scholarly journals Québec forest ecological classification program

1992 ◽  
Vol 68 (1) ◽  
pp. 53-63 ◽  
Author(s):  
Jean-François Bergeron ◽  
Jean-Pierre Saucier ◽  
Denis Robert ◽  
André Robitaille

In 1986, the ministère des Forêts du Québec instituted a provincial program to study forest ecosystems entitled the "Forest Ecological Classification (FEC) Program." Under this program, a multidisciplinary team was charged with conducting ecological surveys, analyzing and characterizing the variables of the physical environment, classifying vegetation and preparing integrated forest inventory maps. Their goal is to complete the ecological classification of the forests in all territories south of the 52nd parallel. To undertake such a vast project, it was necessary to prepare detailed methodological guides for data collection, data analysis and mapping. The following products are now available for many different ecological regions: classifications of forest types, toposequences, physiographic and surface deposit maps and integrated forest inventory maps. Multivariate analysis methods are used in analyzing ecological data; in this way, hierarchical classifications and ordinations can be used as the basis for identifying and describing forest types, vegetation-physical environment relationships and successional patterns. Such ecological classification products are an indispensable tool for forest managers and users. Key words: ecological classification, forest ecology, forest management, forest site classification, multivariate analysis, physical environment, Québec.

1992 ◽  
Vol 68 (1) ◽  
pp. 25-33 ◽  
Author(s):  
W. J. Meades ◽  
B. A. Roberts

This paper provides a review of past and present forest site classification activities in Newfoundland and Labrador over the last thirty years. Initially, research concentrated on the development of a classification system using floristic and edaphic criteria to define forest types. This was followed by a period in which the relationships between forest types and stand productivity were assessed. Subsequently, pilot projects were undertaken in which the forest site classification was incorporated into the biophysical land classification approach and applied to forest capability mapping. In recent years the trend towards more intensive forest management has rekindled interest in forest site classification: emphasis is being placed on technology transfer of site classification to operational foresters in industry and government. Key words: Forest classification, site classification, soils, vegetation, Newfoundland, Labrador, forest ecology


1992 ◽  
Vol 68 (1) ◽  
pp. 42-52 ◽  
Author(s):  
L. Bélanger ◽  
C. Camiré ◽  
Y. Bergeron

After a brief review of floristic classifications, ecological survey, as carried out in Quebec, is described. Three stages of development of ecological survey over the past twenty-five years are identified: (1) the pioneer work of Jurdant; (2) major ecological surveys from the late 1960s to the late 1970s; and (3) the diversification of the groups involved in ecological land surveys beginning in the 1980s, including universities, the Quebec Environment Department (MENVIQ) and the Quebec Department of Energy and Resources (MER). Intended for use in integrated land management, ecological survey must be an effective integrator of the various ecological evaluations; the information must be easily communicable and the methodology must be flexible. Ecological land classification has two dimensions: (1) taxonomic; and (2) cartographic. In the taxonomic units, the ecological region, the ecological type and the ecological phase are identified. In cartographic terms, local (ecological phase and type), regional (ecological system and subsystem) and national (ecological district and region) resolution is identified.Quebec universities, MER and MENVIQ are presently involved in ecological land surveys. The new Forest Act, which was enacted in 1986 and which provides for sustainable yield and more intensive forest management, is a major force behind the promotion of the use of ecological inventories as the basis for management activities. Mapping of the ecological regions (1:1,250,000) has almost been completed in Quebec. Total coverage of the commercial forest as a function of ecological districts (1:250,000) could be completed within five years, and the mapping of ecological types (1:20,000) could be completed in 20 years at a rate of 10,000 km2 a year. Although in the past ecological land surveys have been used primarily for environmental impact analyses (for instance, the installation of hydroelectric equipment and transportation corridors), the ecological framework is presently being used to prepare development plans for a number of regional county municipalities (RCMs). Pilot projects are under way to assess the potential applications of the ecological framework to forestry as part of intensive management efforts. Improvements are needed in both the accessibility of the information provided by the ecological framework (maps, site guides) and the development of interpretative tools for silvicultural measures. Key words: ecological survey, ecosystem mapping, ecological land classification, forest ecology, forest site classification, Quebec.


Nativa ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 54-61
Author(s):  
Pábulo Diogo de Souza ◽  
Carlos Alberto Araújo Júnior ◽  
Christian Dias Cabacinha ◽  
Leandro Silva de Oliveira ◽  
Celso Dotta Lopes Junior ◽  
...  

As informações utilizadas para estimativa da capacidade produtiva de sítios florestais provêm de bases de dados de inventário florestal que podem conter observações discrepantes (outliers). Assim, torna-se necessário a análise de consistência para exclusão destes. Porém, os outliers podem representar determinado padrão de crescimento existente na floresta, logo a exclusão destes pode ser uma ação equivocada. Objetivou-se comparar a performance de diferentes técnicas de modelagem para classificação de sítios florestais, considerando uma base de dados com a presença de outliers. Utilizou-se pares de dados de idade e altura dominante (HD) de parcelas permanentes de Eucalyptus urophyla x Eucalyptus grandis localizadas no norte de Minas Gerais. Foi simulado um outlier de HD. A base de dados foi modelada, com e sem presença de outliers, por regressão linear (RL) e redes neurais artificiais Multilayer Perceptron (MLP) e Radial Basis Function (RBF). Os métodos foram analisados por meio dos critérios estatísticos de precisão: bias, raiz quadrada do erro médio, correlação de Pearson, erro médio percentual e gráfico de dispersão residual. A MLP foi superior para estimativa do índice de sítio. Portanto, a MLP é indicada para classificação de sítios florestais quando há presença de outliers na base de dados. Palavras-chave: índice de sítio; inventário florestal; dados discrepantes.   Performance of modeling for classification of forest sites in databases with outliers   ABSTRACT: The information used to estimate the productive capacity of forest sites comes from forest inventory databases that may contain discrepant observations (outliers). Thus, consistency analysis is required to exclude these. However, the outliers may represent a certain growth pattern existing in the forest, so their exclusion may be a mistaken action. The objective was to compare the performance of different modeling techniques for forest site classification, considering a database with the presence of outliers. We used pairs of data of age and dominant height (HD) of permanent parcels of Eucalyptus urophila x Eucalyptus grandis located in the north of Minas Gerais. A HD outlier was simulated. The database was modeled, with and without the presence of outliers, by linear regression (RL) and artificial neural networks Multilayer Perceptron (MLP) and Radial Basis Function (RBF). The methods were analyzed by means of precision statistical criteria: bias, square root of mean error, Pearson correlation, mean percentage error and residual scatter plot. The MLP was superior for site index estimation. Therefore, the MLP is indicated for forest site classification when there are outliers in the database. Keywords: site index; forest inventory; discrepant data.


2003 ◽  
Vol 154 (5) ◽  
pp. 149-160 ◽  
Author(s):  
François Ayer ◽  
Peter Lüscher ◽  
Simon Egli

17 forest sites in three Swiss cantons (Berne, Solothurn, Fribourg)were investigated mycologically during a four year period to find out to what extent higher fungi are bound to specific forest sites and whether they are suitable for characterizing forest types. The species lists reveal a species specific dependency on soil pH: 32% of the inventorized fungal species can be found in the whole pH range, 50% were found only in acid soils up to a pH of 5.75, and 18% in only neutral to alkaline soils. The species fructifying on slightly acid to neutral soils are considered to be possible indicator species for such environmental changes as acidification or eutrophisation. The present classification of higher fungi into pH-classes and forest types is a tentative one. The data set will be supplemented with further observations in order to attain a more definitive classification. These preliminary analyses, however, already reveal the suitability of higher fungi for characterizing and classifying forest types. The four-year investigation showed that pure coniferous forests are richer in macromycetes species than generally supposed and also that they harbour a higher percentage of mycorrhizal fungi than deciduous forests.


1990 ◽  
Vol 66 (2) ◽  
pp. 91-96 ◽  
Author(s):  
Dys Burger ◽  
Geoffrey Pierpoint

Classification trends during the past 60 years to serve different management needs are reviewed. These trends include the adaptation of European vegetation typology to Canadian conditions, the delineation of regions meaningful to forest management, the classification of forest ecosystems relevant to silviculture and of broader landscapes appropriate for integrated resource management and, finally, prime-site classification combining land features and technologic and socio-economic criteria to serve modern rationalization of management. Key words: Site classification, land classification, ecosystem classification, vegetation typology, ecological regions, forest ecology, land use planning, Canada.


2020 ◽  
Vol 13 (1) ◽  
pp. 77
Author(s):  
Tianyu Hu ◽  
Xiliang Sun ◽  
Yanjun Su ◽  
Hongcan Guan ◽  
Qianhui Sun ◽  
...  

Accurate and repeated forest inventory data are critical to understand forest ecosystem processes and manage forest resources. In recent years, unmanned aerial vehicle (UAV)-borne light detection and ranging (lidar) systems have demonstrated effectiveness at deriving forest inventory attributes. However, their high cost has largely prevented them from being used in large-scale forest applications. Here, we developed a very low-cost UAV lidar system that integrates a recently emerged DJI Livox MID40 laser scanner (~$600 USD) and evaluated its capability in estimating both individual tree-level (i.e., tree height) and plot-level forest inventory attributes (i.e., canopy cover, gap fraction, and leaf area index (LAI)). Moreover, a comprehensive comparison was conducted between the developed DJI Livox system and four other UAV lidar systems equipped with high-end laser scanners (i.e., RIEGL VUX-1 UAV, RIEGL miniVUX-1 UAV, HESAI Pandar40, and Velodyne Puck LITE). Using these instruments, we surveyed a coniferous forest site and a broadleaved forest site, with tree densities ranging from 500 trees/ha to 3000 trees/ha, with 52 UAV flights at different flying height and speed combinations. The developed DJI Livox MID40 system effectively captured the upper canopy structure and terrain surface information at both forest sites. The estimated individual tree height was highly correlated with field measurements (coniferous site: R2 = 0.96, root mean squared error/RMSE = 0.59 m; broadleaved site: R2 = 0.70, RMSE = 1.63 m). The plot-level estimates of canopy cover, gap fraction, and LAI corresponded well with those derived from the high-end RIEGL VUX-1 UAV system but tended to have systematic biases in areas with medium to high canopy densities. Overall, the DJI Livox MID40 system performed comparably to the RIEGL miniVUX-1 UAV, HESAI Pandar40, and Velodyne Puck LITE systems in the coniferous site and to the Velodyne Puck LITE system in the broadleaved forest. Despite its apparent weaknesses of limited sensitivity to low-intensity returns and narrow field of view, we believe that the very low-cost system developed by this study can largely broaden the potential use of UAV lidar in forest inventory applications. This study also provides guidance for the selection of the appropriate UAV lidar system and flight specifications for forest research and management.


1996 ◽  
Vol 26 (9) ◽  
pp. 1709-1713 ◽  
Author(s):  
Paul C. Van Deusen

Growth modeling of forests at the individual tree and stand levels is a highly refined procedure for many forest types. A method to incorporate predictions from such models into a forest inventory system is developed. Variance components from the actual measurements and from the predicted measurements are used to estimate the variance of the combined predicted value. The only assumption required to justify this method is that the model estimate has a bias that does not change from one time period to the next. The estimation procedure proposed here can also incorporate remotely sensed information via a regression estimator.


2005 ◽  
Vol 35 (10) ◽  
pp. 2382-2386 ◽  
Author(s):  
Paul C Van Deusen

Weighted estimation formulas are developed for producing stratified estimates of means and variances where data come from plots that can contain multiple forest conditions. Each plot is mapped to allow the analyst to focus on specific forest types or conditions. The weights required to accommodate mapped plots are somewhat more complicated than the weights for unmapped plots. In particular, these weights depend on the mapped condition of interest. The implication is that a single plot weight or expansion factor will not suffice for all analyses as it does for unmapped plots. The methods are demonstrated using USDA Forest Service inventory data.


Author(s):  
Jean Thioulouse ◽  
Stéphane Dray ◽  
Anne-Béatrice Dufour ◽  
Aurélie Siberchicot ◽  
Thibaut Jombart ◽  
...  

Author(s):  
V. P. Tkach ◽  
O. V. Kobets ◽  
M. G. Rumiantsev

The forest site capacity using was quantitatively assessed for the stands of the main forest-forming species of Ukraine, Scots pine and common oak, taking into account natural zones and forest types. The tables of productivity of modal and highly productive pine and oak stands have been developed. It has been found that the stands use an average of 50–75 % of the forest site capacity of lands. The average weighted value of the capacity used by pine forests was 68–76 % in the Polissya zone, 70–78 % and 68–73 % in the Right-bank and Left-bank Forest-Steppe zones respectively, and 54–78 % in the Steppe zone. For oak stands, the value was 71–75 % and 63–71 % for the Right-bank and Left-bank Forest-Steppe zones respectively and 65–75 % for the Steppe zone. The basis for increasing the productivity of forests was confirmed to be the differentiation of forest management systems and individual forestry activities on a zonal and typological basis.


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