Spectral sensitivity in the photodegradation of fir wood (Abies alba Mill.) surfaces: colour changes in natural weathering

Activation spectra of wood under natural irradiation were investigated in detail in this work. The main purpose was to study colour changes on the wood surface over time and into the depth during natural light exposure and thus to further contribute to the optimization of surface-protecting treatments. In a natural weathering test, three 80-μm-thick strips of fir wood forming the surface layer of a wood composite were exposed to light under a series of glass cut-off filters. Samples were withdrawn at intervals and tested for colour changes. Identification of the most detrimental wavebands of light causing photodegradation was performed based on recorded colour changes. With chronological development of exposure, the colour changes shifted ever deeper into the surface and further into the visible region of the spectrum. A relatively narrow waveband from 360 to 435 nm was identified in the activation spectra to be the most active band, causing the greatest proportion of recorded colour changes. However, also visible light of wavelengths up to 515 nm significantly contributed to colour changes of the surface layers.     

A case study of forest management planning using a new heuristic algorithm

We present an approach to generate and evaluate different silvicultural development paths and to optimize the development of a Norway spruce stand, using a long-term planning horizon. To generate a silvicultural path, the maximum stand density was applied. At each thinning event, three possible thinning intensities (10, 20, 30% of the stem number per ha) were randomly chosen. A search algorithm known as modified Accelerated Simulated Annealing (mASA) was used to estimate the optimum combination of stand paths for a given forest as a whole. Production and economic management objectives were considered and then compared. The economic criterion was the Expected Stand Value (ESV) with a 4% discount rate. The generated data set of 38 Norway spruce stands (comprising a total of 123.8 ha) was used in the case study. The result with the best combination of paths was presented in a digitized forest map. Forest management simulation was performed using a specially developed computer program, for a planning horizon of 20 years. The mASA proved to be an effective search method for identifying optimum paths.     

Concept and feasibility study for the integrated evaluation of environmental monitoring data in forests

In the 1970s unexpected forest damages, called “new type of forest damage” or “forest decline”, were observed in Germany and other European countries. The Federal Republic of Germany and the German Federal States implemented a forest monitoring system in the early 1980s, in order to monitor and assess the forest condition. Due to the growing public awareness of possible adverse effects of air pollution on forests, in 1985 the ICP Forests was launched under the convention on long-range transboundary air pollution (CLRTAP) of the United Nations Economic Commission for Europe (UN-ECE). The German experience in forest monitoring was a base for the implementation of the European monitoring system. In 2001 the interdisciplinary case study “concept and feasibility study for the integrated evaluation of environmental monitoring data in forests”, funded by the German Federal Ministry of Education and Research, concentrated on in-depths evaluations of the German data of forest monitoring. The objectives of the study were: (a) a reliable assessment of the vitality and functioning of forest ecosystems, (b) the identification and quantification of factors influencing forest vitality, and (c) the clarification of cause-effect-relationships leading to leaf/needle loss. For these purposes additional data from external sources were acquired: climate and deposition, for selected level I plots tree growth data, as well as data on groundwater quality. The results show that in particular time series analysis (crown condition, tree growth, and tree ring analysis), in combination with climate and deposition are valuable and informative, as well as integrated evaluation of soil, tree nutrition and crown condition data. Methods to combine information from the extensive and the intensive monitoring, and to transfer process information to the large scale should be elaborated in future.

Cryopreservation of yellow-poplar and sweetgum embryogenic cultures

Cryopreservation has become anessential tool for operational application offorest tree embryogenic cultures, due to thelong evaluation periods needed for treesregenerated from these cultures. Fiveyellow-poplar (Liriodendron tulipifera)and seven sweetgum (Liquidambar spp.)embryogenic culture lines werestored in liquid nitrogen for 48 hours, afterwhich they were thawed and tested for regrowthand ability to produce somatic seedlings.Combinations of two sorbitol pretreatments andthree dimethylsulfoxide (DMSO) cryoprotectantlevels were evaluated for their impact onrecovery following cryogenic storage. The bestresults were obtained with 0.4 M sorbitol and5% DMSO, which provided 100% recovery.Somatic seedlings were regenerated from allculture lines and treatments, except for atransgenic sweetgum line.     

First decadal response to treatment in a disturbance-based silviculture experiment in Maine

Disturbance-based silvicultural systems generally seek to promote complex stand structures that are consistent with temporal and spatial patterns of natural disturbance while allowing for the sustainable harvest of timber. Gap-based harvesting systems are commonly used within this framework because they can be designed to approximate the frequencies and spatial patterns of a wide array of disturbance regimes. Patterns in stand-level growth, sapling recruitment and regeneration response were examined for one such gap-based system, the Acadian Forest Ecosystem Research Program (AFERP) in central Maine, that was designed to emulate the annual 1% disturbance frequency typical of the northeastern United States and Canada. A decade after treatment, stand-level differences in basal area growth and density between two gap-based treatments and an unharvested control were not statistically significant, largely due to low replication, but within-stand growth and regeneration responses differed strongly by spatial position relative to harvest gaps. Regeneration of shade-tolerant and intolerant species increased regardless of gap size, likely a response to increasing light availability from canopy openings due to harvesting and mortality. Further, there was evidence of gap size effects on sapling recruitment as large gaps (>1000 m²) favored the growth and survival of mid-successional species such as red maple and white pine, while small gaps (<1000 m²) favored late-succession species such as eastern hemlock and spruce. Overstory growth rates also differed by both species and position relative to harvest gaps with most species growing best in gaps and better along gap edges than in adjacent forest. Notably, overstory growth rates for white pine were not influenced by spatial position. These results suggest harvest gaps may have significant growth and regeneration impacts in adjacent, yet unharvested areas, which could lead to profound differences in forest development over the rotation. Obviously, longer-term studies of gap-based systems are needed to more clearly elucidate these responses.     

Estimating balanced structure areas in multi-species forests on the Sierra Madre Occidental,Mexico

• Introduction   

This study presents a method for estimating the minimum area which exhibits a balanced diameter distribution, and the corresponding number of trees, for different tree species and forest types in the Santiago Papasquiaro region in the State of Durango, Mexico. The balanced structure area is defined as the minimum contiguous area that is required for sustainable management of a multi-sized selection forest. A multi-sized forest represents a balanced structure unit if the relationship between harvest and growth can be maintained, using a defined target diameter distribution and disregarding major natural disturbances. The study is based on 17,577 sample plots in uneven-aged forests, which are selectively harvested by local communities.     

A spatially explicit height�Cdiameter model for Scots pine in Estonia

This contribution presents an approach to model individual tree height?Cdiameter relationships for Scots pine (Pinus sylvestris) in multi-size and mixed-species stands in Estonia using the Estonian Permanent Forest Research Plot Network. The dataset includes 22,347 trees. The main focus of the study was to use an approach that is spatially explicit allowing for high accuracy prediction from a minimum set of predictor variables that can be easily derived. Consequently, the height?Cdiameter relationship is modeled as a function of only the stand quadratic mean diameter (dg) and the plot geographical coordinates. A specific generalized additive model gam is employed that allows for the integration of a varying coefficient term and 2-dimensional surface estimators representing a spatial trend and a spatially varying coefficient term. The high flexibility of the model is needed due to the very few predictor variables that subsume a variety of potential influential factors. Subsequently, a linear mixed model is used that quantifies the random variation between plots and between measurement occasions within plots, respectively. Hence, our model is based on the theory of structured additive regression models (Fahrmeir et al. 2007) and separates a structured (correlated) spatial effect from an unstructured (uncorrelated) spatial effect. Additionally, the linear mixed model allows for calibration of the model using height measurements as pre-information. Model bias is small, despite the somewhat irregular distribution of experimental areas within the country. The overall model shows some similarity with earlier applications in Finland. However, there are important differences involving the model form, the predictors and the method of parameter estimation.     

Proteomic analysis of membrane preparations from developing Pinus radiata compression wood

For coniferous gymnosperms, few data exist as to the contribution of the membrane-associated proteome to cell wall and wood formation. In this study, we begin to address this knowledge deficiency by examining the proteomic profile of Golgi-enriched membrane preparations derived from developing Pinus radiata compression wood. These membrane preparations were generated by a combination of discontinuous sucrose gradient centrifugation and Triton X-114-based phase separation. Fractionation by phase separation removed contaminating proteins associated with the cytoskeleton and enabled the discrimination between soluble and membrane-bound/integral proteins. The proteomic analysis of the resulting aqueous and detergent phases using high-performance liquid chromatography-tandem mass spectrometry resulted in the identification of 175 proteins. The majority of the identified proteins were membrane bound/integral and originated from cellular components such as the nucleus, plastids, endoplasmic reticulum, plasma membrane and Golgi vesicles. On the basis of bioinformatic analysis, many of the identified proteins were predicted to be involved either in the regulation of wood formation or in cell wall biosynthesis, which indicated that the proteomic analysis of non-cytosolic proteins in developing xylem is a useful strategy to investigate the molecular aspects of wood formation in pine.     

Demand for non-timber forest products: Surveys of urban consumers and sellers in Switzerland

In recent years, worldwide socioeconomic, ecological, and cultural changes have led to a paradigm shift in forestry and forest management. Some years ago, most forest enterprises exclusively focused on wood production, whereas today, forest management is expected to be multifunctional and economically as well as socially and ecologically sustainable [Harrison, S., Herbohn, J., Niskanen, A., 2002. Non-industrial, smallholder, small-scale and family forestry: what's in a name? Small-scale Forest Economics. Management and Policy 1 (1), 1–11; Schmithuesen, F., 2004. Forest policy developments in changing societies — political trends and challenges to research. Towards the sustainable use of Europe's forests: Forest ecosystems and landscape research: Joensuu: European Forest Institute, Proc., vol. 49, pp. 87–99]. In this context, non-timber forest products (NTFPs) such as forest honey, mushrooms, or berries could gain importance as an additional source of income for the forestry sector. To assess the market potential of NTFPs in Switzerland, two corresponding surveys were conducted. A consumer survey (N = 897) conducted in six cities in Switzerland investigated the purchase of Swiss NTFPs, consumer preferences, and demand potentials. An additional survey of sellers of NTFPs (N = 105) looked at these aspects from a complementary perspective. The results showed that there is a high esteem and considerable demand potential for such products among urban consumers. Food products were mentioned most frequently. Both consumers and sellers considered quality and environmental friendliness the most important attributes of NTFPs. Structural and organizational innovations and considerable marketing efforts and sales promotion would be required to expand the market for Swiss NTFP, however. Our results indicate that certification of the products' origin, environmental performance, and quality could support such efforts and that recreational and ecological forest services have a synergetic potential for the marketing of NTFPs.     

Intestinal antiinflammatory activity of a lyophilized infusion of Turnera ulmifolia in TNBS rat colitis

Turnera ulmifolia is a plant popularly known in Brazil and South America as chanana. Some species of Turnera are widely used in folk medicine for different types of inflammatory diseases. In this study, the preventive intestinal antiinflammatory activity of a lyophilized infusion obtained from the aerial parts of T. ulmifolia was tested in the trinitrobenzenesulphonic acid (TNBS) model of rat colitis. The results obtained revealed that pretreatment to colitic rats with the extract, at 250 and 500 mg/kg, significantly attenuated the colonic damage induced by TNBS. This beneficial effect was associated with an improvement in the colonic oxidative status, since the infusion prevented the glutathione depletion that occurred as a consequence of the colonic inflammation. On the other hand, this antioxidant activity was confirmed in in vitro studies. In conclusion, the preventive effect exerted by the lyophilized infusion of T. ulmifolia in the TNBS model of rat colitis is probably related to its antioxidant properties, due to its flavonoids content.