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Wood and Wood Modification
Published in Dick Sandberg, Andreja Kutnar, Olov Karlsson, Dennis Jones, Wood Modification Technologies, 2021
Dick Sandberg, Andreja Kutnar, Olov Karlsson, Dennis Jones
Termites are highly effective at processing biomass and are estimated to process up to 35% of dead wood in the tropics (Derma et al., 2009), and another study of tropical and subtropical areas has suggested that termites account for 10% of animal biomass and 95% of soil insect biomass (Donovan et al., 2007). Their activities create favourable conditions for primary producers, including maintaining soil pH, increasing water retention, mediating decomposition and nutrient cycling, and creating surface areas suitable for microbial colonisation. However, the desire to source suitable feedstocks has led to problems where timber has been used in construction and our built environment. Some species of termites feed on plant material and timber used by humans, necessitating expensive repairs, prevention and control efforts. Termites may also damage materials adjoining or close to timber that is being attacked for food, and this can create problems with items such as electrical and telephone wiring, cables, dams and farming equipment. One study (Jones et al., 2015) has suggested that a colony of 200,000 termites can consume up to 5.9 kg of cellulose per year. It is estimated that worldwide the costs for termite control and repair are round $30 billion (Rust and Su, 2012), most of these costs (80%) being associated with subterranean termites.
Timber and timber products
Published in Arthur Lyons, Materials for Architects and Builders, 2019
Termites are social insects, similar in size to ants (4–5 mm), that live in colonies containing millions of individuals. Most species of termites are beneficial to nature in breaking down organic matter, but a few varieties can cause catastrophic damage to buildings. There are two main types of termites. The ‘drywood’ types live in the wood that they attack, whereas the ‘subterranean’ varieties live in nests that may be at a distance from the timber under attack. The subterranean termite family Rhinotermitidae is the major cause of building damage, with the genus Reticulitermes being a significant threat in the UK. Occasionally, imported timber may bring in infestations; however, these can be controlled with hexaflumuron, an insect growth regulator, within bait. The primary source of food for termites is the cellulose in wood, particularly from structural softwood timbers near to ground level or in partially decayed timber. Timber may be only slightly affected or it may be heavily excavated, leaving only the surface and any protective coatings. In areas at risk of termites, termiticide protection may be appropriate, but where attack has already occurred specialist advice from the Forestry Commission is essential. Colony elimination by physical, chemical or biological techniques can be a slow process, taking months or even years to complete.
Building pathology, maintenance and refurbishment
Published in Mike Riley, Alison Cotgrave, Michael Farragher, Building Design, Construction and Performance in Tropical Climates, 2017
Zahiruddin Fitri Abu Hassan, Azlan Shah Ali, Shirley Jin Lin Chua, Mohd Rizal Baharum
Termites are uncommon in temperate zones; although they do exist in Europe and North America they are much less prevalent than in tropical areas. There are numerous species in existence with more than a thousand species found in Africa alone. It is estimated that over one million active termite mounds are in existence in the Kruger National Park alone (Meyer 1999). In Asia and Australasia they are endemic and give rise to considerable damage to buildings through infestation if suitable measures are not effected to counter them. Termites fall into three broad categories or ecological groups. First, dampwood termites which are found only in coniferous forests; second, drywood termites which inhabit hardwood forests; and finally subterranean termites. Depending upon the locality and the species which are prevalent in a particular region termites can be the source of considerable, even devastating damage to timber elements of buildings and other structures. In many instances the presence of the infestation may go undetected until damage to the timber is quite advanced. The nature of the action of the termite is such that the timber is consumed from the inside, leaving the insects largely concealed with a thin layer of material remaining on the external faces, leaving a void internally. Termites thrive in warm, tropical climates and as such are the source of concern in many traditional timber buildings. The traditional steps to avoid such damage include the use of eucalyptus, which is disliked by the termite, and the impregnation of timber with used fuel oil and other available preservatives.
Ex situ studies on Macrotermes bellicosus as a potential bioremediation tool of polluted dump soil sites for Sub Saharan Africa
Published in Soil and Sediment Contamination: An International Journal, 2022
Daniel Ingo Hefft, Osikemekha Anthony Anani, Felix Aigbodion, Charity Osadagbonyi, Charles Oluwaseun Adetunji, Afure Ejomah, Uyi Osariyekemwen, Alex Enuneku
The African mound workers (Macrotemes bellicosus) have been considered recently to be an effective converter of materials. Therefore, this portends them as a sustainable tool for effective entomoremediation of the heavily contaminated environment, by improving the soil quality and structure, and cycling of nutrients. Since African mound workers can be easily found throughout Nigeria, as well as entemoremediation offering a low-cost approach to address environmental pollution, it has huge and unlocked potential to be applied throughout Nigeria and its Sub-Saharan neighbors. In addition, African mound workers (Macrotermes bellicosus) aid in the effective aeration of the soil for soil macro and micro fauna as well as enabling adequate survival of essential insects in the affected environment. This could also increase the level of their gaseous exchanges and lead overall to healthier environments (Ejomah et al. 2020; Jouquet et al. 2019, 2011). Termites, being a decomposer, have a special role in providing ecosystem services, thus influencing dead plants via decomposing them into organic matter for plant utilization (Freymann et al. 2008; Jouquet et al. 2019).