scholarly journals The sudden emergence of pathogenicity in insect–fungus symbioses threatens naive forest ecosystems

2011 ◽  
Vol 278 (1720) ◽  
pp. 2866-2873 ◽  
Author(s):  
Jiri Hulcr ◽  
Robert R. Dunn
Keyword(s):  
Tree Mortality ◽  
Forest Ecosystems ◽  
Current Understanding ◽  
Large Majority ◽  
Invasive Insect ◽  
Significant Damage ◽  
The World ◽  
Bark And Ambrosia Beetles ◽  
Diverse Community ◽  
Wood Boring

Invasive symbioses between wood-boring insects and fungi are emerging as a new and currently uncontrollable threat to forest ecosystems, as well as fruit and timber industries throughout the world. The bark and ambrosia beetles (Curculionidae: Scolytinae and Platypodinae) constitute the large majority of these pests, and are accompanied by a diverse community of fungal symbionts. Increasingly, some invasive symbioses are shifting from non-pathogenic saprotrophy in native ranges to a prolific tree-killing in invaded ranges, and are causing significant damage. In this paper, we review the current understanding of invasive insect–fungus symbioses. We then ask why some symbioses that evolved as non-pathogenic saprotrophs, turn into major tree-killers in non-native regions. We argue that a purely pathology-centred view of the guild is not sufficient for explaining the lethal encounters between exotic symbionts and naive trees. Instead, we propose several testable hypotheses that, if correct, lead to the conclusion that the sudden emergence of pathogenicity is a new evolutionary phenomenon with global biogeographical dynamics. To date, evidence suggests that virulence of the symbioses in invaded ranges is often triggered when several factors coincide: (i) invasion into territories with naive trees, (ii) the ability of the fungus to either overcome resistance of the naive host or trigger a suicidal over-reaction, and (iii) an ‘olfactory mismatch’ in the insect whereby a subset of live trees is perceived as dead and suitable for colonization. We suggest that individual cases of tree mortality caused by invasive insect–fungus symbionts should no longer be studied separately, but in a global, biogeographically and phylogenetically explicit comparative framework.

scholarly journals Anthropogenic Effects on Forest Ecosystems at Various Spatio-Temporal Scales

2002 ◽  
Vol 2 ◽  
pp. 827-841 ◽  
Author(s):  
Michael Bredemeier
Keyword(s):  
Air Pollution ◽  
Long Range ◽  
Acid Deposition ◽  
Soil Degradation ◽  
Forest Ecosystems ◽  
Global Scale ◽  
Soil Productivity ◽  
Long Term Effects ◽  
The World

The focus in this review of long-term effects on forest ecosystems is on human impact. As a classification of this differentiated and complex matter, three domains of long-term effects with different scales in space and time are distinguished: 1- Exploitation and conversion history of forests in areas of extended human settlement 2- Long-range air pollution and acid deposition in industrialized regions 3- Current global loss of forests and soil degradation.There is an evident link between the first and the third point in the list. Cultivation of primary forestland — with its tremendous effects on land cover — took place in Europe many centuries ago and continued for centuries. Deforestation today is a phenomenon predominantly observed in the developing countries, yet it threatens biotic and soil resources on a global scale. Acidification of forest soils caused by long-range air pollution from anthropogenic emission sources is a regional to continental problem in industrialized parts of the world. As a result of emission reduction legislation, atmospheric acid deposition is currently on the retreat in the richer industrialized regions (e.g., Europe, U.S., Japan); however, because many other regions of the world are at present rapidly developing their polluting industries (e.g., China and India), “acid rain” will most probably remain a serious ecological problem on regional scales. It is believed to have caused considerable destabilization of forest ecosystems, adding to the strong structural and biogeochemical impacts resulting from exploitation history.Deforestation and soil degradation cause the most pressing ecological problems for the time being, at least on the global scale. In many of those regions where loss of forests and soils is now high, it may be extremely difficult or impossible to restore forest ecosystems and soil productivity. Moreover, the driving forces, which are predominantly of a demographic and socioeconomic nature, do not yet seem to be lessening in strength. It can only be hoped that a wise policy of international cooperation and shared aims can cope with this problem in the future.

scholarly journals Chapter 8 Swelling and shrinking soils

2020 ◽  
Vol 29 (1) ◽  
pp. 223-242 ◽  
Author(s):  
Lee Jones ◽  
Vanessa Banks ◽  
Ian Jefferson
Keyword(s):  
Arid Environments ◽  
Local Site ◽  
Geotechnical Characterization ◽  
Significant Damage ◽  
The World ◽  
The Uk ◽  
The Cost ◽  
Structural Engineers ◽  
Semi Arid ◽  
Swelling And Shrinking

AbstractSwelling and shrinking soils are soils that can experience large changes in volume due to changes in water content. This may be due to seasonal changes in moisture content, local site changes such as leakage from water supply pipes or drains, changes to surface drainage and landscaping, or following the planting, removal or severe pruning of trees or hedges. These soils represent a significant hazard to structural engineers across the world due to their shrink–swell behaviour, with the cost of mitigation alone running into several billion pounds annually. These soils usually contain some form of clay mineral, such as smectite or vermiculite, and can be found in humid and arid/semi-arid environments where their expansive nature can cause significant damage to properties and infrastructure. This chapter discusses the properties and costs associated with shrink–swell soils, their formation and distribution throughout the UK and the rest of the world, and their geological and geotechnical characterization. It also considers the mechanisms of shrink-swell soils and their behaviour, reviewing strategies for managing them in an engineering context, before finally outlining the problem of trees and shrink–swell soils.

scholarly journals Stabilization of Black cotton soil using Fly ash

2021 ◽  
Vol 9 (5) ◽  
pp. 91-96
Author(s):  
Prerna Priya ◽  
Ran Vijay Singh
Keyword(s):  
Fly Ash ◽  
Soil Stabilization ◽  
Research Paper ◽  
Strength Properties ◽  
Engineering Properties ◽  
Black Cotton Soil ◽  
Significant Damage ◽  
The World ◽  
Wet Condition ◽  
Black Cotton Soils

Expansive Black cotton clay soils are widely distributed worldwide, and are a significant damage to infrastructure and buildigs.It is a common practice around the world to stabilize black cotton soil using fly ash to improve the strength of stabilized sub- base and sub grade soil. Soil stabilization is the improvement of strength or bearing capacity of soil by controlled compaction, proportioning or addition of suitable admixtures or stabilizers. The Black cotton soils are extremely hard when dry, but lose its strength fully when in wet condition. In monsoon they guzzle water and swell and in summer they shrink on evaporation of water from there. Because of its high Swelling and shrinkage characteristics the black cotton soils has been a challenge to the highway engineers.So in this research paper fly ash has been used to improve the various strength properties of natural black cotton soil.The objective of this research paper is to improve the engineering properties of black cotton soil by adding different percentage of fly ash by the weight of soil and make it suitable for construction. A series of standard Proctor tests (for calculation of MDD and OMC) and California Bearing Ratio (C.B.R) tests are conducted on both raw Black cotton soil and mixed soil with different percentages of fly ash (5%, 10%, 20%, 30%) by weight. A comparison between properties of raw black cotton soil, black cotton soil mixed with fly ash are performed .It is found that the properties of black cotton soil mixed with fly ash are suitably enhanced.

Teleology

2008 ◽  
Author(s):  
D.M. Walsh
Keyword(s):  
Early Modern ◽  
Adaptive Systems ◽  
Natural World ◽  
Current Understanding ◽  
Living Thing ◽  
The World ◽  
Modern Thinking ◽  
Self Organizing

Teleology is a mode of explanation in which the presence, occurrence, or nature of some phenomenon is explained by the end to which it contributes. The model of explanation is “pure mechanism” which holds that there is a single kind of stuff in the world-”matter” that exhibits a single kind of change, motion. It falls into three classes: the argument from nonactuality, the argument from intentionality, and the argument from normativity. These objections are because of early modern thinking about the natural world. These arguments rely on the Platonic model of transcendent teleology. Aristotelian teleology complements our current understanding of goal-directed, self-organizing, adaptive systems. The success of development can be explained by plasticity which is a goal-directed capacity of organisms to produce and maintain a stable, well-functioning living thing. The understanding of how evolution can be adaptive requires us to incorporate teleology.

scholarly journals Mitigating Effects of Climate Change and Deforestation on Bees With Respect to Their Ecology and Biology

2015 ◽  
Vol 6 (2) ◽  
pp. 1
Author(s):  
Musiliyu Oladipupo Mustafa ◽  
Olubusola Temitope Adeoye ◽  
Folorunso Ishaq Abdulalzeez ◽  
Olukayode Dare Akinyemi
Keyword(s):  
Climate Change ◽  
Forest Ecosystems ◽  
Royal Jelly ◽  
Global Climate ◽  
Tropical Rainforests ◽  
Contributing Factors ◽  
Honey Production ◽  
The World ◽  
Different Types ◽  
Populous Country

<p>Deforestation occurs around the world; though tropical rainforests are particularly targeted, it is considered to be one of the contributing factors to global climate change. While Nigeria is probably best known today for its oil deposits, according to the World Resources Institute, Nigeria is home to 4,715 different types of plant species, and over 550 species of breeding birds and mammals, making it one of the most ecologically vibrant places of the planet. It is also one of the most populous country with appalling deforestation record. This situation is hence making our ecosystems, biodiversity, agriculture and other natural endowments highly unsecured. The Forest provides excellent resources for bees and beekeeping, and bees are a vital part of forest ecosystems. Bees are essential for sustaining our environment because they</p><p>Pollinate flowering plants and conserves biological biodiversity along with their products (honey, propolis, bee wax, royal jelly and bee venom) which are beneficial to man. Conservation of the forest is therefore imperative for sustainable beekeeping. The study reviews the different causes of climate change and how they affect different natural forest activities which are weather-dependent. Also how climate change and other causes (both natural and man-made) lead to deforestation, which in turn distort sustainable honey production in Nigeria. Different sustainable measures hoped to alleviate the effects of climate change and deforestation where also discussed. </p>

Pressing problems of the euro zone — And beyond (OR: What may break the camel’s back)

2012 ◽  
Vol 62 (4) ◽  
pp. 423-434
Author(s):  
Jan Winiecki
Keyword(s):  
Monetary Union ◽  
Present Writer ◽  
Large Majority ◽  
Short Term ◽  
Large Measure ◽  
Euro Zone ◽  
The Past ◽  
The World ◽  
Simple Question

A look at the Western debate about West’s problems reveals what the present writer regards in a large measure as an irritating superficiality. Nowhere is it better visible than in the mainstream discussions about the euro zone and its problems, where most debaters glide over the fundamentals of Europe’s long-term problems and concentrate on the superficial and short-term issues. The discussions on how to “save” the euro zone strangely forget the defects in its creation, glide over the lessons to be drawn from policies pursued during the past decade, and defend the virtue of maintaining its present membership. But the problems of Europe run much deeper than the survival or collapse of the monetary union. Even if we assume that the problems of confidence the member states have in each other’s behaviour are restored and the rest of the world regains confidence in the institutions of the monetary union, the fundamental problems will remain unsolved. A clue to the real long-term problems may be found in the answer to a rather simple question. It runs as follows: “Why is the large majority of European countries indebted to such an extent that any further increase in debt to GDP ratio generates panic reactions among potential lenders?”

On the 11.755 insect taxa named by Charles P. Alexander

Zoosymposia ◽  
2009 ◽  
Vol 3 (1) ◽  
pp. 9-15
Author(s):  
PJOTR OOSTERBROEK
Keyword(s):  
Large Majority ◽  
Short Biography ◽  
The World ◽  
Biogeographical Regions

Charles P. Alexander is the author of 11.755 insect taxa, the large majority of which are in the four families of craneflies (Diptera, Tipuloidea). After a short biography, an overview is presented of the number of taxa in relation to biogeographical regions, families, synonyms, etc. in craneflies (11.556 names) as well as in nine other families of Diptera (198 names) and one in Plecoptera. For craneflies, the Alexander taxa cover about 70% of all species names and some 46% of the genera and subgenera of the world.

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