Contrasting current and potential productivity and the influence of fire and species composition in the boreal forest: a case study in eastern Canada

2015 ◽  
Vol 45 (5) ◽  
pp. 541-552 ◽  
Author(s):  
Rija Rapanoela ◽  
Frédéric Raulier ◽  
Sylvie Gauthier ◽  
Hakim Ouzennou ◽  
Jean-Pierre Saucier ◽  
...  

The capacity of a forest stand to produce timber is related to the interactions that exist between its regeneration capacity, physical site characteristics (climate, surficial deposit, drainage), and disturbances. Minimally, to be sustainably managed, a forest needs to be sufficiently productive and able to regenerate after a disturbance so that its productive capacity is maintained or enhanced. To this effect, we evaluated timber productivity over a large area (175 000 km2) covering the latitudinal extent of closed-canopy black spruce (Picea mariana (Mill.) B.S.P) forest. Site index and relative density index were used to identify stands that cannot reach a minimum volume of trees of minimum size over one rotation. A nonparametric method was used to estimate their values for all stands within the study area. This imputation used either physical site attributes alone to assess potential productivity independent of stand history or physical and vegetation site attributes to assess current productivity. The proportion of productive stands was then estimated at the scale of landscapes ranging from 39 to 2491 km2. Physical site factors alone explain 84% of the variability in the percentage of potentially productive stands (78% for currently productive stands); their combination resulted in an abrupt transition in productivity over the study area. However, burn rate alone also explains 63% of variation in the proportion of currently productive stands and 41% of the relative difference between percentages of potentially or currently productive stands. These results have implications for strategic forest management planning at land classification stage, as timber production area is assumed to remain stable through time, whereas it is apparently related to the disturbance rate.

2020 ◽  
Vol 66 (3) ◽  
pp. 275-283 ◽  
Author(s):  
Halli Hemingway ◽  
Mark Kimsey

Abstract Accurate measures of forest site productivity are essential for forest-management planning. The most common measure of site productivity is breast height–age site index (BHASI)—the expected height at a reference age. Error from including early growth in productivity estimates and limited applicability of any one BHASI model warrant development of alternative methods. Exploring alternatives may only be necessary if regional BHASI models are not accurately predicting growth rates. We compared modeled height growth rates for Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca) to felled-tree measurements to evaluate relative performance of a regional BHASI model. An orthogonal sampling design ensured samples were collected across a range of site factors known to influence Douglas-fir growth rates. Growth rates for each 10 m section were calculated and compared to BHASI modeled growth rates. The regional BHASI model underpredicted growth rates from breast height to 30 m. Observed growth rates from 10 to 30 m accounted for the majority of underprediction relative to BHASI modeled growth rates. An alternative multipoint method of defining site productivity is described. More research comparing BHASI and alternative methods is needed, given the growth rate error associated with one-point site productivity assessment.


2006 ◽  
Vol 36 (3) ◽  
pp. 519-528 ◽  
Author(s):  
Robert F Powers

The capacity of a forest site to capture carbon and convert it into biomass defines fundamental site productivity. In the United States, the National Forest Management Act (NFMA) of 1976 mandates that this capacity must be protected on federally managed lands. Responding to NFMA, the USDA Forest Service began a soil-based monitoring program for its managed forests. Lacking an extensive research base, soil-based standards were predicated largely on professional judgment. To provide a stronger foundation, a national program of Long-Term Soil Productivity (LTSP) research was established. The LTSP program addresses both short- and long-term consequences of site and soil disturbance on fundamental forest productivity. Research centers on two key properties affecting a site's long-term productive capacity, site organic matter and soil porosity, each of which is readily influenced by management. A coordinated research network of more than 100 field installations in the United States and Canada is examining how pulse changes in these properties affect soil processes supporting vegetative growth and potential productivity. Results from installations with ≥5 years of response were presented on the 10th anniversary of LTSP, and the latest findings are assembled here. This paper describes the evolution of the study and the characteristics of the oldest field installations.


2011 ◽  
Vol 28 (3) ◽  
pp. 146-151 ◽  
Author(s):  
Alain Paquette ◽  
Jean-Pierre Girard ◽  
Denis Walsh

Abstract Although studies in the past have reported that the deeper planting of conifers has no effect on seedling performance, most planting guidelines in use today still recommend that seedlings be planted to the rootcollar. Past studies were mostly observational, used bareroot seedlings, and often reported early results from just one or two depths of planting treatments. Most of the results available regarding planting depth for boreal species are anecdotal, although they are planted by the hundreds of millions every year. The present study reports no short-term (1 year) or long-term (15 to 19 years) negative effect of planting depth on the survival and height and diameter growth of black spruce, white spruce, and jack pine seedlings over three large, replicated experiments in the boreal forest of eastern and northern Quebec (eastern Canada). Four different depth treatments were compared, from manual planting at the rootcollar to the deepest mechanical planting treatment at 10 cm or more, making this the largest, longest-lasting study of its kind. Although, as expected, important differences in growth were present between species, all three commonly planted conifers reacted similarly to the planting depth treatments (no effect). This result can in part be attributed to an almost perfect control of frost heaving in the deepest two treatments. Planting depth effects were assessed using analysis of variance, multiple Tukey honestly significant difference, and uncorrected pairwise one-tailed t-tests to increase the probability of detecting a negative effect. Absolute differences and effect sizes (generally small and often positive with greater depths) were also analyzed.


2019 ◽  
Vol 11 (19) ◽  
pp. 2227 ◽  
Author(s):  
Amine Merzouki ◽  
Heather McNairn ◽  
Jarrett Powers ◽  
Matthew Friesen

Soil moisture is a factor for risk analysis in the agricultural sector, yet access to temporally and spatially detailed data is challenging for much of the world’s agricultural extend. Significant effort has been focused on developing methodologies to estimate soil moisture from microwave satellite sensors. Canada’s RADARSAT Constellation Mission (RCM) is capable of acquiring imagery in a number of modes with a Compact Polarimetry (CP) configuration at different spatial resolutions (1 to 100 m). RCM offers greater polarization diversity, wide swaths and improved temporal frequency (4-day exact revisit time); all important considerations for large area monitoring of agricultural resources. The major goal of this study was to examine whether CP could accurately estimate surface soil moisture over bare fields. A methodology was developed using the calibrated Integral Equation Model (IEM) multi-polarization inversion approach. RADARSAT-2 data was acquired between 2012 and 2017 over a test site in eastern Canada. CP backscatter for two RCM modes (medium resolution 30 m and 50 m (MR30 and MR50)) was simulated using 63 RADARSAT-2 fully polarimetric images. A simple transfer function was developed between RH (right circular-horizontal) and HH (horizontal-horizontal) intensity, as well as RV (right circular-vertical) and VV (vertical-vertical). These HH- and VV-like intensities were then used in the multi-polarization inversion scheme to retrieve soil moisture. CP soil moisture retrievals were validated against soil moisture measurements from a long term in-situ network instrumented with five soil moisture stations. Retrieved and measured soil moisture were well correlated (R > 0.70) with an unbiased root mean square error (ubRMSE) less than 0.06 m3/m3. Overall, the developed method clearly captured the dry down and wetting trends observed through the five years study period. However, results demonstrated that the inversion method introduced a consistent bias (~0.10 m3/m3). Comparison of CP soil moisture estimates to those from the Soil Moisture Active Passive (SMAP) passive microwave satellite confirmed this bias. This study demonstrates the potential of C-band CP data to deliver accurate soil moisture products over wide swaths for regional and national soil moisture monitoring.


Ecoscience ◽  
2011 ◽  
Vol 18 (3) ◽  
pp. 279-294 ◽  
Author(s):  
François Girard ◽  
Serge Payette ◽  
Réjean Gagnon

1967 ◽  
Vol 45 (9) ◽  
pp. 1703-1714 ◽  
Author(s):  
E. Von Rudloff

The leaf oils from white and black spruce obtained from different locations in Western and Eastern Canada, Michigan, and Minnesota, have been analyzed by gas liquid chromatography. Both species were found to have a remarkably consistent and distinctive distribution pattern of the leaf oil terpenes. The quantitative variations encountered in samples of the same species from different populations are relatively small and ecological differences are not found to affect the leaf oil composition. Hence, analysis of spruce leaf oils appears to be highly suitable for a study of introgression and hybridization.


2007 ◽  
Vol 37 (1) ◽  
pp. 62-73 ◽  
Author(s):  
Martin Lavoie ◽  
David Paré ◽  
Yves Bergeron

The surface of the soil in recently harvested or burned lowland black spruce (Picea mariana (Mill.) BSP) sites is composed of a fine mosaic of different bryophytes (mostly Sphagnum spp. and feathermosses), disturbed organic material originating mostly from mosses at different stages of decay, and exposed mineral soil. Growth substrates were compared in lowland black spruce stands regenerating after either careful logging or wildfire. The 3-year annual increment for black spruce seedlings was greatest with substrates of feathermosses, mainly Pleurozium schreberi (Brid.) Mitt., fibric material of P. schreberi origin, and a mixture of fibric P. schreberi and humic materials; it was least with fibric Sphagnum spp., mineral soil, and decaying wood substrates. The most favourable substrates for growth were characterized by better black spruce N and P foliar status. Our results also suggest that categories of growth substrates in the rooting zone reflect nutritional quality better than categories of growth substrates on the soil surface. To maintain or increase black spruce growth following careful logging of sites prone to paludification, we recommend fill-planting of seedlings in substrates originating from P. schreberi; management techniques that favour P. schreberi over Sphagnum mosses should also be developed.


2020 ◽  
Vol 12 (12) ◽  
pp. 2056 ◽  
Author(s):  
Parinaz Rahimzadeh-Bajgiran ◽  
Chris Hennigar ◽  
Aaron Weiskittel ◽  
Sean Lamb

A fine-resolution region-wide map of forest site productivity is an essential need for effective large-scale forestry planning and management. In this study, we incorporated Sentinel-2 satellite data into an increment-based measure of forest productivity (biomass growth index (BGI)) derived from climate, lithology, soils, and topographic metrics to map improved BGI (iBGI) in parts of North American Acadian regions. Initially, several Sentinel-2 variables including nine single spectral bands and 12 spectral vegetation indices (SVIs) were used in combination with forest management variables to predict tree volume/ha and height using Random Forest. The results showed a 10–12 % increase in out of bag (OOB) r2 when Sentinel-2 variables were included in the prediction of both volume and height together with BGI. Later, selected Sentinel-2 variables were used for biomass growth prediction in Maine, USA and New Brunswick, Canada using data from 7738 provincial permanent sample plots. The Sentinel-2 red-edge position (S2REP) index was identified as the most important variable over others to have known influence on site productivity. While a slight improvement in the iBGI accuracy occurred compared to the base BGI model (~2%), substantial changes to coefficients of other variables were evident and some site variables became less important when S2REP was included.


Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 234 ◽  
Author(s):  
Ranjith Gopalakrishnan ◽  
Jobriath Kauffman ◽  
Matthew Fagan ◽  
John Coulston ◽  
Valerie Thomas ◽  
...  

Sustainable forest management is hugely dependent on high-quality estimates of forest site productivity, but it is challenging to generate productivity maps over large areas. We present a method for generating site index (a measure of such forest productivity) maps for plantation loblolly pine (Pinus taeda L.) forests over large areas in the southeastern United States by combining airborne laser scanning (ALS) data from disparate acquisitions and Landsat-based estimates of forest age. For predicting canopy heights, a linear regression model was developed using ALS data and field measurements from the Forest Inventory and Analysis (FIA) program of the US Forest Service (n = 211 plots). The model was strong (R2 = 0.84, RMSE = 1.85 m), and applicable over a large area (~208,000 sq. km). To estimate the site index, we combined the ALS estimated heights with Landsat-derived maps of stand age and planted pine area. The estimated bias was low (−0.28 m) and the RMSE (3.8 m, relative RMSE: 19.7%, base age 25 years) was consistent with other similar approaches. Due to Landsat-related constraints, our methodology is valid only for relatively young pine plantations established after 1984. We generated 30 m resolution site index maps over a large area (~832 sq. km). The site index distribution had a median value of 19.4 m, the 5th percentile value of 13.0 m and the 95th percentile value of 23.3 m. Further, using a watershed level analysis, we ranked these regions by their estimated productivity. These results demonstrate the potential and value of remote sensing based large-area site index maps.


2001 ◽  
Vol 31 (12) ◽  
pp. 2160-2172 ◽  
Author(s):  
Martin Simard ◽  
Serge Payette

Black spruce (Picea mariana (Mill.) BSP) is the dominant tree species of the southernmost (48°N) lichen woodlands in eastern Canada. Most spruce trees in mature lichen woodlands appear to be declining, as shown by the massive invasion of the epiphytic lichen Bryoria on dead branches of dying trees. A dendroecological study was undertaken to identify the main causal factors of the decline. A decline index based on the abundance of Bryoria on spruce trees was used to distinguish healthy from damaged lichen–spruce woodlands and to select sampling sites for tree-ring measurements. Three conifer species (black spruce, balsam fir (Abies balsamea (L.) Mill.), and jack pine (Pinus banksiana Lamb.)) were sampled to compare their growth patterns in time and space. In the late 1970s and mid-1980s, black spruce and balsam fir experienced sharp and synchronous radial-growth reductions, a high frequency of incomplete and missing rings, and mass mortality likely caused by spruce budworm (Choristoneura fumiferana (Clem.)) defoliation. Jack pine, a non-host species, showed no such trend. Because black spruce layers were spared, lichen woodlands will eventually regenerate unless fire occurs in the following years. Black spruce decline can thus be considered as a normal stage in the natural dynamics of the southern lichen woodlands.


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