scholarly journals GROWTH PERFORMANCE AND MANAGEMENT IN MIXED FOREST STANDS

2018 ◽  
Author(s):  
Heinz RÖHLE
Keyword(s):  
Climate Change ◽  
Mixed Forest ◽  
Biomass Productivity ◽  
Simulation Models ◽  
Forest Area ◽  
Population Projections ◽  
Forest Sector ◽  
Forest Conversion ◽  
World Population ◽  
Mixed Stands

In 2017, the global population stands at about 7.6 billion. Due to the medium variant of the population projections, developed by the UN, the world population will grow to nearly 10 billion by the middle of this century. As a consequence, the worldwide demand for wood will increase. Therefore, the forest sector has to develop concepts in order to cope with the increasing demand for wood, the altering environmental conditions and the challenge of climate change. Modified silvicultural treatment programs may contribute to solving these questions. Appropriate measures are the conversion of pure stands into mixed stands, the promotion of natural regeneration instead of artificial regeneration and the creation of structured forests consisting of indigenous or foreign tree species, which are better adapted to climate change and/or are growing faster. Mixed stands often exceed the volume as well as the biomass productivity of pure stands and increase the biodiversity of forest landscapes. Forest simulation models are a prerequisite for the management of mixed stands. They provide enhanced opportunities of planning for forest conversion and facilitate the decision support in forest practice. These model approaches support the development of goal oriented thinning programs and make it possible to test and optimize alternative silvicultural concepts without the establishment of experimental plots. The Bavarian State Forest Enterprise (Bayerische Staatsforsten) is managing 808731 ha of forest area in the southern part of Germany. Since 2005 this enterprise is converting pure, coniferous stands (> 200000 ha of forest area) into mixed, uneven-aged forests. A simulation program (single tree simulator) is used in order to achieve this goal.

scholarly journals Root crops agroforestry for greening the sustainability of green revolution

2018 ◽  
Vol 8 (1) ◽  
pp. 26-37
Author(s):  
Y Widodo ◽  
S Wahyuningsih ◽  
JS Utomo ◽  
A Subagio
Keyword(s):  
Climate Change ◽  
Forest Canopy ◽  
Fossil Fuel ◽  
Agricultural Land ◽  
Green Revolution ◽  
Forest Conversion ◽  
World Population ◽  
Root Crops ◽  
Wide Range ◽  
Agro Forestry

Green revolution started at mid of twentieth century was the answer of anxiousness reminded by Malthusian that food scarcity problems in relation with population growth. In concurrence with exploitation of fossil fuel for agriculture mechanization as well as agrochemicals in the form of inorganic fertilizer and pesticide, green revolution by introducing high yielding varieties of cereals and grains was able to nourish the world population by increasing productivity. Indeed, from beginning of mechanization with fossil fuel based as advised by Rudolf Diesel then Arrhenius would be affected to the release of CO2 to the atmosphere and consequently exaggerating climate change as suffered by current and future generations. Under green revolution based on cereals and grains affected forest conversion into open agricultural land, because both commodities are sun-loving crops, which are hate to the shade. On the other hand, to slow the severity of climate change natural forest must be conserved tightly. Entering third millennium demand of food production with ecologically friendly is stronger. Hence, green revolution needs to be amended into greener perspectives. Thus, implementation of agro-forestry into wide range of agro-ecological zone is urgently innovated. Fortunately, shade tolerant of root crops has significant advantage to be developed under agro-forestry. Under shade of forest canopy at basal forest strata, root crops are able to sequester CO2 to be converted into carbohydrate and other compounds to provide food for the dweller. Back to nature is not only a slogan, with root crops under agro-forestry is a reality; fresh root up to 30 t ha-1 can be harvested yearly as the source of food and renewable fuel as well. This potential is very worthy to improve and greening the existing green revolution to be more sustainable.Int. J. Agril. Res. Innov. & Tech. 8 (1): 26-37, June, 2018

scholarly journals COVID-19 and future pandemics: a global systems approach and relevance to SDGs

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Tharanga Thoradeniya ◽  
Saroj Jayasinghe
Keyword(s):  
Climate Change ◽  
Global Governance ◽  
Systems Approach ◽  
Rna Virus ◽  
Modern Human ◽  
Systems Science ◽  
World Population ◽  
Ecological Processes ◽  
Physical Environments ◽  
Corporate Interests

Abstract Background The COVID-19 pandemic is adversely impacting modern human civilization. A global view using a systems science approach is necessary to recognize the close interactions between health of animals, humans and the environment. Discussion A model is developed initially by describing five sequential or parallel steps on how a RNA virus emerged from animals and became a pandemic: 1. Origins in the animal kingdom; 2. Transmission to domesticated animals; 3. Inter-species transmission to humans; 4. Local epidemics; 5. Global spread towards a pandemic. The next stage identifies global level determinants from the physical environments, the biosphere and social environment that influence these steps to derive a generic conceptual model. It identifies that future pandemics are likely to emerge from ecological processes (climate change, loss of biodiversity), anthropogenic social processes (i.e. corporate interests, culture and globalization) and world population growth. Intervention would therefore require modifications or dampening these generators and prevent future periodic pandemics that would reverse human development. Addressing issues such as poorly planned urbanization, climate change and deforestation coincide with SDGs such as sustainable cities and communities (Goal 11), climate action (Goal 13) and preserving forests and other ecosystems (Goal 15). This will be an added justification to address them as global priorities. Some determinants in the model are poorly addressed by SDGs such as the case of population pressures, cultural factors, corporate interests and globalization. The overarching process of globalization will require modifications to the structures, processes and mechanisms of global governance. The defects in global governance are arguably due to historical reasons and the neo-liberal capitalist order. This became evident especially in the aftermath of the COVID-19 when the vaccination roll-out led to violations of universal values of equity and right to life by some of the powerful and affluent nations. Summary A systems approach leads us to a model that shows the need to tackle several factors, some of which are not adequately addressed by SDGs and require restructuring of global governance and political economy.

scholarly journals Distribution of the timber quality attribute ‘knot surface’ in logs of Fagus sylvatica L. from pure and mixed forest stands

2021 ◽  
Author(s):  
Kirsten Höwler ◽  
Torsten Vor ◽  
Peter Schall ◽  
Peter Annighöfer ◽  
Dominik Seidel ◽  
...  
Keyword(s):  
Fagus Sylvatica ◽  
Mixed Forest ◽  
European Beech ◽  
Forest Stands ◽  
Species Identity ◽  
Mixed Stands ◽  
Mixed Forests ◽  
Climate Conditions ◽  
Timber Quality ◽  
Positive Effects

AbstractResearch on mixed forests has mostly focused on tree growth and productivity, or resistance and resilience in changing climate conditions, but only rarely on the effects of tree species mixing on timber quality. In particular, it is still unclear whether the numerous positive effects of mixed forests on productivity and stability come at the expense of timber quality. In this study, we used photographs of sawn boards from 90 European beech (Fagus sylvatica L.) trees of mixed and pure forest stands to analyze internal timber quality through the quality indicator knot surface that was quantitatively assessed using the software Datinf® Measure. We observed a decrease in knot surface with increasing distance from the pith as well as smaller values in the lower log sections. Regarding the influence of neighborhood species identity, we found only minor effects meaning that timber qualities in mixed stands of beech and Norway spruce (Picea abies (L.) H. Karst.) tended to be slightly worse compared to pure beech stands.

scholarly journals Object Oriented Classification for Mapping Mixed and Pure Forest Stands Using Very-High Resolution Imagery

2021 ◽  
Vol 13 (13) ◽  
pp. 2508
Author(s):  
Loredana Oreti ◽  
Diego Giuliarelli ◽  
Antonio Tomao ◽  
Anna Barbati
Keyword(s):  
High Resolution ◽  
Spatial Scales ◽  
Parametric Method ◽  
Mixed Forest ◽  
Mixed Stands ◽  
Mapping Unit ◽  
Mixed Forests ◽  
High Resolution Imagery ◽  
Very High Resolution Imagery ◽  
Very High

The importance of mixed forests is increasingly recognized on a scientific level, due to their greater productivity and efficiency in resource use, compared to pure stands. However, a reliable quantification of the actual spatial extent of mixed stands on a fine spatial scale is still lacking. Indeed, classification and mapping of mixed populations, especially with semi-automatic procedures, has been a challenging issue up to date. The main objective of this study is to evaluate the potential of Object-Based Image Analysis (OBIA) and Very-High-Resolution imagery (VHR) to detect and map mixed forests of broadleaves and coniferous trees with a Minimum Mapping Unit (MMU) of 500 m2. This study evaluates segmentation-based classification paired with non-parametric method K- nearest-neighbors (K-NN), trained with a dataset independent from the validation one. The forest area mapped as mixed forest canopies in the study area amounts to 11%, with an overall accuracy being equal to 85% and K of 0.78. Better levels of user and producer accuracies (85–93%) are reached in conifer and broadleaved dominated stands. The study findings demonstrate that the very high resolution images (0.20 m of spatial resolutions) can be reliably used to detect the fine-grained pattern of rare mixed forests, thus supporting the monitoring and management of forest resources also on fine spatial scales.

scholarly journals Use of forest land for national-priority infrastructures in Nepal

2017 ◽  
Vol 27 (1) ◽  
pp. 60-64
Author(s):  
U. R. Sharma
Keyword(s):  
Forest Area ◽  
Forest Conversion ◽  
Infrastructure Development ◽  
Infrastructure Projects ◽  
Forest Land ◽  
National Priority ◽  
Equivalent Area ◽  
Strict Enforcement ◽  
The Government ◽  
Forest Lands

 Forest conversion has been identified as one of the several bottlenecks affecting upon the major infrastructure projects in Nepal, especially in the energy and transport sectors. Nepal’s policy requires at least 40% of its land cover under forest. This means if any forest land is converted to non-forest land, it must be compensated with an equivalent area, preferably in the similar ecotype in the nation. In addition, a specified number of trees must be planted for the number of trees felled in the project site, and the site must be managed and protected for five years by the developers. These provisions have led to growing resentment between the developers and the Ministry of Forests and Soil Conservation (MFSC), leading to delay in providing forest lands for infrastructure projects. With a view to develop mechanisms for the government to rapidly provide forest land for nationally important infrastructure projects, the Government databases were examined to analyze the forests handed over to the developers for non-forestry uses. The data showed that a total of 14,028.4 ha of forest area were handed over to the developers for non-forestry uses until the end of 2015. On an average, 263.8 ha forest area was found to be handed over to the developers between the period of 2010–2013. However, there is a declining trend of forest handed over for non-forestry purposes in the recent years. The decline could be due to the strict enforcement of the legal provision which limits the conversion of forest areas to non-forest areas except in the case of the “national priority projects”. It has been recommended that the conversion of forest for infrastructure development should be examined with a holistic perspective by taking all the related components of forest conversion into consideration, from providing forest land for replacement planting. It is recommended that the Forest Product Development Board (FPDB), a parastatal organization under the MFSC, should be entrusted with the work of plantation related to forest conversion. The fund for this work should flow directly from the developers to the FPDB. The possibility of forming a land bank to facilitate the work of the FPDB is also recommended.Banko Janakari, Vol. 27, No. 1, Page: 60-64

Tending this Fragile Earth, Our Island Home: The Pope's Encyclical in Dialogue with Ecomimesis, a Design Model for Conservation Stewardship

2018 ◽  
Vol 100 (4) ◽  
pp. 745-766
Author(s):  
Lillian C. Woo
Keyword(s):  
Climate Change ◽  
Water Pollution ◽  
Anthropogenic Impact ◽  
Natural World ◽  
Design Solution ◽  
World Population ◽  
Natural Ecosystem ◽  
Natural Ecosystems ◽  
The Earth ◽  
The World

In the last fifty years, empirical evidence has shown that climate change and environmental degradation are largely the results of increased world population, economic development, and changes in cultural and social norms. Thus far we have been unable to slow or reverse the practices that continue to produce more air and water pollution, soil and ocean degradation, and ecosystem decline. This paper analyzes the negative anthropogenic impact on the ecosystem and proposes a new design solution: ecomimesis, which uses the natural ecosystem as its template to conserve, restore, and improve existing ecosystems. Through its nonintrusive strategies and designs, and its goal of preserving natural ecosystems and the earth, ecomimesis can become an integral part of stabilizing and rehabilitating our natural world at the same time that it addresses the needs of growing economies and populations around the world.

scholarly journals A vital link: water and vegetation in the Anthropocene

2013 ◽  
Vol 17 (10) ◽  
pp. 3841-3852 ◽  
Author(s):  
D. Gerten
Keyword(s):  
Climate Change ◽  
Vegetation Dynamics ◽  
Food Production ◽  
Ecosystem Dynamics ◽  
Active Management ◽  
World Population ◽  
Water Limitation ◽  
Research Perspectives ◽  
Co2 Effects ◽  
Water Vegetation

Abstract. This paper argues that the interplay of water, carbon and vegetation dynamics fundamentally links some global trends in the current and conceivable future Anthropocene, such as cropland expansion, freshwater use, and climate change and its impacts. Based on a review of recent literature including geographically explicit simulation studies with the process-based LPJmL global biosphere model, it demonstrates that the connectivity of water and vegetation dynamics is vital for water security, food security and (terrestrial) ecosystem dynamics alike. The water limitation of net primary production of both natural and agricultural plants – already pronounced in many regions – is shown to increase in many places under projected climate change, though this development is partially offset by water-saving direct CO2 effects. Natural vegetation can to some degree adapt dynamically to higher water limitation, but agricultural crops usually require some form of active management to overcome it – among them irrigation, soil conservation and eventually shifts of cropland to areas that are less water-limited due to more favourable climatic conditions. While crucial to secure food production for a growing world population, such human interventions in water–vegetation systems have, as also shown, repercussions on the water cycle. Indeed, land use changes are shown to be the second-most important influence on the terrestrial water balance in recent times. Furthermore, climate change (warming and precipitation changes) will in many regions increase irrigation demand and decrease water availability, impeding rainfed and irrigated food production (if not CO2 effects counterbalance this impact – which is unlikely at least in poorly managed systems). Drawing from these exemplary investigations, some research perspectives on how to further improve our knowledge of human–water–vegetation interactions in the Anthropocene are outlined.

scholarly journals Peculiarly pleasant weather for US maize

2018 ◽  
Vol 115 (47) ◽  
pp. 11935-11940 ◽  
Author(s):  
Ethan E. Butler ◽  
Nathaniel D. Mueller ◽  
Peter Huybers
Keyword(s):  
Climate Change ◽  
Growing Season ◽  
Crop Model ◽  
World Population ◽  
Growth Phases ◽  
Climate Trends ◽  
Historical Trends ◽  
Yield Trends ◽  
The Relationship ◽  
Temperature Responses

Continuation of historical trends in crop yield are critical to meeting the demands of a growing and more affluent world population. Climate change may compromise our ability to meet these demands, but estimates vary widely, highlighting the importance of understanding historical interactions between yield and climate trends. The relationship between temperature and yield is nuanced, involving differential yield outcomes to warm (9−29 °C) and hot (>29 °C) temperatures and differing sensitivity across growth phases. Here, we use a crop model that resolves temperature responses according to magnitude and growth phase to show that US maize has benefited from weather shifts since 1981. Improvements are related to lengthening of the growing season and cooling of the hottest temperatures. Furthermore, current farmer cropping schedules are more beneficial in the climate of the last decade than they would have been in earlier decades, indicating statistically significant adaptation to a changing climate of 13 kg·ha−1· decade−1. All together, the better weather experienced by US maize accounts for 28% of the yield trends since 1981. Sustaining positive trends in yield depends on whether improvements in agricultural climate continue and the degree to which farmers adapt to future climates.

Competition theory — science and application in mixed forest stands: review of experimental and modelling methods and suggestions for future research

2013 ◽  
Vol 21 (2) ◽  
pp. 71-84 ◽  
Author(s):  
Guy R. Larocque ◽  
Nancy Luckai ◽  
Shailendra N. Adhikary ◽  
Arthur Groot ◽  
F. Wayne Bell ◽  
...  
Keyword(s):  
Mixed Forest ◽  
Single Species ◽  
Experimental Designs ◽  
Competitive Interactions ◽  
Future Research ◽  
Relative Importance ◽  
Forest Stands ◽  
Management Scenarios ◽  
Mixed Stands ◽  
Individual Tree

Competition in forest stands has long been of interest to researchers. However, much of the knowledge originates from empirical studies that examined the effects of competition. For instance, many studies were focused on the effects of the presence of herbaceous species on the development of tree seedlings or the decrease in individual tree growth with increases in stand density. Several models that incorporate competitive effects have been developed to predict tree and stand growth, but with simplified representations of competitive interactions. While these studies provided guidance useful for forest management, they contributed only partially to furthering our understanding of competitive mechanisms. Also, most competition studies were conducted in single-species stands. As competitive interactions occurring in mixed stands are characterized by a higher degree of complexity than those in single-species stands, a better understanding of these mechanisms can contribute to developing optimal management scenarios. The dynamics of forest stands with at least two species may be affected not only by competition, but also by facilitation or complementarity mechanisms. Thus, knowledge of the mechanisms may provide insight into the relative importance of intra- versus inter-specific competition and whether competition is symmetric or asymmetric. Special attention to the implementation of field experimental designs is warranted for mixed stands. While traditional spacing trials are appropriate for single-species stands, the examination of competitive interactions in mixed stands requires more complex experimental designs to examine the relative importance of species combinations. Forest productivity models allow resource managers to test different management scenarios, but again most of these models were developed for single-species stands. As competitive interactions are more complex in mixed stands, models developed to predict their dynamics will need to include more mechanistic representations of competition.

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