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In this study, we conducted a controlled experiment to assess the growth and survival of balsam fir (Abies balsamea (L.) Mill.), red spruce (Picea rubens Sarg.), and red maple (Acer rubrum L.) seedlings in response to warming, drought, and elevated CO2, as projected under RCP 8.5 for North America’s Acadian Forest Region. In response to warming, only red spruce increased in height; however, this effect varied by CO2 and soil moisture treatments. Under the drought treatment, red spruce biomass was not affected, but mortality increased by 2%. With warming, increases in balsam fir height growth were only detected under certain soil moisture and CO2 conditions. Balsam fir biomass decreased by 24% under drought, while mortality increased by 5%. Warming did not improve red maple height growth, but it remained 7–50 times greater than that of the conifers and no mortality was observed. Overall, CO2 enrichment increased height growth of droughted seedlings relative to the ambient treatment, demonstrating an amelioration of the negative drought effect. Balsam fir was the least adapted to warming and drought, while red spruce displayed some positive responses. Although growth of red maple seedlings did not increase with warming, they exhibited greater absolute growth and survival, which suggests red maple may outperform both conifers under a warming climate.

Eruptive insect pests have significant impacts on the structure and function of forest ecosystems. Outbreaks of spruce budworm (Choristoneura fumiferana) (Clem.), for instance, occur approximately every 35–40 years, resulting in the loss of millions of hectares of spruce–fir forests in eastern North America. In addition to the density-dependent relationships that drive insect outbreaks, rising populations often coincide with drought events, which are expected to increase in both frequency and intensity in response to climate change. However, as populations approach the eruptive phase, consequences of intraspecific competition may outweigh the benefit of host water stress. The objective of our study was to quantify defoliation and insect performance responses to the interactive effects of drought and density of spruce budworm. To test for these interactions, we established a manipulative field experiment in a mature, balsam fir-dominated forest stand using a combination of single-tree rainout shelters and sleeve-caged insect larvae at four different densities: 0, 25, 50, or 100 individuals. Defoliation of 1-year old shoots, but not current-year shoots, significantly increased in response to higher insect densities. Density also had a significant, negative effect on budworm percent survival, although the total number of recovered adults remained highest in the high density treatment. Adult female body mass was significantly reduced in response to increased density, but only on droughted trees. Lastly, male wing length was significantly decreased in response to increased density. Overall, our results demonstrate that across a broad range of outbreak densities, rain exclusion had a minor impact. Accordingly, we anticipate that as insect pest populations approach epidemic levels, the influence of density on defoliation, insect survival, and body condition is likely to outweigh the impact of moderate drought stress.

Detection of spruce budworm (Choristoneura fumiferana Clem.) defoliation is critical for forest protection strategies aimed at minimizing losses in growth and mortality. However current aerial and ground survey methods of detecting defoliation are imprecise and subjective, limiting their usefulness. We evaluated the use of hemispherical crown canopy images to quantify annual spruce budworm defoliation, comparing images taken before and after defoliation in each of two years in 75 sample plots in Quebec, Canada. Gradient Boosting Machine analysis identified gap fraction change from May-October, gap fraction after defoliation, insecticide spraying, and % balsam fir (Abies balsamea (L.) Mill.) basal area as important explanatory variables of defoliation. Logistic Generalized Linear Model (GLM) and Random Forests (RF) models were trained on a random two-thirds of sample plots combining both years, and defoliation predictions were validated on the remaining one-third of plots. RF predictions consistently resulted in slightly higher correlations and lower root mean squared errors (RMSEs) than GLM predictions. Defoliation models including insecticide spraying, gap fraction change May-October, and % balsam fir basal area had RMSEs of 14–22%, whereas models excluding insecticide spraying had higher RMSEs of 18–24%. Model goodness-of-fit using two-sample Kolmogorov-Smirnov tests indicated that predicted and measured annual defoliation had similar distributions, with the exception of GLM and RF models excluding spray compared to ocular defoliation. Use of hemispherical images to quantify gap fraction change is a feasible, non-destructive, and objective method to assess canopy foliage changes caused by spruce budworm defoliation.

During spruce budworm (SBW; Choristoneura fumiferana (Clem.)) outbreaks, defoliation causes severe tree damage and mortality to spruce-balsam fir (Picea spp.-Abies balsamea (L.) Mill.) forests. Annual defoliation thematic maps provide vital information for forest protection planning against outbreaks, but such data are challenging to accurately collect over large areas during a short (2–3 week) period when damaged foliage peaks. Current operational methods for estimating annual defoliation are aerial surveys, through visual observations by professionals from small aircraft, defining broad defoliation classes which are subjective and spatially can be inaccurate. Remote sensing studies estimating annual defoliation are limited due to lack of ground verification data and difficulty of capturing spectral changes specific to the short detection period. Only one study has used satellite hyperspectral imagery to detect annual SBW defoliation, classifying just two classes of defoliation and using inaccurate aerial survey results for training and validation. In this paper, we introduce a new method to estimate annual SBW defoliation in three classes (light ≤ 30%, moderate 30–70%, and severe ≥ 70%), using change detection of vegetation indices (VIs) derived from satellite (EO-1 Hyperion) hyperspectral imagery acquired before and after annual defoliation. Random Forest and Support Vector Machine classifiers were used to classify defoliation, and intensive field measurements of branch-level defoliation per plot were used for accuracy assessment. Field plots, with spatially correlated defoliation within stands, were used to derive an additional 624 plots to obtain sufficient and independent datasets for training and validating the detection results. The top four VIs for detecting annual defoliation, based on Random Forest Total Variable Importance Score and Spearman's rank correlations, were Plant Senescence Reflectance Index, Normalized Difference Water Index, Moisture Stress Index, and Enhanced Vegetation Index. The spectral regions of VIs used to classify defoliation included visible, near-infrared, red-edge, and shortwave infrared. Accuracies of the light, moderate, and severe defoliation classes using our method ranged from 55–85%, 40–76%, and 40–80%, respectively, which were significantly higher than the 32% accuracy of aerial survey defoliation data for the plots.

En 2030, la depression occupera la premiere cause mondiale de morbidite selon l’Organisation mondiale de la sante. Le passage a l’acte suicidaire en est la complication la plus redoutee. Chez l’adolescent, une place croissante est accordee aux traitements non medicamenteux, et en particulier aux psychotherapies. Peu connue en France, malgre d’excellentes evaluations internationales, la therapie interpersonnelle est une psychotherapie breve, structuree, en 12 a 16 seances a un rythme hebdomadaire, centree sur un domaine interpersonnel problematique actuel. Quatre ont ete montres comme significativement correles a l’emergence de la depression : le deuil, la transition de role, les conflits et le deficit interpersonnel. Elle a fait les preuves de son efficacite dans le traitement aigu ambulatoire de la depression de l’adulte et de l’adolescent, et plusieurs projets de recherche ont teste sa validite, avec plus ou moins de reussite, dans d’autres contextes, d’autres groupes de sujets, et dans d’autres pathologies psychiatriques. Chez l’adolescent, elle presente un interet indeniable, mais sa forme originale doit etre adaptee aux particularites propres a cette population. Cet article expose des generalites sur la therapie interpersonnelle, puis les elements propres a sa realisation avec des adolescents depressifs [Resume d'auteur]

En 2013, le DSM-5 a propose la creation d'une nouvelle maladie mentale, le Hoarding disorder (HD), qu'on pourrait traduire par le syndrome d'entassement. La semeiologie francaise decrit depuis plusieurs annees un syndrome dans lequel l'entassement est un point important, il s'agit du syndrome de Diogene. Cet article pose les questions de leurs differences et de leurs points communs. Issu des troubles anxieux, et en particulier des troubles obsessionnels compulsifs, le HD s'en est progressivement detache, pour devenir un trouble anxieux individualise. Il se manifeste entre autres par une difficulte majeure a se separer de possessions, qui s'accumulent ainsi, parfois jusqu'a rendre invivable, voire insalubre, le domicile. L'insight dans ce trouble est variable et certains patients peuvent ainsi presenter les criteres diagnostiques du syndrome de Diogene, a savoir l'absence d'appel a l'aide, et un trouble du rapport aux objets, la syllogomanie. Au total, le syndrome de Diogene et le Hoarding disorder pourraient etre deux dimensions d'une meme entite, l'un representant la dimension de salete (squalor) et l'autre la dimension d'entassement (hoarding). Des etudes cliniques sont indispensables pour avancer dans la comprehension de ces troubles et les soins a apporter aux patients. [resume de l'editeur]

We examined the influence of stand structure surrounding individual dominant and codominant trees on leaf area, tree growth, and growth efficiency (stem growth per unit leaf area) in young white spruce ( Picea glauca (Moench) Voss) plantations. Objectives were to (i) test the hypothesis that individual tree volume increment and growth efficiency increase with increasing growing space, and (ii) determine the relative importance of growth efficiency and leaf area to stem volume increment in young spruce following thinning. Growing space was expressed as area potentially available (APA) to each tree. Relative current annual volume increment (annual increment divided by the mean increment for the 3 years immediately preceding thinning) increased linearly with increasing APA 2 and 3 years after thinning, supporting our hypothesis that tree volume increment increases with APA. Growth efficiency however, was not related to APA. Leaf area was positively related to APA 3 years after thinning, and current annual volume increment was related to leaf area. Leaf area per tree increased from 17.8 m 2 to 29.8 m 2 over the 3 years (2011–2013) following thinning and was 16.5–18.7 m 2 for unthinned trees over the same period. Growth efficiency decreased from 1.35 to 0.64 dm 3 m −2 for thinned trees and from 0.74 to 0.55 dm 3 m −2 for unthinned trees from 2010 to 2013. Growth efficiency did not differ between thinned and unthinned trees, but it was significantly lower in year 3 than year 1 after thinning ( p = 0.0178) and significantly lower than the prethinning growth efficiency ( p = 0.0034). Our results show that thinning increased individual tree volume increment by increasing leaf area of remaining trees and not by increasing their growth efficiency.

In the Acadian Forest Region of northeastern North America, forest managers are under increasing public pressure to restore the forest to a more historic, natural condition by reducing in clearcutting and promoting partial-cut treatments that more closely emulate historic, local natural disturbance regimes. However, although numerous studies on the effects of partial-cutting on forest regeneration response have been conducted in surrounding temperate and boreal forest ecosystems, there are few studies that directly explore responses to various forms of harvesting within the Acadian Forest ecosystem, with its unique mixture of northern hardwoods and boreal forest species. Here, we conducted one of the first retrospective studies on forest regeneration following a variety of harvesting methods in the Acadian Forest using univariate and multivariate regression trees to assess regeneration response in 50 naturally-regenerating, harvested forest sites in New Brunswick, Canada. Our study shows that regeneration was highly influenced by harvest type, overstory composition, and environmental conditions as reflected by ecoregion classification. Canopy opening size (as controlled by harvest method) significantly influenced the dominance of regenerating species. The presence of conspecific overstory trees increased the likelihood of their regeneration following disturbance, supporting the direct-regeneration hypothesis, especially for species with limited seed dispersal (e.g., sugar maple (Acer saccharum Marsh.) and American beech (Fagus grandifolia Ehrh.). Despite reported problems elsewhere in eastern North America, neither American beech nor balsam fir (Abies balsamea (L.) Mill.) constituted significant competition for the desired species on a broad scale, but the presence of beech was a significant deterrent for yellow birch (Betula alleghaniensis Britt.).

0, info:eu-repo/semantics/published

Background A novel approach to modelling individual tree growth dynamics is proposed. The approach combines multiple imputation and copula sampling to produce a stochastic individual tree growth and yield projection system. Methods The Nova Scotia, Canada permanent sample plot network is used as a case study to develop and test the modelling approach. Predictions from this model are compared to predictions from the Acadian variant of the Forest Vegetation Simulator, a widely used statistical individual tree growth and yield model. Results Diameter and height growth rates were predicted with error rates consistent with those produced using statistical models. Mortality and ingrowth error rates were higher than those observed for diameter and height, but also were within the bounds produced by traditional approaches for predicting these rates. Ingrowth species composition was very poorly predicted. The model was capable of reproducing a wide range of stand dynamic trajectories and in some cases reproduced trajectories that the statistical model was incapable of reproducing. Conclusions The model has potential to be used as a benchmarking tool for evaluating statistical and process models and may provide a mechanism to separate signal from noise and improve our ability to analyze and learn from large regional datasets that often have underlying flaws in sample design.

Intensive forest management practices can alter forest soil organic matter (SOM) storage (kg C ha − 1 ) due to changes in the environmental variables that control SOM cycling and stability. Here we investigate whether SOM losses are observed three decades following clearcut harvesting in a temperate forest ecosystem that includes the deep mineral soil (to a depth of 50 cm). We compared SOM stored as carbon (C) and nitrogen (N) in paired (35-year-old; 110-year-old reference) Acadian Forest sites that differed only in their time since harvest. We found lower mineral soil carbon (C) and nitrogen (N) storage (27% and 26% respectively), and lower C and N concentrations at the 35-year-old site compared with the 110-year-old reference site. Isotopic compositions of C and N through the soil profile did not provide insight into the dominant mechanisms driving SOM losses at the 35-year-old site in this study. This is the second study to document decreases in mineral soil C and N storage in a red spruce forest within the Acadian Forest Region three decades following clearcut harvesting.

Simultaneous biometric measurements of aboveground net primary production (ANPP) and eddy-covariance measurements of gross primary production (GPP) were made at 18 forest stands with 80 site-years of data across Canada – to assess the fraction of photosynthesis that is used to produce plant tissues and the consistency of carbon allocation patterns across forest ecosystems. The stands included boreal and temperate forests and spanned very young to mature stand ages. Across all sites, ANPP averaged 298 ± 138 g C m−2 yr−1 (mean ± 1 s.d.), with the highest values for temperate white pine plantations (307–630 g C m−2 yr−1) and harvested Douglas-fir stands (219–459 g C m−2 yr−1), and the lowest values for boreal harvested jack pine stands (97–185 g C m−2 yr−1). ANPP more than doubled from newly established (≤12 years) to young (13–25 years) stands, then stabilized in young to mature (≥51 years) stands but with diverging trends among species. Inter-site variations in ANPP and GPP were closely related to site characteristics, in particular, to leaf area index, which explained 66% of the variation in ANPP and 80% of the variation in GPP, and absorbed photosynthetically active radiation, which explained 80% of the variation in ANPP and 82% of the variation in GPP. Both ANPP and GPP were also positively correlated with mean annual air temperature, mean annual precipitation, and total soil nitrogen in the upper 10 cm of the mineral soil. ANPP was strongly, positively correlated with GPP and the ANPP/GPP ratio was relatively constant (0.29 ± 0.06), with no consistent differences among species or age classes. The results support the use of a constant ANPP/GPP ratio as a reasonable assumption in models of forest productivity for boreal and northern temperate forests. A similar conclusion is reached for the NPP/GPP ratio when published values of belowground NPP are considered.

A new stand-level dynamics model based on observed stand growth trajectories is presented. This stand-level dynamics model uses the trajectories of observed plots through Reineke’s quadratic mean diameter-density space to predict the change in quadratic mean diameter, ingrowth and mortality over time. The model uses the collection of observed trajectories as a probability distribution that is used to guide an informed random walk. An imputation model is used to select k nearest neighbors (bandwidth) which are then used to build joint kernel distributions. From these kernel distributions, m random samples (sample intensity) are averaged to predict the change in quadratic mean diameter, ingrowth and mortality. All levels of k tested (10, 20, 30) performed well as long as sampling intensity was above 1. Variability in predictions was reduced at sampling intensities above 1, but no significant differences were visible among sampling intensities 5 and above.

The DØ experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid-argon calorimeters and central muon detector, remaining from Run I, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to DØ. © 2006 Elsevier B.V. All rights reserved.

Fine roots play an important role in forest productivity and carbon cycling, however, little is known about their dynamics during stand development or their response to forestry practices. We used the minirhizotron method to measure fine-root production ( NPP fr ), mortality ( M fr ), and year-end standing crop ( SC fr ) for 5 years at balsam fir ( Abies balsamea (L.) Mill.) stands representing a chronosequence after clearcutting that also incorporated thinning of younger and older stands. We used seemingly unrelated regression to maintain mass balance among components of fine-root dynamics in our investigation of relationships with stand development and responses to thinning. The final statistical model explained 58% of the variation in fine-root dynamics, did not use stand age to explain variations in NPP fr , and used stand age to explain variations in M fr . In the years immediately after clearcutting, SC fr increased rapidly, reaching a maximum in approximately 10 years, and declining slowly thereafter as a stand approached maturity. In the early years as SC fr increased, NPP fr increased and remained approximately constant thereafter. We ascribed the rapid early increase in SC fr to the existence of vigorous advanced growth and high relative fine-root production rates, and the slow decline after reaching a maximum to increasing relative mortality rates. In a pole-stage stand, SC fr recovered approximately 5 years after thinning due to increased relative fine-root production rate and lower mortality rates. In contrast, SC fr did not recover after thinning in a semi-mature stand because relative fine-root production did not increase. Elevated mortality after thinning due to death of root systems of cut trees was observed for several years in thinned stands. The lack of response of fine roots in older thinned stands may limit the response of aboveground components to thinning.

Summary Knowing the abundance of small trees is necessary for accurate calculation of gross production, total carbon and/or biomass of forest stands. The abundance of small trees can also be used to predict ingrowth into larger tree diameter classes. We present a method of predicting numbers of trees in small diameter classes using diameter distributions of larger trees in stands. A truncated two-parameter Weibull distribution was fit to large tree diameters (diameter at breast height (d.b.h.) ≥ 9.0 cm). These parameters were then used to predict the number of small trees in d.b.h. classes smaller than 9.0 cm. Three methods of predicting densities of small trees were used: (1) an extrapolation of the truncated Weibull to a full two-parameter Weibull distribution; (2) a modification of the Weibull using an empirical estimate and (3) a combined approach. While the full two-parameter Weibull distribution generally fitted the distribution of small trees, densities were typically under-predicted. The empirical method (i.e. method 2) produced the best predictions of small tree densities, with a root mean square error of 132 trees h 21 (28 per cent of mean small tree density). Overall, predicting the distribution of small trees using the distribution of large trees worked very well in this study.

We used 15 site-years of minirhizotron observations (1998–2006 at one site; 1998–2000 and 2004–2006 at second site) from two mature balsam fir ( Abies balsamea (L.) Mill.) sites to quantify interannual variability in fine root demography and assess the accuracy of estimates from early years of observation. Annual production varied fourfold at Forêt Montmorency (FM) (5.8–26.5 roots·100 cm–2) and twofold at Green River (GR) (7.2–14.2 roots·100 cm–2). Annual mortality varied more than 30-fold at the two sites (FM: 0.7–23.2 roots·100 cm–2; GR: 0.3–10.9 roots·100 cm–2), year-end standing crops varied two- to eight-fold (FM: 3.6–28.4 roots·100 cm–2; GR 8.5–18.6 roots·100 cm–2), and median life-span of annual cohorts varied from 180 to 540 days at FM and from 350 to 577 days at GR. This variation illustrates that root demography estimates from short-term studies may differ widely from long-term means. Annual mortality and standing crops were lowest in the first year of observation and tended to increase for two or more years at both sites, whereas these trends were not observed for annual production. Our results indicate that minirhizotron tubes must be in place for more than 2 years to accurately estimate fine root demography at balsam fir sites.

We measured respiratory fluxes of carbon dioxide by aboveground tree components and soil respiration with chambers in 2005 and scaled up these measurements over space and time to estimate annual ecosystem respiration (R(e)) at a mature black spruce (Picea mariana (Mill.) B.S.P.) ecosystem in Quebec, Canada. We estimated periodic annual net primary production (NPP) for this ecosystem also. R(e) was estimated at 10.32 Mg C ha(-)(1) year(-)(1); heterotrophic respiration (R(h)) accounted for 52% of R(e) and autotrophic respiration (R(a)) accounted for the remainder. We estimated NPP at 3.02 Mg C ha(-1) year(-1), including production of bryophyte biomass but not including shrub NPP. We used these estimates of carbon fluxes to calculate a carbon use efficiency [CUE = NPP/(NPP + R(a))] of 0.38. This estimate of CUE is similar to those reported for other boreal forest ecosystems and it is lower than the value frequently used in global studies. Based on the estimate of R(h) being greater than the estimate of NPP, the ecosystem was determined to emit approximately 2.38 Mg C ha(-1) year(-1) to the atmosphere in 2005. Estimates of gross primary production (GPP = NPP + R(a)) and R(e) differed substantially from estimates of these fluxes derived from eddy covariance measurements during 2005 at this site. The ecological estimates of GPP and R(e) were substantially greater than those estimated for eddy covariance measurements. Applying a correction for lack of energy balance closure to eddy covariance estimates reduces differences with ecological estimates. We reviewed possible sources of systematic error in ecological estimates and discuss other possible explanations for these discrepancies.

The emergence of new devices and technologies introduces new trends and design issues for optical transport networks. The higher performance of transmission and switch systems enables the reduction of optoelectronic conversions in intermediate nodes with the introduction of transparency in the network. Simultaneously, the system of Automatic Switched Optical Networks (ASON) describes the rules for the construction of a network enabling cost reduction, above all for maintenance, and fast and automatic reconfiguration. Two axes have to evolve to make possible all these proprieties: the control plane and its relative set of protocols, to manage the network working for the network automation, and also the systems and tools enabling transparency and reconfigurability. In this article we focus on the second axis applied to an automatic transparent network. To cite this article: A. Morea et al., C. R. Physique 9 (2008).

We are investigating responses of ecosystem processes to climate and silvicultural practices to improve predictions of climate change impacts and to assess opportunities for adapting to impending changes. This involves studies of fine- and coarse-root dynamics, the distribution of net primary production between aboveground and belowground components of balsam fir (Abies balsamea [L.] Mill.) and sugar maple (Acer saccharum [Marsh.]) and photosynthetic capacity of balsam fir during winter and spring. Ongoing studies are described. Key words: fine roots, coarse roots, conifer, hardwood, net primary production, biomass dynamics, photosynthetic recovery, root lifespan, root turnover, soil temperature

Photosynthesis in balsam fir (Abies balsamea (L.) Mill.) was measured in the field at two locations in New Brunswick, Canada from late winter to late spring in 2004 and 2005. No photosynthesis was detectable while the soil remained below 0 degrees C throughout the rooting zone. In both years, photosynthesis began once soil temperature rose to 0 degrees C. In potted seedlings in growth chambers, there was no photosynthesis at an air temperature of 10 degrees C if the pots were frozen. These findings suggest that, once air temperatures permit photosynthesis, it is the availability of unfrozen soil water that triggers the onset of photosynthesis. In the field, full recovery of photosynthetic capacity following the onset of soil thaw was dependent on air temperature and took 5 weeks in 2005, but 10 weeks in 2004. There were two substantial frost events during the recovery period in 2004 that may explain the extended recovery period. In 2005, recovery was complete after the accumulation of 200 growing degree days above 0 degrees C after the start of soil thaw.

Root systems of 31 balsam fir ( Abies balsamea (L.) Mill.) trees were excavated at five sites in central New Brunswick. Sites ranged from 10 to >80 years in stand age; most had been thinned at least once, and densities ranged from 750 to 44 000 trees·ha–1. The relationship between diameter at breast height and coarse root biomass in the present investigation was similar to one reported for balsam fir in northern New Brunswick but differed from two other published biomass equations. Coarse root biomass per hectare ranged from 3 to 30 Mg·ha–1 among studied sites. Coarse root biomass in the smaller root diameter classes was similar at all sites, but biomass in diameter classes >50 mm increased with stand age. Precommercial thinning added 3 Mg coarse root biomass·ha–1 to the detrital pool. The ratio of coarse root biomass to stem biomass averaged 0.36 (±0.02 SE). These results show that there is more belowground biomass in balsam fir ecosystems than would be expected from the generic ratio of belowground to aboveground biomass often applied to coniferous ecosystems, pointing to a need for using ratios that are more specific.

Aboveground net primary productivity (ANPP) was measured in three balsam fir (Abies balsamea (L.) Mill.) forests on a climatic transect extending from southern New Brunswick ("warm" study area) to central Quebec ("cool" study area). Annual foliar production was estimated with a relationship between cross-sectional area at breast height of the current-year annual xylem ring and the mass of current-year foliage, using data obtained by harvesting trees at the beginning of the study. This relationship differed among study areas. Annual branch production was determined from annual foliar production and the ratio of annual branch production to annual foliar production. The ratio of branch to foliar production was estimated from intensive measurement of a sample of branches collected at the end of the study period; it varied among years but was similar for all study areas. ANPP was 3.36 Mg C·ha–1·year–1 at the warm study area, 3.73 Mg C·ha–1· year–1 at the mid-transect study area, and 3.04 Mg C·ha–1·year–1 at the cool study area. These estimates of ANPP were greater than those estimated using a conventional method of summing up increment and litterfall. On average, the conventional estimate of ANPP was 83% of the estimate using relationships described above. Because net ecosystem productivity is the difference between NPP and heterotrophic respiration, a 17% underestimate of NPP can have a substantial effect on the estimate of carbon-sink activity of a forest.

We investigated the sensitivity of the Landsat enhanced wetness difference index (EWDI) to temporal resolution in detecting forest harvesting and silvicultural activities in the Fundy Model Forest in southern New Brunswick. The severity of disturbance was underestimated in the multiyear EWDI because of regrowth and natural variability. In certain instances the severity of disturbance was overestimated with an annual EWDI; for example, a herbicide application in a young stand could have an annual wetness difference approximately equal to that of a forest clearcut. In general, we found annual EWDI differences to be more accurate than multiyear differences in detecting change. The sensitivity of satellite image change detection techniques to temporal resolution must be considered when national or international protocols are developed to provide input to forest monitoring or carbon accounting efforts.

Soil respiration (rs), soil temperature (Ts) and volumetric soil water content were measured in a balsam fir (Abies balsamea (L.) Mill.) ecosystem from 1998 to 2001. Seasonal variation in root and microbial respiration, and covariation in abiotic factors confounded interpretation of the effects of Ts and soil water potential (Psis) on rs. To minimize the confounding effect of temperature, we analyzed the effect of Psis on rs during the summers of 1998-2000 when changes in Ts were slight. Soil respiration declined 25-50% in response to modest water stress (minimum Psis of -0.6 to -0.2 MPa), and between years, there was substantial variation in the relationship between rs and Psis. In the summer of 2000, 2-m2 plots were subjected to drought for 1 month and other plots were irrigated. The relationship between summertime rs and Psis in the experimental plots was similar to that estimated from the survey data obtained during the same summer. In late spring and early autumn of 2001, 2-m2 trenched and untrenched plots were subjected to drought or exposed to rainfall. It was dry in the early autumn and there was severe soil drying (Psis of -10 MPa in untrenched plots and -2 MPa in trenched plots). In spring, rs in untrenched plots responded more to modest water stress than rs in trenched plots, indicating that root respiration is more sensitive than microbial respiration to water stress at this time of year. The response to abiotic factors differed significantly between spring and autumn in untrenched plots but not in trenched plots, indicating that root activity was greater in early autumn than in late spring, and that roots acclimated to the sustained, severe water stress experienced before and during the autumn.

Summary • To determine if stem respiration (r) varied during cambial reactivation, r was measured during March–July in untreated trees and seedlings, debudded seedlings and girdled seedlings of white ash (Fraxinus americana), red maple (Acer rubrum) and balsam fir (Abies balsamea). • The r was measured using an infrared gas-analysis system. Cambial reactivation was monitored by light microscopy. • After increasing modestly about the time of cambial cell swelling, r declined to a minimum for several weeks and then increased markedly as rapid xylem production (XP) began. Growth respiration (Rg) over the experimental period was positively correlated with XP over the same time span, with differences in wood anatomy and XP-measurement method accounting for differences among species. A weak, positive trend was observed between maintenance respiration (Rm) and XP. Rm varied among species. • The marked springtime increase in r is a nondestructive marker for the onset of rapid XP. Measurements of r made after cambial cell swelling and before rapid XP are appropriate for applying the mature-tissue method to estimate Rg and Rm. Rg reflects XP, particularly the width of differentiating xylem.

To investigate the effect of defoliation by the balsam fir sawfly (Neodiprion abietis) on current-year growth and photosynthesis, all 1-year-old and older foliage were removed by manual clipping before the start of the growing season from balsam fir seedlings cultivated at two levels of fertilization. Measurements carried out late in the same growing season showed that both defoliation and withholding fertilizer reduced current-year foliar dry weight, shoot length, needle size, and stem xylem radial width, as well as total foliar dry weight, and root dry weight. Defoliation increased the projected area to weight ratio, nitrogen concentration, net photosynthetic rate per unit of dry weight, and ratio of photosynthesis to internal CO2 concentration in current-year needles. In contrast, withholding fertilizer did not alter the projected area to weight ratio and decreased the nitrogen concentration, net photosynthetic rate per unit of dry weight, and ratio of photosynthesis to internal CO2 concentration. Both defoliation and withholding fertilizer also decreased the number of current-year needles produced in the growing season following treatment. The results indicate that (1) the reduction in total photosynthesizing biomass caused by removing old foliage is much greater than the biomass of old foliage removed due to decreased production of current-year foliage, and (2) old foliage removal stimulates net photosynthesis in current-year shoots, probably by improving foliar nitrogen relations. Removing old foliage reduced the total photosynthesizing biomass more, and stimulated net photosynthesis of remaining foliage less, than the removal of current-year foliage measured in earlier studies, which helps explain why tree recovery is slower following defoliation by the balsam fir sawfly than after spruce budworm (Choristoneura fumiferana) attack.

Concern exists that soil respiration (Rs) will increase with global warming, thereby reducing the sink strength of forest ecosystems for carbon (C) or making them sources. We measured Rs at three balsam fir (Abies balsamea (L.) Mill.) sites on a climatic gradient from 1997 to 2000 to assess potential responses to global warming. Mean annual Rs varied from 0.67 kg C·m-2·year-1 at the cool site, to 1.19 kg C·m-2·year-1 at the midtransect site, to 1.52 kg C·m-2·year-1 at the warm site. Trenched plots were installed in 1999 to partition Rs into root respiration (Rr) and heterotrophic respiration (Rh). Differences in trenched-plot respiration (Rt) among sites were much less than differences in Rs, because trenching reduced Rs at the warm site more than at the cool site. Annual Rt was 22% less than annual Rs at the cool site, 36% less at the midtransect site, and 50% less at the warm site. After making adjustments for extraordinary decomposition of killed roots in trenched plots, it was estimated that annual Rh varied little among sites (0.40 kg C·m-2·year-1 at the cool site to 0.54 kg C·m-2·year-1 at the warm site), but annual Rr varied substantially among sites (0.24 kg C·m-2·year-1 at the cool site to 0.98 kg C·m-2·year-1 at the warm site). We conclude that Rs varied among sites, because climatically driven differences in primary productivity caused greater Rr and greater detrital production for Rh.

Geometric optical reflectance models provide a physical linkage between image data and forest structure. We developed a "multiple-forward-mode" pseudoinversion modeling approach to produce structural lookup tables for Landsat Thematic Mapper images before and after 1993 partial harvests in New Brunswick, Canada. Modeling results validated for stand density, crown radius, and stem counts enabled simple forest structural change detection.

Satellite remote sensing has long held promise as a powerful method of detecting forest canopy changes and mapping landscape structure over vast, often multi-jurisdictional forest areas. Landsat Thematic Mapper (TM) spectral response, for example, can be related accurately to changes in physiology and cover at a range of small to intermediate mapping scales. These data have been available continuously for almost 20 years; many areas have earlier satellite image archives stretching back to the 1970s. When considering spatially-explicit changes to landscapes—caused by natural and human disturbances—over this time period, digital, synoptic, and repeatable satellite remotely-sensed data are emerging as the observational media of choice that forest managers must possess and use wisely. In this paper, successful use of satellite remote sensing in two of Canada’s Model Forests is described. First, in the Fundy Model Forest in southeastern New Brunswick, a 15-year TM image sequence was used to detect area changes associated with different harvesting and silvicultural practices. Second, in the Foothills Model Forest in west-central Alberta, grizzly bear habitat maps have been created from multi-scene TM land cover mosaics. These map products constitute critical information on landscape change and configuration required to answer key management questions. The paper concludes with a prognosis for the future role of satellite remote sensing in sustainable forest management as data quality continues to improve (i.e., increasing spatial, spectral, temporal, and radiometric resolutions), and methods are brought into the purview of forest managers and practitioners. Key words: remote sensing, landscape change, forest fragmentation, human disturbance, management information needs, habitat

We used the Landsat Thematic Mapper (TM) enhanced wetness difference index (EWDI) to detect forest changes in the Fundy Model Forest, a large, multi-jurisdictional forest management unit in southeastern New Brunswick. The average annual change on the landscape was approximately 3068 ha over a 15 year interval (1984‐1999). The estimate of total change (almost 50 000 ha) as a percentage of the total Fundy Model Forest available productive forest land (approximately 240 000 ha) translates into a rate of change of approximately 1.3% annually.

Depression disorder may become the first cause of morbidity by 2030, according to the World Health Organization. It is actually one of the main causes of disease and handicap in children aged from 10 to 19. The major risk is suicide, whose prevalence is estimated, in France, around 6.7 for 100,000, which is probably underestimated. At present, the discussions about prescription of antidepressants in an adolescent's depression remain intense which is why psychotherapy becomes the first choice of treatment. We propose here to present one of them, Interpersonal PsychoTherapy (IPT), which remains largely unknown in France, and its adaptations in the adolescent population.IPT is a brief psychotherapy, structured in twelve to sixteen sessions, which was created by Klerman and Weissman in the seventies inspired by the biopsychosocial model of Meyer, interpersonal theory of Sullivan, and attachment theory of Bowlby. It is divided into three parts: the initial phase, the intermediate phase, and the termination phase.IPT was adapted for adolescents by Mufson in 1993, but a few modifications must be considered. Parental implication is the first. Indeed, parents, rather than the adolescent, often ask for the consultation; but it is the latter who benefits from the therapy. Parents may be met at some point in the therapy, for example between each phase and at the end. The initial phase is very close for the adolescent as for the adult; but the therapist must be careful about employing the "sick role" which can be used by the adolescent to avoid school, and as a consequence, to exacerbate the interpersonal deficit. The intermediate phase focuses on one of the four interpersonal issues: complicated bereavement, role transition, interpersonal role disputes, and interpersonal deficit. Complicated bereavement may become problematic when prolonged or when the adolescent had complicated relations with the deceased. The therapist essentially works on emotion verbalization. The role of transition is very common during adolescence: children become adults, they pass from high school to college, or their parents get divorced, etc. The patient and the therapist work on giving up the old role with its emotional expression (guilt, anger, and loss), and acquiring new skills, and identifying positive aspects of the new role. Interpersonal role disputes are common during adolescence, with parents or teachers for example. To determine a treatment plan, the therapist may first determine the stage of the role dispute, among impasse, renegotiation, or dissolution, and then work on the communication mode of the patient. At the least, the interpersonal deficit may be the most difficult area to work on because of the risk of psychiatric comorbidity. The therapist must be especially careful about anxious disorder which may complicate the psychotherapy and for which IPT is not the best therapy. The termination phase focuses on the new skills and abilities and works on the future without therapy. IPT is one of the psychotherapies recommended in the treatment of depression disorder in the international recommendations. But in France, all psychotherapies are considered equally. This may be a consensual approach, but the authors wonder if it is the best, especially to motivate research in the psychotherapy field.Finally, IPT has been developed in other indications in the past years, and many others are presently in research projects: depression during pregnancy, prevention of depression relapse, eating disorders, attention deficit and hyperactivity disorder, self-harm for example.Its validity, simplicity and efficacy should stimulate psychiatrists and residents to train themselves to IPT.

In 2013, the American Psychiatric Association published the DSM-5. In this new version, new diagnoses were proposed including the Hoarding disorder. In the French semeiology, the Diogenes syndrome is described, among other symptoms, by a pathological tendency to accumulate objects called syllogomania which is very close to hoarding. This paper explores the similarities and differences between the two syndromes.The Diogenes syndrome was first described in 1966 but was officially named for the ancient Greek philosopher in 1975 by Clark. Its frequency is around five for 100,000 persons. Many aetiologies have been known to be associated with the Diogenes syndrome: schizophrenia, dementia - especially frontotemporal type, anxiety disorders, mood disorders, and substance abuse - especially alcohol abuse. The diagnostic requires one major criterion, the inability to ask for medical or social help, and one of three minor criteria: a pathological relationship to the body, which leads to somatic illness; a pathological relationship to the society, which leads to a progressive exclusion from it; and finally, a pathological link with objects. This last criterion is very interesting because it is closely related to the Hoarding syndrome: indeed, patients with syllogamania, as also named, have a tendency to hoard every object they find. At the end, their homes are full of useless objects, and some living places can be unusable because they are cluttered and congested. This last point is similar to the definition given in the DSM-5 for the Hoarding disorder which describes a persistent difficulty parting with possessions; distress associated with discarding possessions; and accumulations that congest and clutter active living areas. The Hoarding disorder was first part of the Obsessive and compulsive disorders, but it has progressively appeared that it could be individualized with its own prevalence of 2.3% to 14% lifetime. Genetical studies have shown that at least 50% of patients suffering from excessive hoarding had a relative with a dimension of hoarding. Finally, Mattaix-Cols et al. decided to create a new syndrome in the DSM-5, and the Hoarding disorder was born.The discussion begins with relationships between the Hoarding disorder and the Diogenes syndrome. A patient with hoarding, and a poor insight, could be very isolated, and could persist in a lack of calling for help, because of not being aware of his pathology. Thus, it could be diagnosed as a Hoarding syndrome with a poor insight, or as a Diogenes syndrome, with the first major criterion (lack of calling for help) and one of the three minor criteria, the syllogomania, or hoarding. Moreover, some authors have described old people living for many years with a tendency to hoard. Progressively, some of them had a congested and cluttered home, and a few were living in squalor, a description very close to the Diogenes syndrome. Finally, we discuss the comorbidity of Hoarding disorder and Diogenes syndrome. In particular, the first one is associated with Attention deficit and hyperactivity disorders; and some authors also described the links between ADHD, bipolar disorder and frontotemporal dementia which is one of the aetiologies of the Diogenes syndrome. A psychodynamic model in which ADHD, Hoarding disorder and Diogenes syndrome are linked can be imagined, and the last one could be an overlooked evolution of the two first syndromes.In conclusion, we can imagine a dimensional model, based on two dimensions: hoarding and squalor. Hoarding disorder is the major expression of the first dimension, and Diogenes syndrome the major expression of the second. Both of them could be a different expression of one central aetiology. More studies are needed to complete this vision.

To determine the impact of altering the sink:source balance on gas exchange rates in 1-year-old foliage of balsam fir (Abies balsamea (L.) Mill.), seedlings were either debudded before the growing season began or left intact. To assess alternative explanations for the observed photosynthetic response, additional seedlings were variously root pruned, shaded, drought stressed or deprived of fertilizer in combination with debudding. Foliar gas exchange rates and carbohydrate concentrations, xylem water potential and current-year growth were measured on three occasions spanning the shoot extension period. In addition, growth, foliar concentrations of chlorophyll, nitrogen, phosphorus and potassium, chlorophyll fluorescence and photosynthetic rate at different CO 2 concentrations were determined 1 month after shoot extension ceased. Debudded seedlings had higher photosynthetic rates than budded seedlings, and the difference increased as the growing season progressed. We observed no evidence that debudding increased photosynthetic rate by improving water relations or by reducing foliar carbohydrate concentrations. Debudding increased foliar concentrations of nitrogen, phosphorus, potassium and chlorophyll, as well as quantum yield and photochemical quenching as determined by chlorophyll fluorescence measurements. Therefore, we conclude that debudding increased the photosynthetic rate by increasing the allocation of nutrients to 1-year-old foliage, thereby enhancing the amount or activity, or both, of photosynthetic enzymes, as well as increasing chlorophyll concentration.

RESUMEOn decrit des zones de coupes a blanc et de coupes partielles ainsi que les conditions sylvicoles des peuplements forestiers au Nouveau-Brunswick au cours d'une periode d'un an (1997–1998) au moyen de l'interpretation visuelle des differences observees suite a l'application de la transformation «Tasseled Cap» sur deux images Landsat Thematic Mapper. Une image rehaussee des differences d'humidite (EWDI) a ete utilisee pour creer des exemples de changements relies a des conditions de changements connues au sol; nous avons interprete des patrons distinctifs dans les compositions colorees normales et l'image EWDI associes avec les coupes a blanc, les coupes progressives et les coupes d'ensemencement, les coupes par bandes et les coupes associees au jardinage par groupe, et les eclaircies precommerciales et commerciales. Notre interpretation suggere que ces traitements au niveau des peuplements forestiers et les patrons spectraux qu'ils entrainent pourraient servir de base pour le developpement d'une met...

Un programme informatique, le programme PUP (Polygon Update Program), a ete ecrit en langage AML (ARC/INFO Macro Language) pour faciliter l'integration dans un systeme d'information geographique (SIG) d'inventaire forestier d'images satellite classifiees des changements dans le paysage au Nouveau-Brunswick, Le code accepte les attributs definis par l'utilisateur et maintien un identificateur unique de polygone comme variable, le polyid, tout en convertissant les fichiers vectoriels SIG pour superposition sur l'image satellite dans un format de grille commun. La couche polyid est essentiellement une version sur grille des identificateurs des polygones du SIG fournissant un contexte spatial (un polygone et les attributs associes) aux valeurs de pixels superposees. Les donnees image classifiees sont lues et une base de regle est invoquee pour determiner la correspondance entre les attributs des polygones de la grille dans le SIG et la classification de l'image. Le programme resume les changements a l'interieur des polygones en fonction de la logique de la decomposition polygonale definie precedemment. Il est possible de reporter une etiquette dans une table d'attributs pour indiquer l'ampleur du changement detecte. La mise a jour est resumee en termes de polyid, de code d'espece et de superficie de chaque peuplement forestier selon trois classes (faible, modere, severe), Le programme inclut une interface graphique pour l'utilisateur et la capacite de generer des fichiers detailles d'exportation. Un exemple est donne pour illustrer une methodologie et l'elaboration de la mise a jour des donnees d'inventaire forestier.

Resumen Las malformaciones congenitas de la pared toracica que se presentan con mayor frecuencia son el torax en embudo y, en menor medida, el torax en quilla. La ausencia de alteraciones funcionales cardiacas o respiratorias y la agravacion progresiva de la malformacion durante el crecimiento son las razones que llevan cada vez mas al cirujano, ya sea plastico, pediatrico o toracico, a escoger la solucion de correccion mediante endoprotesis a medida. Esta tecnica parece preferible y menos agresiva que las tecnicas radicales de osteocondroplastia modelante o de reseccion del plastron esternocondral con reemplazo por placa protesica. En este capitulo se describen e ilustran las diferentes formas clinicas de las malformaciones toracicas, asi como su implicacion psicologica, que a veces es muy importante, e incluso la unica verdadera indicacion de esta correccion puramente morfologica. Se detallan las modalidades tecnicas de realizacion de la endoprotesis a medida, asi como las tecnicas de colocacion en posicion retromuscular segun la forma clinica y el sexo. Los resultados cosmeticos mejoran con la colocacion en posicion retropectoral y con la calidad de la endoprotesis. En un futuro proximo, la realizacion de maquetas por prototipificacion rapida a partir de imagen de escaner 3D aportara una precision imposible de obtener con el molde externo. La simplicidad de esta operacion gracias a un trabajo multidisciplinario proporciona resultados casi siempre satisfactorios con ausencia de morbilidad. Los unicos inconvenientes postoperatorios pueden ser los derrames de Morel-Lavallee, bastante frecuentes, y una molestia mecanica durante los grandes esfuerzos causada por la anchura o el peso de la endoprotesis.

Although research with digital airborne remote sensing data has been undertaken in different ecoregions to classify forested areas, the potential role of such imagery in deriving information to assist forest management has not yet been fully defined. The objective of this study was to determine the extent that the addition of texture could improve spectral classification of high spatial resolution images (pixel size 1m). These images represented pure and mixed wood forest stands from ecoregions in Alberta and New Brunswick, Canada. This study employed a judicious, selective application of texture to stands within a hierarchical classification framework. In Alberta, the addition of texture made a modest improvement in classification accuracy from 60% to 65%. In New Brunswick, the application of texture to selected land cover types resulted in an overall 12% improvement in classification accuracy. The addition of image texture increased classification accuracy for high spatial detail imagery relative to low...

Net primary production (NPP) and growth efficiency (wood growth per leaf area) decline with stand age for forest ecosystems. Three hypotheses have been suggested: high respiration to photosynthesis ratios, hydraulic limitations on water transport in trees, and nutrient limitations of photosynthesis. Recent work indicates that hydraulic or nutrient limitations probably are the mechanism underlying the decline of growth efficiency in Douglas fir (Pseudotsuga menziesii ) and lodgepole pine (Pinus contorta), both of which are native to western North America. However, balsam fir (Abies balsamea) grows in the cool-humid boreal forest and has very high stem respiration rates, suggesting that the mechanism may be different. We predicted measured aboveground NPP of 24 out of 25 balsam fir stands reasonably well. These stands were selected for having large differences in leaf area index and wood mass. Simulations indicate that increased wood respiration is the major factor causing the decline of NPP and growth efficiency with stand age; a secondary factor for mature stands is nitrogen limitation. For simulations in which balsam fir was fertilized, final growth efficiency was less than that of unfertilized forest stands because of increased stem respiration. From values in the literature, we calculated the potential difference conductance to water flow in the xylem from the soil to the leaves for a mean tree in each stand. Twigs had the smallest conductance; however, because the twigs conductances are added in parallel, the bole was the smallest conductance in the series: bole, branch and twigs. The overall drop of water potential with very high transpiration flux densities was generally less than 2.5 MPa. Therefore, we conclude that, for balsam fir, the decline in NPP and growth efficiency with stand age may be caused by the high respiration to photosynthesis ratios. This conclusion differs from recent work, so there is not a single unifying mechanism of age-related decline for all forest ecosystems. © 1999 Elsevier Science B.V. All rights reserved.

ECOLEAP is a Canadian Forest Service research project that is aimed at improving our understanding of the environmental controls on boreal and sub-boreal forest productivity and at developing tools for predicting stand-level forest productivity over large areas. This interdisciplinary project combines, in a coordinated manner, ecophysiological and soils research, remote sensing research, development of scaling up procedures and process modelling of net primary productivity on a common set of field sites. The process research is carried out in different forest types across large climatic and productivity gradients. Remote sensing provides timely stand information such as composition, leaf area, and absorbed radiation that are not currently available in existing spatial databases. A geographic information system is used to integrate the diverse sources of data. Models serve both as integrators of knowledge and as vehicles for the transfer of the information and methodologies to resource managers. Currently there are three interrelated modelling exercises being carried out within ECOLEAP to address different objectives of the project: an empirical, spatially explicit model of site index, a site-specific process model of productivity, and a spatially explicit process model of productivity. Application of the spatially explicit models will be conducted on extensive pilot regions, the first of which is located north of Quebec City. Key words: modelling, GIS, remote sensing, Canadian Forest Service

L’internat est une période de stress chronique élevé pour les étudiants en médecine et des travaux récents révèlent une prévalence importante des trouble psychiatriques au cours de cette période [1,2]. L’Association française fédérative des étudiants en psychiatrie (AFFEP) a mené une enquête afin de faire un état des lieux sur la prise en charge des internes de psychiatrie en souffrance psychologique au cours de leur cursus. Trois groupes ont été interrogés : les référents AFFEP, qui représentent les internes de psychiatrie dans chaque subdivision, les coordinateurs locaux et interrégionaux du DES de psychiatrie et du DESC de psychiatrie de l’enfant et de l’adolescent. Entre 2013 et 2015, 86 internes ont présenté des difficultés psychologique soit environ 4 % des internes. Cela s’est principalement traduit par des difficultés ou un absentéisme en stage, la mise en arrêt de travail, et quelques rares cas de suicides ou tentatives de suicide ont été décrits. Les premières personnes à signaler les difficultés étaient majoritairement le médecin chef de service, l’interne lui-même ou son co-interne. Une fois les difficultés signalées, des mesures professionnelles étaient mises en place dans 35 % des cas, et 15 % des internes concernés bénéficiaient de soins. La médecine du travail était peu sollicitée, tandis que le coordinateur local, les co-internes, et l’association locale représentaient les principaux intervenants. Pour tous, ce sont les coordinateurs locaux qui sont jugés les intervenants les plus légitimes dans ces situations. Les dispositifs d’évaluation de la santé des internes, en particuliers les comités médicaux, étaient peu connus des référents même s’ils sont jugés utiles par les internes et les coordinateurs locaux. Du fait de la prévalence importante des internes concernés, de l’hétérogénéité et du manque de prises en charge , il semble crucial de proposer des recommandations consensuelles avec les enseignants universitaires, favorisant le parcours professionnel et l’accès aux soins pour ces internes.

Leaf area index (LAI) currently may be derived from remotely sensed data with limited accuracy. This research addresses the need for increased accuracy in the estimation of LAI through integration of texture to the relationship between LAI and vegetation indices. The inclusion of texture, which acts as a surrogate for forest structure, to the relationship between LAI and the normalized difference vegetation index (NDVI) increased the accuracy of modeled LAI estimates. First-order, second-order, and a newly developed semivariance moment texture are assessed in the relationship with LAI. The ability to increase the accuracy of LAI estimates was demonstrated over a range of forest species, densities, closures, tolerances, and successional regimes. Initial assessment of LAI from spectral response over the full range of stand types demonstrated the need for stratification by stand type prior to analysis. Stratification of the stands based upon species types yields an improvement in the regression relationships. For example, deciduous hardwood stands, spanning an LAI range from ≈1.5 to 7, have a moderate initial bivariate relationship between LAI and NDVI at an r 2 of 0.42. Inclusion of additional texture statistics to the multivariate relationship between LAI and NDVI further increases the amount of variation accounted for, to an R 2 of 0.61, which represents an increase in ability to estimate hardwood forest LAI from remotely sensed imagery by approximately 20% with the inclusion of texture. Mixed forest stands, which are spectrally diverse, had an insignificant initial r 2 of 0.01 between LAI and NDVI, which improved to a significant R 2 of 0.44 with the inclusion of semivariance moment texture.

Ecosystem models can be used to estimate potential net primary production (pNPP) using GIS data, and remote sensing input of actual forest leaf area to such models can provide estimates of current actual net primary production (aNPP) . Comparisons of pNPP and aNPP for a given site or regional landscape can be used to identify forest stands for different management treatments, and may provide new information on wildlife habitat, forest diversity and growth characteristics. Leaf area estimates may be obtained from satellite imagery through correlation with physiologically-based vegetation indices such as the Normalized Difference Vegetation Index (NDVI). However, in areas with high Leaf Area Index (LAI), vegetation indices usually saturate at leaf areas greater than about 4. In predominantly deciduous (hardwood) and mixedwood stands remote sensing estimates may be influenced by understory and other factors. We examined digital Landsat TM imagery and GIS data in the Fundy Model Forest of southeastern New Bru...