Mangroves As Coastal Bio-Shield: A Review of Mangroves Performance in Wave Attenuation

Mangroves have been recognized as soft structures that provide coastline protection. The capability of dampening waves helps minimize destruction from catastrophic events including erosive wave attacks, torrential storms, and tsunamis. Mangroves act as the first line of coastal defense in natural tragedies such as during the Super Typhoon Haiyan 2013 and Indian Ocean Tsunami 2004, whereby the leeward mangrove area encountered less damage than the unprotected area. This has further brought the attention of researchers to study the attenuation performance of these coastal vegetations. Based on an extensive literature review, this paper discusses the attenuation mechanism of mangroves, the factors influencing the dissipation performance, studies on mangrove dissipation via different approaches, the dissipation efficiency, mangrove conservation and rehabilitation efforts in Malaysia and implementation of mangrove as coastal bio-shield in other countries. The study highlights that mangrove parameters (such as species, width, density etc.) and wave parameters (such as wave period and incident wave height) are among the contributing factors in mangroves-induced wave attenuation, with different efficiency rates performed by different mangroves and waves parameters. Towards that end, several improvements are proposed for future research such as to incorporate all influencing dissipation factors with specific analysis for each species of mangroves, to perform validation on the studied mangroves attenuation capacity in different settings and circumstances, as well as to address the extent of protection by the rehabilitated mangroves. A systematic and effective management strategy incorporating ecological, forestry, and coastal engineering knowledge should be considered to ensure a sustainable mangroves ecosystem and promising coastline protection by mangroves. Doi: 10.28991/cej-2021-03091772 Full Text: PDF

Natural disturbance regimes for implementation of ecological forestry: a review and case study from Nova Scotia, Canada

Ecological forestry is based on the idea that forest patterns and processes are more likely to persist if harvest strategies produce stand structures, return intervals, and severities similar to those from natural disturbances. Taylor et al. (2020) reviewed forest natural disturbance regimes in Nova Scotia, Canada, to support implementation of ecological forestry. In this follow-up paper, we 1) review use of natural disturbance regimes to determine target harvest rotations, age structures, and residual stand structures; and 2) describe a novel approach for use of natural disturbance regimes in ecological forestry developed for Nova Scotia. Most examples of ecological forestry consider only the local, dominant disturbance agent, such as fire in boreal regions. Our approach included: 1) using current ecological land classification to map potential natural vegetation (PNV) community types; 2) determining cumulative natural disturbance effects of all major disturbances, in our case fire, hurricanes, windstorm, and insect outbreaks for each PNV; and 3) using natural disturbance regime parameters to derive guidelines for ecological forestry for each PNV. We analyzed disturbance occurrence and return intervals based on low, moderate, and high severity classes (<30, 30-60, and >60% of biomass of living trees killed), which were used to determine mean annual disturbance rates by severity class. Return intervals were used to infer target stand age-class distributions for high, moderate, and low severity disturbances for each PNV. The range of variation in rates of high severity disturbances among PNVs was from 0.28% yr-1 in Tolerant Hardwood to 2.1% yr-1 in the Highland Fir PNV, equating to return intervals of 357 years in Tolerant Hardwood to 48 yrs in Highland Fir PNVs. As an example, this return interval for the Tolerant Hardwood PNV resulted in target rotation lengths of 200 years for 35% of the PNV area, 500 years for 40%, and 1000 years for 25%. The proposed approach of determining natural disturbance regimes for PNV communities and calculating target disturbance rates and corresponding harvest rotation lengths or entry times appears to be a feasible method to guide ecological forestry in any region with a strong ecological land classification system and multiple disturbance agents.

In Pursuit of Ecological Forestry: Historical Barriers and Ecosystem Implications

The global need for ecological forestry is more important today than ever. But despite a century of technical advancements from forestry leaders—especially in North America and Europe—the world's forest ecosystem is declining at a time when carbon levels are rising, and biodiversity is at risk. Unfortunately, even the world's innovation leaders are struggling to change industry practices in their home countries. Undeterred by the lack of progress, new efforts are being attempted with Europe taking a markedly different path than the U.S. In the U.S., the pursuit of ecological forestry has embraced natural disturbance frameworks and stresses customized goals for local environments and social demands. In Europe, a broad application of low-intensity harvest protocols and canopy protection is being promoted for many forest types. The U.S. approach shows strong ecological promise at local and regional scales, but its broad adoption within the industry as a whole is limited and inconsistent. For the European approach, the broadly elevated priority of continuous canopy draws scientific critics, but their forestry industry is adopting and applying the concept. Although lower-intensity harvests are common to both regions, evidence suggests that Europe may be using low-intensity methods too broadly, while the U.S. is using them too little. The objective of this perspective is to describe the historical development of ecological forestry in Europe and the United States, and to propose research adjustments to help America pursue broader ecological forestry application. By understanding the historical precedents that influence forestry perceptions and the differences in contemporary approaches among forestry leaders, forestry scientists may be better equipped to design research and promote practices that can influence industry behavior for better ecosystem implications.

A review of natural disturbances to inform implementation of ecological forestry in Nova Scotia, Canada

Like many jurisdictions across North America, the province of Nova Scotia (NS) is faced with the challenge of restoring its forests to a more natural, presettlement state through implementation of ecological forestry. At the core of ecological forestry is the idea that natural forest structures and processes may be approximated by designing management practices that emulate natural disturbances. Successful natural disturbance emulation depends on fundamental knowledge of disturbance characteristics, including identification of specific disturbance agents, their spatial extent, severity, and return interval. To date, no comprehensive synthesis of existing data has been undertaken to document the natural disturbance regime of NS forests, limiting the application of natural disturbance emulation. Using over 300 years of documents and available data, we identified the main natural disturbance agents that affect NS forests and characterized their regimes. Overall, fire, wind (predominantly hurricanes), and outbreaks of spruce budworm (Choristoneura fumiferana (Clemens)) are the most important disturbance agents, causing substantial areas of low- (<30% mortality), moderate- (30%–60%), and high- (>60%) severity disturbance. While characterization of natural historic fire is challenging, due to past human ignitions and suppression, we estimated that the mean annual disturbance rate of moderate- to high-severity fire ranged between 0.17% and 0.4%·year−1 (return interval of 250–600 years), depending on ecosystem type. Hurricanes make landfall in NS, on average, every 7 years, resulting in wide-scale (>500 ha) forest damage. While hurricane track and damage severity vary widely among storms, the return interval of low- to high-severity damage is 700–1250 years (0.14%–0.08%·year−1). Conversely, the return interval of host-specific spruce budworm outbreaks is much shorter (<50 years) but more periodic, causing wide-scale, low- to high-severity damage to spruce–fir forests every 30–40 years. Further disturbance agents such as other insects (e.g., spruce beetle), diseases, ice storms, drought, and mammals can be locally important and (or) detrimental to individual tree species but contribute little to overall disturbance in NS. Climate change is expected to significantly alter the disturbance regime of NS, affecting current disturbances (e.g., increased fire) and driving the introduction of novel agents (e.g., hemlock wooly adelgid), and continued monitoring is needed to understand these changes.

Extension of Forestry Technology in Ecological Forestry Con- struction and Its Countermeasures

Promoting the continuous and smooth development of ecological environment and forestry projects can effectively adjust the forest area climate, constantly purify the air in the forest area, and effectively avoid the serious desertification within the forest area land, so as to effectively improve the local ecological environment. At the present stage, due to the low promotion and application of technologies related to ecological forestry project construction in most parts of China and the lack of comprehensive and in-depth understanding, a lot of technical problems have emerged in the process of promoting the construction and development of ecological and environmental forestry projects. Based on this, this paper analyzes and explores the problems existing in the forestry technology promotion in the ecological forestry construction.

Economic aspects of forest education for general public in Poland. A case study of promotional forest complexes

Forest plays an important role in humane life.Nowadays, a significant development of tourism and education can be observed in the forests. For many visitors forests are the destination of tourist trips. However, in order to develop tourism successfully there, the forest areas have to be properly developed. Recreation and relax in forest can become an additional source of income for forest districts and their administrative entities. This activity constitutes an important source of income for the local economy through the costs incurred by visitors for the journey to the forest for educational and recreational purposes. Within the framework of this institution there are. In Poland, in 2016, there were 25 Promotional Forest Complexes (PFCs), whose task is to realize the social functions of forests. FPCs are an original Polish idea for promoting ecological forestry. Foresters within PFCs conduct various activities, including promoting sustainable forest economy, supporting scientific research and providing forest education for general public. The educational activity of PFCs is financed by two sources of funding internal (own) financing and external financing (foreign). The main source of financing education in PFCs is the own resources of the forest districts. The aim of the article is to show the forms of forest education in Poland, as well as its economic aspects. It also presents the expenditures and benefits drawn from the development of the educational function of forests. The author attempts to evaluate the prospective cost of visitors’ attendance in these areas. In order to write the article, the authors used the following research methods: empirical analysis of secondary materials, literature analysis and statistical analysis.