence of novel ecosystems; and the eradication of ecological memory, which maintains ecological integrity. The objective of this dissertation is to improve our understanding of the pattern characteristics of anthropogenic disturbance regimes in order to mitigate the negative, unintended outcomes of managed boreal forests. Anthropogenic disturbance from forest harvesting and energy development was mapped for industrialized landscapes of Alberta, Canada between 1949 and 2012. A comparative analysis using spatial models of unsuppressed fires sampled across Alberta and Saskatchewan and aerially-interpreted forest inventory data revealed that the anthropogenic disturbance patterns were beyond the historical range-of-variability in terms of disturbed area, largest patch size, and undisturbed forest remnants. When the spatial data were segmented based on a recent period of intensive energy development, it was determined that energy development in Alberta was a major driver of cumulative anthropogenic disturbance patterns. Levels of undisturbed forest remnants within anthropogenic disturbances declined between 18-34% and edge density increased between 15-175% following energy development. Landscape-level patterns of forest cover changes were assessed using a time series of satellite imagery between 1985 and 2010. Forest disturbance was classified as resource extraction or fire in the Foothills of Alberta with 94% overall accuracy. The rate of resource extraction exceeded fire, accounting for 86% of annual forest disturbance, indicating that fire was suppressed in the landscape. A time series pattern analysis approach applied across Canada demonstrated that managed boreal forests were associated with rising edge density, declining core forest cover, and declining largest forest patch size. Boreal forests that had low disturbance rates were characterized by inherent forest cover pattern variation. ii This dissertation advanced new perspectives on conceptualizing, detecting, and characterizing patterns of anthropogenic disturbance regimes. Future work is identified primarily around the development and interpretation of landscape structure thresholds and transition indicators. iii Preface The research questions and objectives of this dissertation were originally conceived from discussions between me and my supervisory committee. Portions of this dissertation appear as co-authored publications in peer-reviewed journals. For these publications, I performed the primary research, data analysis and interpretation, and prepared the final manuscript: Chapter 2: Pickell, P.D., Gergel, S.E., Coops, N.C., and Andison, D.W. (2014). Monitoring forest change in landscapes under-going rapid energy development: Challenges and new perspectives. Land 3(3): 617-638. doi:10.3390/land3030617 Chapter 3: Pickell, P.D., Andison, D.W., and Coops, N.C. (2013). Characterizations of anthropogenic disturbance patterns in the mixedwood boreal forest of Alberta, Canada. Forest Ecology and Management 304: 243-253. doi:10.1016/j.foreco.2013.04.031 Chapter 4: Pickell, P.D., Andison, D.W., Coops, N.C., Gergel, S.E., and Marshall, P.L. (2015). The spatial patterns of anthropogenic disturbance in the western Canadian boreal forest following oil and gas development. Canadian Journal of Forest Research 45(6): 732-743. doi:10.1139/cjfr-2014-0546 Chapter 5: Pickell, P.D., Hermosilla, T., Coops, N.C., Masek, J.G., Franks, S., and Huang, C. (2014). Monitoring anthropogenic disturbance trends in an industrialized boreal forest with Landsat time series. Remote Sensing Letters 5(9): 783-792. doi:10.1080/2150704X.2014.967881 Chapter 6: Pickell, P.D., Hermosilla, T., Frazier, R., Coops, N.C., and Wulder, M.A. (2016). Forest recovery trends derived from Landsat time series for North American boreal forests. International Journal of Remote Sensing 37(1): 138-149. doi:10.1080/2150704X.2015.1126375 Chapter 6: Pickell, P.D., Coops, N.C., Gergel, S.E., Andison, D.W., and Marshall, P.L. Managed boreal forests drive rapidly changing landscape patterns over the last three decades in Canada. (in review) P. D. P. Faculty of Forestry The University of British Columbia iv Table of Contents Abstract....................................................................................................................................... ii Preface ...................................................................................................................................... iv Table of Contents ........................................................................................................................ v List of Tables ............................................................................................................................. ix List of Figures ............................................................................................................................. x List of Abbreviations ................................................................................................................. xiii Acknowledgements ................................................................................................................... xv Dedication ................................................................................................................................ xvi 1. Introduction ............................................................................................................................ 1 1.1 Boreal forests as a case study during the Anthropocene ............................................. 1 1.2 Critical research needs during the Anthropocene ......................................................... 6 1.3 Research questions ..................................................................................................... 6 1.4 Dissertation overview ................................................................................................... 7 2. Overview of anthropogenic disturbance regimes .................................................................... 9 2.1 Human transformation of forests during the Anthropocene .......................................... 9 2.2 Conceptualizing forest land use as a disturbance regime............................................10 2.2.1 Defining anthropogenic disturbance .....................................................................10 2.2.2 Challenges for characterizing anthropogenic disturbance regimes .......................11 2.3 Ecological impacts of energy development .................................................................14 2.3.1 Clearing of forest for non-renewable resources ....................................................16 2.3.2 Persistent linear corridors ....................................................................................18 2.3.3 Suppression of historical disturbance regimes .....................................................21 2.3.4 Introduction of novel ecosystems .........................................................................22 2.3.5 Eradication of ecological memory ........................................................................24 2.4 Detecting anthropogenic disturbance regimes ............................................................26 3. Characterizations of anthropogenic disturbance patterns in the mixedwood boreal forest of Alberta, Canada ........................................................................................................................30 3.1 Introduction .................................................................................................................30 3.2 Materials and methods ................................................................................................32 3.2.1 Study area ...........................................................................................................32 3.2.2 Historical fire data ................................................................................................35 v 3.2.3 Anthropogenic disturbance data ..........................................................................35 3.2.4 Disturbance pattern language ..............................................................................38 3.2.5 NEPTUNE decision-support tool ..........................................................................40 3.2.6 Disturbance event pattern indices ........................................................................40 3.2.7 Data pre-processing .............................................................................................41 3.2.8 Statistical analysis ...............................................................................................41 3.3 Results ........................................................................................................................42
Details
-
File Typepdf
-
Upload Time-
-
Content LanguagesEnglish
-
Upload UserAnonymous/Not logged-in
-
File Pages166 Page
-
File Size-