Presentation on theme: "Modeling the distribution of Pinus strobus L. at the beginning of the 19 th century in central Quebec (Canada) using presettlement land survey records."— Presentation transcript:
Modeling the distribution of Pinus strobus L. at the beginning of the 19 th century in central Quebec (Canada) using presettlement land survey records Eduard Mauri Ortuno 1, Frédérik Doyon 2, Alison Munson 1 1 Centre d’étude de la forêt, Faculté de foresterie, géographie et géomatique, Université Laval 2 Université du Québec en Outaouais, Institut québécois d’aménagement de la forêt feuillue Introduction Eastern white pine (WP) is one of the most valuable conifers in eastern North America and part of our ecological heritage. In the province of Quebec, according to historical records, by 1900 the most accessible mature specimens had been selectively logged, particularly along the St. Lawrence River and its major tributa- ries, leaving relic populations that are poorly representative of its presettlement distribution 1, 2, 4, 5, 8. For example, in the study area, mature WP prevalence decrea- sed from 28 % in the 19 th century (land survey observations) to a current 14 %, while conserving a high site fidelity 6. In La Mauricie national park (province of Quebec), WP volume passed from 12.5 % in the 19 th century to a current 0.5 % 7, 10. Because WP presettlement abundance is unknown and its present distribution has been largely reduced, we aim to develop a tool to guide its ecological restoration. Results WP 19 = f (env) Drainage was correlated with soil deposits, and slope did not add any extra information. Methods 19 th century WP (WP 19 ) WP presence/absence is obtained from 13 land survey logbooks dating from 1795 to 1895. 2614 observation points were extracted. References (1) Bouchard, P. 1999. Étude sur l'importance relative du pin blanc à l'intérieur des forêts naturelles du parc national de La Mauricie. Del Degan, Massé et Associés inc., Québec, QC. (2) Brisson, J., and Bouchard, A. 2003. In the past two centuries, human activities have caused major changes in the tree species composition of Acknowledgments Discussion The model WP 19 = f (env) is similar to known WP autoecology. Its weak prediction is due to the high frequency of glacial deposits (66 % of survey points), which are not statistically significant to predict WP 19 presence/absence. Because glaciolacustrine and marine deposits (well drained and coarse textured) are situated near the Saint Lawrence Lowlands where settlement started, WP would have already been harvested there before land surveys were carried out. A more accurate model is WP 19 = f (traces 20 ), but it has two main handicaps: no possible remote sensing for traces 20, stump decomposition will erase this past evidence. Using abundance of WP 19 and traces 20, instead of pre- sence/absence did not improve the models’ prediction. The frequency of each cover association with WP 19 can be used to guide a more comprehensive restoration. In the region, major users would be: Projet Triade: forest ecosystem management, La Mauricie national park: WP restoration program. Models presented here can be extended to the entire ecological region but not to the Saint Lawrence valley, due to major differences in topography and soil deposits. However, similar studies could be carried out. Objective and hypothesis 1.Understand the presettlement distribution of WP in the central Mauricie region (province of Quebec), by relating past WP presence, as described by primeval land survey records, to environmental variables and current traces. 2.Create a tool to guide the ecological restoration of WP, and its forests types, for the central Mauricie region. The hypotheses are: Eastern white pine (Pinus strobus L.) The species is a long-lasting pioneer favoured by surface fires, which burn the organic horizon and expose the mineral soil needed for seed germination. Because of its sensitivity to light competition at a young age, it is usually relegated to well-drained, coarse-textured sites 11, where the cover takes more time to close. Eastern white pine is present through all successional stages, among conifers as well as shade tolerant and intolerant hardwoods, but it rarely forms pure stands 12. Which environmental conditions did WP occupy in presettlement forests? WP 19 = f (env) Are current WP traces reliable to describe past WP distribution? WP 19 = f (traces 20 ) Which species accompanied WP in presettlement conditions? Associations WP 19 = f (env) Study area It is limited by the intersection of the Mauricie region (province of Quebec) and the Acer saccharum-Betula alleghaniensis bioclimatic domain (about 7,000 km 2 ), part of the Great Lakes-St. Lawrence forest. Landscape is mainly covered by glacial and fluvio-glacial deposits, with a relief composed of hills and high-hills, with moderate and steep slopes. Climate is continental subpolar, subhumid, with an average temperature of 3°C, 900 to 1,400 mm rainfall, and 160 to 180 growing season days 9. Current WP traces (traces 20 ) Obtained from 421 randomly chosen land survey points: 222 with WP 19 199 without WP 19 The plot radius of 20 m was established as the depth the surveyor could distinguish the vegetation. Traces 20 were the abundance of: WP stumps Mature WP WP saplings WP seedlings Environmental conditions (env) Obtained from photo interpretation or digital elevation model. envtypecat. Soil deposit Nominal6 DrainageOrdinal7 SlopeCont.- AspectNominal4 Slope position Nominal3 WP 19 = f (traces 20 ) Associations with WP 19 The order of abundance of each taxon was transformed to frequency using the broken stick model 3. Retaining taxa present in more than 1% of observation points, a hierarchical cluster analysis was performed on the 737 points containing WP 19 to create six cover associations. Associations WP 19 = f (env) The multinomial logistic regression was not significant, nor univariate regression with only one environmental predictor at a time. WP ecological restoration tool Probabilities from the model WP 19 = f (env) are calculated for a 19 x 19 m cell grid, covering the study area where environmental predictors are available. There are 72 possible environmental combina- tions. Of these combinations, 60, covering 99.4 % of the study area, are taken into account by the model. 49 % of this area, according to the 0.28 threshold, has a higher chance of WP 19 presence than absence. Probability of WP 19 presence ranges from 0.08 to 0.50. envWP 19 prevalence estimates Deposit Outwash-Alluvion45 %0.86 ** Thin glacial-Rocky36 %0.37 ** Glaciolacustrine-Marine12 %-1.00 ** Glacial26 %Not sig. Ice-marginal27 %Not sig. Organic20 %Not sig. Aspect S-SW-W34 %0.19 ** NE-E-SE24 %-0.25 ** NW-N27 %Not sig. Flat28 %Not sig. Slope position Top-High slope35 %0.29 ** Mid-Bottom slope27 %Not sig. Valley-Flat23 %-0.22 ** Overall28 % GeoreferenciationDB compilation GIS spatial DB Nagelkerke R 2 = 0.05Threshold = 0.28 Predicted noyesTotal Observed no10588191877 yes304433737 total136212522614 Sensitivity59 % overall correct57 % Specificity56 % traces 20 estimates Stumps1.26 ** Seedlings1.59 ** Saplings1.47 ** Mature WPNot sig. WP 19 = f(env) WP 19 = f(traces 20 ) Associations WP 19 = f(env) Stumps, seedlings and saplings are positively related to WP 19 presence. Steven Katovich, USDA Forest Service Old white pine stump Management history 1830 – 1850: beginning of WP selective cuts 1850 – 1890: WP is still the most exploited species 1890: mature WP depletion 2, 3, 5. 20 km southern Quebec, Canada. Ecoscience 10(2): 236-246. (3) Frontier, S. 1976. Decrease of eigenvalues in princiapal component analysis - comparison with broken stick model. Journal of Experimental Marine Biology and Ecology 25(1): 67-75. (4) Gélinas, C. 1984. L'exploitation et la conservation forestière au parc national de La Mauricie 1830-1940 : dossier documentaire. Parcs Canada, Québec, QC. (5) Lafleur, N. 1970. La drave en Mauricie, des origines à nos jours : histoire et traditions. 1 st ed. Éditions du Bien public, Trois-Rivières, QC. (6) Mauri Ortuno, E., Doyon, F., and Munson, A. 2008. Poster: Modélisation de la distribution du pin blanc au début du 19 e siècle dans la Moyenne-Mauricie. Colloque Triade. Shawinigan, QC, september 25-26, 2008. (7) Pelletier, H. 1998. Plan de conservation des écosystèmes terrestres, parc national de La Mauricie. Service de la conservation des ressources naturelles, Parcs Canada, Québec, QC. (8) Quenneville, R., and Thériault, R. 2001. La restauration des écosystèmes de pin blanc (Pinus strobus) - Un enjeu majeur pour le parc national de La Mauricie. Le Naturaliste canadien 125(2): 39-42. (9) Robitaille, A., and Saucier, J.-P. 1998. Paysages régionaux du Québec méridional. 1 st ed. Les Publications du Québec, Sainte-Foy, QC. (10) Service de conservation des ressources naturelles. 1998. Cadre la restauration écologique du pin blanc au parc national de la Mauricie. Parcs Canada, Québec, QC. (11) Vlasiu, P.D., Nolet, P., and Doyon, F. 2001. Le pin blanc - Revue de littérature. Institut québécois d’aménagement de la forêt feuillue, QC. (12) Wendel, G.W., and Smith, H.C. 1990. Eastern White Pine. In Conifers. Edited by R. M. Burns, and B. H. Honkala. United States Department of Agriculture, Forest Service, Washington, DC. Nagelkerke R 2 = 0.24Threshold = 0.53 Predicted noyesTotal Observed no15049199 yes75147222 total225196421 Sensitivity66 % overall correct71 % Specificity75 % study area survey point with WP 19 survey point without WP 19 Stepwise logistic regression This represents a state where WP was still within natural ranges.