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Showing papers in "Forestry in 2018"


Journal ArticleDOI
01 Apr 2018-Forestry
TL;DR: In this paper, the authors identify and review the effect of management intensity on priority ecosystem services (ES) and identify synergies and trade-offs among ES of different management approaches.
Abstract: Ecosystem services (ES) are the benefits that people receive from ecosystems. Understanding the impact of forest management on their supply can inform policy and practice for meeting societal demand. The objectives of this paper are to identify and review the effect of management intensity on priority ES supply and identify synergies and trade-offs among ES of different management approaches. We review seven priority ES identified from UK land and forestry strategy and policy documents: timber/biomass production, carbon storage, biodiversity, health and recreation, water supply and quality and flood protection. We present a synthesis of the impact of management on relative ES supply. It shows that low intensity management is unsuitable for high biomass production, yet provides high or moderately high levels of other services. Higher intensity management impacts negatively on biodiversity, health and recreation and water supply services. Combined objective forestry provides high or moderately high levels for all services except biomass. We recommend that a diversity of management approaches is needed to maintain multiple ecosystem service provision. The ES framework offers opportunities to forest management by revealing areas of conflict or co-production and potential trade-offs that may arise from adjusting management intensity.

54 citations


Journal ArticleDOI
01 Jan 2018-Forestry
Abstract: This work was supported by the Department for Environment, Food and Rural Affairs (Defra) as part of the Future Proofing Plant Health (FPPH) project. In addition, R.J.A.B. was partly supported by Living with Environmental Change (LWEC) Tree Health and Plant Biosecurity Initiative - Phase 2 grant BB/L012162/1, funded jointly by the Biotechnology and Biological Sciences Research Council, Defra, Economic and Social Research Council, Forestry Commission, Natural Environment Research Council and the Scottish Government.

29 citations


Journal ArticleDOI
01 Jan 2018-Forestry
TL;DR: In this article, a method for assessing windstorm damages in forest landscapes based on a two-stage sampling strategy using single-date, post-event airborne laser scanning (ALS) data is presented.
Abstract: One of many possible climate change effects in temperate areas is the increase of frequency and severity of windstorms; thus, fast and cost efficient new methods are needed to evaluate wind-induced damages in forests. We present a method for assessing windstorm damages in forest landscapes based on a two-stage sampling strategy using single-date, post-event airborne laser scanning (ALS) data. ALS data are used for delineating damaged forest stands and for an initial evaluation of the volume of fallen trees. The total volume of fallen trees is then estimated using a two-stage model-assisted approach, where variables from ALS are used as auxiliary information in the difference estimator. In the first stage, a sample of the delineated forest stands is selected, and in the second stage the within-stand damages are estimated by means of line intercept sampling (LIS). The proposed method produces maps of windthrown areas, estimates of forest damages in terms of the total volume of fallen trees, and the uncertainty of the estimates. A case study is presented for a large windstorm that struck the Tuscany Region of Italy the night of the 4th and the 5th of March 2015 and caused extensive damages to trees in both forest and urban areas. The pure field-based estimates from LIS and the ALS-based estimates of stand-level fallen wood were very similar. Our positive results demonstrate the utility of the single-date approach for a fast assessment of windthrow damages in forest stands which is especially useful when pre-event ALS data are not available.

26 citations


Journal ArticleDOI
01 Dec 2018-Forestry
TL;DR: The DART-TOFMS technique allows independent verification of claimed identity of certain Cedrela species in timber trade and suggests no potential to discriminate at the studied scale and for the studied species.
Abstract: Combating illegal timber trade requires the ability to identify species and verify geographic origin of timber. Forensic techniques that independently verify the declared species and geographic origin are needed, as current legality procedures are based on certificates and documents that can be falsified. Timber from the genus Cedrela is among the most economically valued tropical timbers worldwide. Three Cedrela species are included in the Appendix III of CITES: C. fissilis, C. odorata and C. angustifolia (listed as C. lilloi). Cedrela timber is currently traded with false origin declarations and under a different species name, but tools to verify this are lacking. We used Direct Analysis in Real Time Time-of-Flight Mass Spectrometry (DART-TOFMS) to chemically identify Cedrela species and sites of origin. Heartwood samples from six Cedrela species (the three CITES-listed species plus C. balansae, C. montana and C. saltensis) were collected at 11 sites throughout Bolivia. Mass spectra detected by DART-TOFMS comprised 1062 compounds; their relative intensities were analysed using Principal Component Analyses, Kernel Discriminant Analysis (KDA) and Random Forest analyses to check discrimination potential among species and sites. Species were identified with a mean discrimination error of 15–19 per cent, with substantial variation in discrimination accuracy among species. The lowest error was observed in C. fissilis (mean = 4.4 per cent). Site discrimination error was considerably higher: 43–54 per cent for C. fissilis and 42–48 per cent for C. odorata. These results provide good prospects to differentiate C. fissilis from other species, but at present there is no scope to do so for other tested species. Thus, discrimination is highly species specific. Our findings for tests of geographic origin suggest no potential to discriminate at the studied scale and for the studied species. Cross-checking results from different methods (KDA and Random Forest) reduced discrimination errors. In all, the DART-TOFMS technique allows independent verification of claimed identity of certain Cedrela species in timber trade.

24 citations


Journal ArticleDOI
01 Oct 2018-Forestry
TL;DR: In this article, the authors assess the evidence for successful interventions, based on a critical review of evidence conducted through the EU-funded project SIMWOOD (Sustainable Innovative Mobilisation of Wood).
Abstract: Forests are expected to contribute towards an increase in supply of sustainable renewable materials and energy, which is commonly referred to as ‘wood mobilization’. In Europe, much attention has focused on the gap between wood potentially and actually harvested. This paper assesses the evidence for successful interventions, based on a critical review of evidence conducted through the EU-funded project SIMWOOD (Sustainable Innovative Mobilisation of Wood). Few evaluations are able to report the impact of interventions on the amount of wood harvested in a way that can be attributed unambiguously to the intervention. The review concludes that (1) there is a need to focus less on surveys of constraints and more on real-life interventions and their success or otherwise; (2) more could be learnt from the experience of such interventions, if evaluations were published in the scientific literature, and if qualitative methods were included, to help understand why stakeholders do or do not change behaviours and increase wood harvests; (3) successful interventions are multifaceted (often combining incentives and advice, or farming and forestry, or production and markets) and (4) although experience can be shared effectively between regions, interventions must be tailored to local social, biophysical and political conditions and developed in context.

22 citations


Journal ArticleDOI
01 Jan 2018-Forestry
TL;DR: In this paper, the potential of airborne laser scanning (ALS) to predict diameter distributions in an even-aged plantation of Eucalyptus urograndis in Brazil was examined.
Abstract: This study examines the potential of airborne laser scanning (ALS) to predict diameter distributions in an even-aged plantation of Eucalyptus urograndis in Brazil The single-species plantation conditions allow different modelling alternatives to be compared without the presence of minor tree species or an understory layer affecting the results Three modelling alternatives based on the two-parametric Weibull function form; parameter prediction, parameter recovery and distribution matching were tested with a k-nearest neighbour prediction (k-nn) method We also evaluated a parameter prediction alternative, in which the Weibull distribution was predicted using field attributes The results showed that ALS information can predict diameter distributions with an error margin of slightly more than 10 per cent of the RMSE of the mean of the third power of diameter, and with error index values between 50 and 60 The degree of accuracy was only slightly improved when the Weibull distribution was predicted using field attributes According to the accuracy metrics, the differences between modelling alternatives were minor but parameter recovery and k-nn seem to be the most favourable ALS-based prediction methods To conclude, the results showed a strong relationship between ALS information and diameter distributions in a tropical single-species plantation and we discuss how these results could be applied in other types of forests

21 citations


Journal ArticleDOI
01 Jul 2018-Forestry
TL;DR: In this paper, the authors evaluated the effect of careful logging around small merchantable stems on the growth and some wood quality parameters of black spruce (Picea mariana (Mill.) B.S.P.) and balsam fir (Abies balsamea (L.) mill.) in the boreal forest of Quebec, Canada.
Abstract: Careful logging around small merchantable stems (CLASS) is a partial cutting treatment in which 70–90 per cent of the merchantable volume of uneven-aged, irregular or multi-layered conifer stands is harvested. The decrease in stand density by means of partial cutting is known to induce an increase in residual stem growth, which could also influence wood properties. This research aims to evaluate the effect of CLASS on the growth and some wood quality parameters of black spruce (Picea mariana (Mill.) B.S.P.) and balsam fir (Abies balsamea (L.) Mill.) in the boreal forest of Quebec, Canada. Four uneven-aged black spruce-balsam fir stands were selected for the study and 15 black spruce and 15 balsam fir trees were sampled in each stand, distributed between a treated and a control area. Radial growth, latewood proportion, ring density, tracheid length and the moduli of elasticity and rupture were measured in each tree. A high proportion of residual stems significantly increased their radial growth after CLASS. No significant change was obtained for latewood proportion, average ring density, tracheid length or mechanical properties for black spruce. However, latewood proportion and ring density were significantly reduced in balsam fir after treatment, with no effect on modulus of elasticity or modulus of rupture. When looking at the wood properties comprehensively, a canonical discriminant analysis did not detect any significant difference between the wood properties before and after treatment for either species. This suggests that CLASS can stimulate the radial growth of residual stems with limited short-term effects on wood quality.

17 citations


Journal ArticleDOI
01 Dec 2018-Forestry
TL;DR: In this article, the profitability of uneven-aged management in boreal forests is evaluated using an individual-tree-based model EFIMOD to simulate the dynamics of soil organic matter, resource availability and forest growth.
Abstract: This study evaluates the profitability of uneven-aged management in boreal forests, focusing on Norway spruce (Picea abies (L.) Karst.). An individual-tree-based model EFIMOD is used to simulate the dynamics of soil organic matter, resource availability and forest growth. Considered management scenarios are constructed by varying the harvest interval and intensity (i.e. post-harvest basal area). Bare land, young stand and several uneven-aged managed mature stands are evaluated as initial stand states in the profitability analysis. The profitability of uneven-aged management is compared with traditional even-aged management. Uneven-aged management is profitable under all considered initial stand states and management scenarios with 3 per cent interest rate. Even-aged management is more profitable than uneven-aged management when the initial stand state is bare land or a young stand. The profitability is usually the opposite when uneven-aged managed mature stands are considered as the initial state. This, however, requires that the most profitable steady-state management regime, involving a 10-year harvest interval and 4 m² ha⁻¹ post-harvest basal area, is applied. Conversion of even-aged Norway spruce stand to uneven-aged is financially feasible when the stand structure of the even-aged stand has a wide diameter distribution of standing trees rather than the more restricted range usually associated with conventional management using thinning from below.

15 citations


Journal ArticleDOI
01 Dec 2018-Forestry
TL;DR: In this paper, a survey of members of the public in the state of Victoria in Australia revealed a broader range of core values relevant to forest management than previously recognized: security (safety and stability of society) and hedonism (pleasure and sensory gratification) were expressed in addition to biospheric, altruistic and egoistic values.
Abstract: Managers of public forests are required to balance multiple values of forests. Developing policies to represent these can be impeded by uncertainty regarding how to understand and describe values relevant to forests. This paper addresses one source of ambiguity by examining forest values at two levels of abstraction: Core values of people (principles that guide in life), and valued attributes of forests (qualities of forests important to people). We used in-depth interviews with 36 members of the public in Victoria, Australia to describe the values relevant to forests at both levels.We then examined relationships between values based on a survey of members of the Victorian public (n = 915). Our study revealed valued attributes encompassing natural, production, cultural and experiential categories.We demonstrated a broader range of core values relevant to forest management than previously recognized: Security (safety and stability of society) and hedonism (pleasure and sensory gratification) were expressed in addition to biospheric, altruistic and egoistic values. Associations between core values and valued attributes revealed biospheric values underpin variation in the importance given to production and natural attributes of forests. The core value of security also underpinned multiple valued attributes. By revealing a comprehensive yet succinct range of values associated with forests, this research supports development of forest policy congruent with expectations of society.

12 citations


Journal ArticleDOI
01 Jul 2018-Forestry
TL;DR: In this paper, the effects of early respacing on the density and microfibril angle (MfA) of Sitka spruce (Picea sitchensis [Bong.] Carr.) wood using samples taken from a fully-replicated 57-year-old trial located in Northern Ireland, which had been thinned at age 11 years.
Abstract: Although significant advances have been made in modelling the effects of silviculture on wood properties, few models have been calibrated using data from long-term stand density or respacing experiments. In this study we examined the effects of early respacing on the density and microfibril angle (MfA) of Sitka spruce (Picea sitchensis [Bong.] Carr.) wood using samples taken from a fully-replicated 57-year-old trial located in Northern Ireland, which had been thinned at age 11 years. Using a mixed-effects modelling approach, radial profiles of density and MfA from four different respacing treatments (1.83 m × 3.66 m, 3.66 m × 3.66 m, 3.66 m × 5.49 m and 5.49 m × 5.49 m) were compared with those of timber from an unthinned control (1.83 m × 1.83 m). After accounting for radial position and ring width, we found significant differences in both density and MfA between respacing treatments. Mean predicted values of wood density for rings 40–50 were 400 and 494 kg m⁻³ for the widest respacing treatment and the unthinned control, respectively, and fell between these two extremes for the other respacing treatments. Predicted latewood proportions in ring 50 were 12 and 22 per cent, for the same respacing treatments, respectively. There was some evidence of an age-related decline in wood density in the two narrowest respacing treatments. While there was a significant effect of respacing on MfA variation, the trends between respacing treatments were less apparent. Overall, these results indicate that the timing of respacing treatments is an important consideration in Sitka spruce management; early and severe respacing should be avoided to avoid deleterious effects on wood density and MfA.

12 citations


Journal ArticleDOI
01 Jul 2018-Forestry
TL;DR: In this paper, the authors measured the modulus of elasticity (MOE) and bending strength (Fb) of 819 pieces of visually graded loblolly pine lumber and compared the probability of meeting design values using (1) normal distribution linear and power regression models and (2) binomial distribution logistic regression models.
Abstract: Within-grade variability in mechanical properties for visually graded lumber has led to increased deployment of nondestructive testing (NDT) methods, even though the relationships between static bending and NDTpredicted values are often highly variable. Dynamic modulus of elasticity (MOEdyn) was measured using two acoustic velocity instruments and one transverse vibration instrument, along with specific gravity, for 819 pieces of visually graded loblolly pine lumber. Static modulus of elasticity (MOE) and bending strength (Fb) were measured via destructive testing. The probability of meeting design values was compared using (1) normal distribution linear and power regression models and (2) binomial distribution logistic regression models; the parameters of both models were fit using maximum likelihood estimation. For the normal distribution models, the standard error of the estimate, which ranged from 1.28 to 1.82 GPa for MOE and 4.47 to 5.07 MPa for Fb, was incorporated into predictions in order to calculate the probability of meeting design values. At 50 per cent probability, transverse vibration MOEdyn values of 10.9 (normal) and 11.0 (binomial) GPa would meet the No. 2 MOE design value (9.7 GPa). At probabilities of 75 per cent and 95 per cent, the required values were 12.1 and 13.8 (normal) GPa and 12.0 and 13.5 (binomial) GPa, respectively. The normal and binomial approaches required similar NDT values to meet thresholds, although the advantage of the normal approach is that the regression parameters do not need to be recalculated for each threshold value, but at the expense of increased model complexity.

Journal ArticleDOI
01 Oct 2018-Forestry
TL;DR: Regeneration was surveyed across six mountain ranges, three silviculture treatments and two levels of disease severity in the Southwest US and results may help refine SWWP management guidelines and expand conservation efforts in forests threatened by WPBR.
Abstract: Modelling natural regeneration is complex, and both natural and anthropogenic disturbances can alter forest trajectories. Pinus strobiformis (southwestern white pine, SWWP) is an important component of mixed conifer forests in the Southwest and management recommendations related to natural and planted regenerations are needed to guide conservation of SWWP in the face of an invasive disease (white pine blister rust, WPBR). Regeneration was surveyed across six mountain ranges, three silviculture treatments and two levels of disease severity in the Southwest US. Key findings were: (1) SWWP regeneration in stands with no recent management (<20 years) and high disease severity had unsustainable WPBR infection, (2) SWWP regeneration was less abundant but less likely to be infected in stands with recent management, (3) stands with high disease severity had fewer SWWP seedlings than stands with no or low disease severity and (4) SWWP regeneration densities were best predicted by other understory species abundance. We recommend silviculture treatments that reduce basal area to 9–10 m² ha⁻¹ and leave large canopy openings to enhance natural SWWP regeneration. Without creating conditions for disease-free regeneration to reach reproductive maturity, some stands may lose SWWP as an overstory component. Results may help refine SWWP management guidelines and expand conservation efforts in forests threatened by WPBR.

Journal ArticleDOI
01 Dec 2018-Forestry
TL;DR: In this article, the authors examined methods for combining these two data sources using data from an urban inventory conducted in Austin, Texas, USA, and NFI data collected in the same and surrounding areas.
Abstract: Due to the interest in status and trends in forest resources, many countries conduct a national forest inventory (NFI) To better understand the characteristics of woody vegetation in areas that are typically not forested, there is an increasing emphasis on urban inventory efforts where all trees both within and outside forest areas are measured Often, these two inventories are entirely independent endeavours from data collection through analytical reporting To holistically explore landscape-scale phenomena across the rural-urban gradient, there is a need to combine information from both sources In this paper, methods for combining these two data sources are examined using data from an urban inventory conducted in Austin, Texas, USA, and NFI data collected in the same and surrounding areas Approaches to aggregating areas based on sampling intensity and plot design combinations are of considerable importance for the validity of the estimation An additional complexity can also arise due to temporal discrepancies between the two data sources Thus, it is imperative to accurately identify all the existing sampling intensity/plot design combinations within the population of interest Once this difficulty is surmounted, there still exist aggregation methods that will produce erroneous results Statistically valid variance estimation arises from maintaining independence of the two samples This approach satisfies both the proportional allocation among strata requirement as well as the necessary partitioning of the two plot designs Difficulty in interpretation of results can also be encountered due to differences in measurement protocols across aggregated areas Thus, analysts should have an in-depth understanding of data sources and the differences between them to avoid unintended errors The need for rural-urban assessments are expected to increase dramatically as urban areas expand and issues such as land conversion, wildland fire and invasive species spread become of further importance