The Changes in China's Forests: An Analysis Using the Forest Identity

Changes in forest carbon stocks are a determinant of the regional carbon budget. In the past several decades, China has experienced a pronounced increase in forest area and density. However, few comprehensive analyses have been conducted. In this study, we employed the Forest Identity concept to evaluate the changing status of China's forests over the past three decades, using national forest inventory data of five periods (1977–1981, 1984–1988, 1989–1993, 1994–1998, and 1999–2003). The results showed that forest area and growing stock density increased by 0.51% and 0.44% annually over the past three decades, while the conversion ratio of forest biomass to growing stock declined by 0.10% annually. These developments resulted in a net annual increase of 0.85% in forest carbon sequestration, which is equivalent to a net biomass carbon uptake of 43.8 Tg per year (1 Tg = 1012 g). This increase can be attributed to the national reforestation/afforestation programs, environmentally enhanced forest growth and economic development as indicated by the average gross domestic product

Biomass yield and modeling of logging residues of Terminalia superba in Southwestern Nigeria

An important aspect of sustainable forest management is periodical inventory, which coupled with the need for conservation of forest resources, formed the basis for the estimation of logging residues of Terminalia superba in the South-western part of Nigeria. A total of thirty one (31) trees were clear-felled in natural forests by plotless sampling techniques. Replicate wood discs and samples were taken fresh from the stem, branch and foliage residues left on the forest floors after the useful logs have been evacuated. The samples were dried to a constant weight in the laboratory and thereafter, the fresh/dry weight ratio of the samples was used to estimate the biomass of the residues of the felled trees. The mean biomass of the residues of Terminalia superba were 125.99kg, 135.42kg and 18.91kg for stem, branches and foliage respectively. Residues generated were found to be highest in the tree branches, followed by the stem and the foliage. The contribution of the various biomass components in relation to the total residue biomasses were 45.84% stem, 47.85% branch and 6.29% foliage. The use of Dbh as an independent variable in the prediction of models for estimating the biomass residues of the tree species was adjudged best because it performed well. The validation results showed that the selected models satisfied the assumptions of regression analysis. The practical implication of the models is that they could be readily used in the estimation of biomass residues of Terminalia superba.Keywords: Modelling, logging residue, biomass yield, Terminalia ivorensi

Application of Geographic Information System (GIS) in Construction: A Systematic Review

Purpose Notwithstanding the Geographical Information System (GIS) being a fast-emerging green area of a digital revolution, the available studies focus on different subject areas of application in the construction industry, with no study that clarifies its knowledge strands. Hence, this systematic review analyses GIS core area of application, its system integration patterns, challenges, and future directions in the construction industry. Design/methodology/approach A systematic review approach was employed, using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. A total of 60 articles published between 2011 and 2022 were identified, thoroughly reviewed, and analysed using thematic analysis. Findings The analysis revealed spatial planning and design, construction-task tracking, defect detection, and safety monitoring as its four main application-based areas. The findings showed that the adoption of GIS technology is rapidly expanding and being utilised more in building projects to visual-track construction activities. The review discovered an integrated pattern involving data flow from a device and window-form application to GIS, the pathways to data exchange between platforms-to-platforms, where ArcGIS is the most used software. Furthermore, the study highlighted the lack of interoperability between heterogeneous systems as the crux impediment to adopting GIS in the built environment. Originality/value The research provides a deep insight into possible areas where GIS is adopted in the construction industry, identifying areas of extensive and limited application coverage over one decade. Besides, it demystifies possible pathways for future integration opportunities of GIS with other emerging technologies within the construction industry