Capital Return Rate and Carbon Storage on Forest Estates of Three Boreal Tree Species

In this study, the capital return rate and carbon storage on forest estates with three boreal tree species are discussed. A growth model is applied, along with verified yield models of sawlogs and veneer logs. Using the normal forest principle, thinning schedules and rotation ages maximizing the estate-level capital return rate are clarified. Regeneration expenses are amortized at the end of any rotation. Capitalizations are greater and rotations longer than in recent studies. The capital return rate is a weak function of initial stem count and rotation age but differs by tree species. The initial stem count strongly contributes to biomass stored in trees. Omission of thinnings increases carbon storage very effectively but requires financial compensation. The most promising way of increasing the capital return rate is the reduction of regeneration expenses. Thinnings are triggered by stand volumes of at least 200 m3/ha. The average commercial trunk volume of trees removed in thinnings always exceeds 200 L. Risk aversion theory proposes short rotations and low stem count in seedling planting unless carbon storage compensation exists. Even a small carbon storage compensation justifies increased seedling counts and extended rotations.

Growth and Yield of Three Boreal Tree Species

Growth and yield of boreal tree species are discussed. A growth model is applied, along with verified yield models of sawlogs and veneer logs. Using the normal forest-principle, thinning schedules and rotation ages maximizing the estate-level capital return rate are clarified. Regeneration expenses are amortized at the end of any rotation. Consequently, capitalizations are greater and rotations longer than in recent studies. The capital return rate is a weak function of initial stem count but differs by tree species. The initial stem count strongly contributes to biomass stored in trees. The most promising way of increasing the capital return rate is the reduction of regeneration expenses. Thinnings are triggered by stand volumes of at least 200 m3/ha. The average commercial trunk volume of trees removed in thinnings always exceeds 200 liters. Risk aversion theory proposes short rotations and low stem count in seedling planting unless carbon storage compensation exists.

Diversity of Carbon Storage Economics in Fertile Boreal Spruce (Picea Abies) Estates

A “normal forest”, an idealized estate with a uniform distribution of stand ages, can be used in the study of sustainable management practices. As the normal forest contains a variety of stand ages, the characteristics of the stands can be represented in terms of a “normal stand”, with properties known as a function of age. This paper takes seven never-thinned stands as seven “normal stands”, which describe seven estates of normal forest. The intention is to study the robustness of carbon storage microeconomics to varying estate characteristics. It was found that the economically optimal rotation ages vary. The state sums of volume and capitalization, corresponding to any optimal rotation, also vary significantly. Growth rates vary more than the optimal expected stand volumes. Consequently, any excess volume related to carbon storage adds on to an almost unified basic volume. For all seven normal estates, the most economical way of increasing carbon storage is to increase the size of trees retained in thinning from above.

Financial valuation and the optimal rotation of a fully regulated forest

This paper demonstrates a new approach to identifying and characterizing the optimal number of age classes in a fully regulated (i.e., normal) forest. We introduce an equilibrium condition for the normal forest requiring that it is financially justified to maintain the steady income forest configuration. We apply two valuation approaches to derive the main conclusion that the Faustmann rotation is the optimal harvest age of a normal forest. Both approaches utilize the standard Fisherian method of asset valuation. The first valuation approach imposes a steady income stream requirement, whereas the second approach is free of such a requirement. The second approach can be interpreted as enforcing market discipline on the normal forest configurations in a competitive equilibrium and picking the only normal forest that can be sustained in competitive equilibrium, namely, the forest with the number of age classes corresponding to the Faustmann rotation age. Our results also highlight an alternative way of deriving and interpreting the so-called zero-profit condition that can be applied to determining the optimal number of age classes in a regulated forest.

The Carbon Sequestration Potential of Degraded Agricultural Land in the Amhara Region of Ethiopia

Forests are a key player within the global carbon cycle and reforestation is an important climate change mitigation mechanism. In this study, we identify potentially suitable areas for reforestation to assess the carbon sequestration potential in the highly deforested and degraded Amhara region of Ethiopia. We apply biogeochemical mechanistic ecosystem modelling to predict the amount of carbon that can be potentially sequestered within different time horizons. Since human intervention plays a key role within the Amhara region, three different forest management scenarios and five different rotation periods following reforestation are tested: (i) unthinned; (ii) removal of 5% of the stem carbon every 20 years (thinning 1); and (iii) removal of 10% stem carbon every 20 years (thinning 2), as well as a rotation period of 10, 30, 50, 100, and 150 years. Sustainable management of reforested land is addressed by implementing the so called ‘Normal-forest’ system (equal representation of every age class). This ensures the long term sequestration effect of reforested areas. The study shows that 3.4 Mha (Mha = Million hectare) of land, including bare land (0.7 Mha), grass land (1.2 Mha), and shrub land (1.5 Mha) can be considered as ecologically potentially suitable for reforestation. Assuming a 100 year rotation period in a ‘Normal-forest’ system, this shows that a total net carbon sequestration potential of 177 Tg C (10.8 Tg C in the soil and 165.9 Tg C aboveground; Teragram = 1012 g) is possible, if all 3.4 Mha are replanted. The highest total net carbon sequestration (soil and aboveground) was evident for the Highland-wet agro-ecological zone, whereas the lowest values are typically in the Midland-dry zone. The highest net aboveground carbon sequestration was predicted for reforestations on current grass land and shrub land versus bare land, whereas the highest net soil carbon sequestration was predicted on current bare land, followed by grass land and shrub land.

Diversity and Composition of Ground-Dwelling Beetles in Cold Temperate Zone Wetland, Nanwenghe National Reserve, Northeast China

Using pitfall traps, ground-dwelling beetle assemblages were investigated in Nanwenghe National Reserve, a typical Cold Temperate Zone wetland from Northeast China between 2009 and 2010. 9 sites comprised 3 habitat types, higher normal forest HNF, lower frozen forest LFF and lower frozen grass LFG were selected, and total of 1,289 individuals, consisting of 112 species were indentified. July and August had the peaks in diversity, richness and abundance. Rarefaction estimates of species richness indicated that traps in HNF had more species and individuals than LFF and LFG. According to the feeding habit, guilds was divided into four parts: Predators PR, Phytophagous PH, Scavengers SC, Fungivores FU, and PR>PH>SC>FU in quantity at both species and individual level, which suggested that the ground-dwelling beetles played an important role in substances cycle and energy flow of wetland ecosystem. Eretes sticticus, Cicindela hybrida, Pentodon mongolicus etc. displayed some particularities in different habitats, so the possibility that ground-dwelling beetles as indicator of quality of wetland or habitat environment was also discussed.

Gene pool conservation and tree improvement in Serbia

This paper presents the concepts applied in the gene pool conservation and tree improvement in Serbia. Gene pool conservation of tree species in Serbia includes a series of activities aiming at the sustainability and protection of genetic and species variability. This implies the investigation of genetic resources and their identification through the research of the genetic structure and the breeding system of individual species. Paper also includes the study of intra- and inter-population variability in experiments - provenance tests, progeny tests, half- and full-sib lines, etc. The increased use of the genetic potential in tree improvement in Serbia should be intensified by the following activities: improvement of production of normal forest seed, application of the concept of new selections directed primarily to the improvement of only one character, because in that case the result would be certain, establishment and management of seed orchards as specialized plantations for long-term production of genetically good-quality forest seeds, and the shortening of the improvement process by introducing new techniques and methods (molecular markers, somaclonal variation, genetic engineering, protoplast fusion, micropropagation, etc.).

Age structure and growth of understory white spruce under aspen

Juvenile white spruce (Piceaglauca (Moench) Voss) under an aspen (Populustremuloides Michx.) overstory were studied in nine boreal mixedwood stands in west-central Alberta. In each stand, 50 understory white spruce were cut for stem analysis at ground level, 30, 70, 130 cm, and every 100 cm to tree height. In four stands, recruitment of these understory spruce occurred immediately after the disturbance, while in others the recruitment was delayed several decades. The period of recruitment was as short as 15–20 years or continued for decades, producing an uneven-aged understory. Trees initiated on rotten logs had a slightly lower initial annual diameter increment but did not differ in height growth compared with those initiated on normal forest floor. The annual height increment increased as the trees grew in height, presumably as they overtopped successive layers of shading vegetation. When seedlings were less than 30 cm tall they grew less than 10 cm per year, but attained growth rates of 30 cm per year or more when they were taller than 230 cm. Height growth rates for these understory trees were comparable to reported growth rates of white spruce of similar size and age from clearcut areas.

The Application of Sustained Yield Management Objectives to Canada's Northern Forests

The author discusses a number of objections which have been made against the sustained yield concept in British Columbia. These have involved questions of equal annual harvest and market fluctuations; the normal forest and retention of old growth; rotation length; the marginal tree concept; the calculation of sustained yield allowable cuts and the question of management decision-making. A number of the objections do not relate directly to the sustained yield concept but to the particular methods of its implementation in British Columbia. It is pointed out that economic principles are just as subject to discretionary interpretation as are forestry principles. There appears to be an incomplete understanding of the sustained yield concept and the importance of its application at the management unit level — the point at which its objectives and applications become factual in nature. Economic principles alone do not provide an adequate alternative to the sustained yield concept, if the abuses of forest liquidation are to be avoided but they should be given due weight in the application of the concept. The author recommends that Canada's northern forests should be managed on a sustained yield basis.