Termites In Forests Research Articles

A Lab-Based Study of Temperate Forest Termite Impacts on Two Common Wood-Rot Fungi.

Termites and fungi are the primary decomposers of dead wood. Interactions between wood-feeding termites and wood-rot fungi are inevitable given their shared food source. Termites have developed multiple defense strategies against infectious fungi, such as Metarhizium spp., that include antifungal proteins in their saliva and fungal inhibition properties in their gut. The antifungal properties of termite salivary secretions depend on β-1,3-glucanases that are likely to be effective against a broad spectrum of filamentous fungi. Given the overlap in niches, there is opportunity for interference competition between termites and wood-rot fungi to occur. Here we demonstrate that β-1,3-glucanases in the saliva and the antifungal properties of the gut of the eastern subterranean termite Reticulitermes flavipes (Kollar) (Blattodea: Rhinotermitidae) affects the growth of two common wood-rot fungi, Gloeophyllum trabeum Persoon (Murrill) (Gloeophyllales: Gloeophyllaceae) and Phanerochaete chrysosporium (Burdsall) (Polyporales: Phanerochaetaceae).

Inoculation of ophiostomatoid fungi in loblolly pine trees increases the presence of subterranean termites in fungal lesions

Many bluestain (ophiostomatoid) fungi are inoculated into trees via bark beetle activity, but their ecological roles are not fully understood, particularly for interactions with invertebrates outside bark beetle and phoretic mite associations. Recently, correlational field studies and small-scale laboratory feeding trials have demonstrated subterranean termites have increased presence on and preferential feeding of bluestain-infected wood, but experimental field evidence is lacking. To test the hypothesis that bluestain fungi increase termite presence in infected trees, we inoculated 72 loblolly pine trees in the southeastern USA with one of four bluestain fungi (Ophiostoma minus, O. ips, Leptographium terebrantis, L. procerum), a combination (O. minus + L. terebrantis), or H2O as a control. Over four years, all fungi-inoculated trees formed lesions around injection sites, while control trees formed no lesions except for two contaminated control trees that were excluded from analyses. Bluestain-inoculated trees had increased termite presence in and around fungal lesions, whereas control trees had no termites present. Specifically, termites were present on 35 % of fungi-inoculated trees, presence was consistent over time, and there was no difference among fungal species. This study experimentally demonstrates a link between bluestain fungi and subterranean termites in forests, which could impact tree dynamics post-bluestain infection.

Consistent effects of eastern subterranean termites (Reticulitermes flavipes) on properties of a temperate forest soil

Termites inhabit a large portion of land covered by temperate forests. Climate warming and urbanization will likely extend their range and increase their densities in these ecosystems but, compared to their tropical counterparts, little is known about their effects on soil properties and processes. If temperate termites have the strong ecosystem engineering effects of tropical termites, then knowledge of their ecology and impacts will be vital for predicting how temperate systems respond to environmental change. We investigated how feeding and tunneling by the eastern subterranean termite, Reticulitermes flavipes, affected wood decomposition and soil properties under decaying wood. Twelve laboratory microcosms filled with mineral soil and with wood blocks of four common temperate tree species, received R. flavipes soldiers and workers at field densities, with an additional five termite-free microcosms serving as controls. After 25 weeks, the effects of termites on wood mass loss, and on carbon and nitrogen dynamics, differed across tree species, yet their effects on soil properties were consistent regardless of wood type. Microbially-available carbon in soil was 20% higher with termites and soil moisture content 20% lower. Soil pH was more acid with termites and their effects on soil microbial biomass were positive but non-significant. These soil responses were consistent regardless of the wood species, suggesting that termite effects on soil are dictated largely by their activity within the soil matrix and not by their feeding rate on specific wood substrates. These results are among the first to quantify the effects of temperate forest termite activity on soil properties, demonstrating the potential for these termites to shape biogeochemical cycling and plant communities through their alteration of the soil environment.

Temperate forest termites: ecology, biogeography, and ecosystem impacts

1. Wood decomposition in temperate forests is dominated by termites, fungi, and some species of ants and beetles. Outside of urban areas, temperate termite ecology is largely unknown, particularly when compared to tropical termites and other temperate organisms in the functional guild of wood‐decomposing animals.2. This review combines climate habitat modelling with knowledge of species physiology, behaviour, and community interactions to identify and prioritise future research on temperate termite ecology and biogeography.3. Using a correlative climate model, the regional distributions of three common temperate forest termite species are shown to correlate with different aspects of climate (e.g. mean versus minimum monthly temperature), but that overall their distributions within temperate systems correlate more strongly with temperature variables than with precipitation variables.4. Existing data are synthesised to outline how the subterranean, wood‐nesting behaviour of most temperate forest termite species links their activity to an additional set of non‐climate controls: wood type and tree species, soil depth, fungal activity, ant abundances and phenology, and competitive asymmetries among termite species.5. Although fine‐scale estimates of temperate termite abundances are rare, we provide upper bounds on their ecosystem impacts and illustrate how their regional abundances may influence forest structure and habitat availability for other organisms.6. This review highlights that rigorous ecological studies in non‐urban, intact ecosystems – with a particular focus on community interactions – are critically needed to accurately project future abundances, economic impacts, and ecosystem effects of temperate forest termites.

Latitudinal Variation in Termite Species Richness and Abundance along the Brazilian Atlantic Forest Hotspot

AbstractIn this study, we investigated the termites of the Brazilian Atlantic Forest, one of the most threatened biodiversity hotspots in the world, in regularly spaced sites from 7° S to 27° S latitude. To our knowledge, this is the only report of a latitudinal survey of termites at species level performed with a standardized sampling protocol. We evaluate termite diversity and abundance, and describe patterns of species composition based on feeding groups along the latitudinal gradient. We also describe the relative contribution of environmental variables to explain diversity patterns. Termite assemblages were investigated by standardized surveys at 15 Atlantic Forest sites, on six transects divided into five sections of 10 m², with 30 sections per site (or 300 m²/site), which were investigated by one trained person for one hour. Observed species richness and abundance were negatively correlated with latitude. The influence of latitude was explained mainly by variables related to temperature, precipitation and ambient energy (potential evapotranspiration). Our results also suggest that temperature exerts a greater constraint on Atlantic Forest termites than productivity, because ambient productivity increases with latitude in this forest but termite diversity decreases. Termite species richness in the Atlantic Forest showed a different pattern than those described for other organisms, increasing in diversity where the coastal‐forest strip narrows. Overall, our results indicate comparatively high termite species richness at northeastern sites and a significant impoverishment of termite assemblages in the southeastern and southern regions of the Atlantic Forest.

Distinctiveness of termite assemblages in two fragmented forest types in Hantane hills in the Kandy District of Sri Lanka

This study compares the termite assemblages in a natural and a secondary forest located at two different elevations in the Hantane hills, a tropical evergreen forest in mid country Sri Lanka, with a view to identify their distinctiveness. To sample the termites in the two forest types the belt transect method was used supplemented by random collections. A total of 11 species of termites in four genera belonging to three subfamilies and one family, Termitidae were recorded; nine species from the secondary forest and two species from the natural forest. The two species, Ceylonitermellus hantanae and Dicuspiditermes incola showed a distinct distribution in being confined only to the natural forest at high elevation. Termites recorded were put into feeding groups based on their taxonomic identity. Termites of the natural forest were found to be exclusively true soil feeders. Those of the secondary forest were wood feeders; either fungus growing (8 spp.) or non-fungus growing wood feeders (1 sp.). The high abundance and low diversity of the natural forest termite species in comparison to secondary forest species also make them distinct. Elevation, climate, vegetation, ground cover and the degree of human interference appear to contribute to the distinctiveness of termite assemblages in the two forests types reported here. Key words: natural forest; secondary forest; species diversity; functional groups; elevation DOI: 10.4038/cjsbs.v39i1.2349 Cey. J. Sci. (Bio. Sci.) 39 (1): 11-19, 2010

Lignin characteristics and density fractions of termite nests in an Amazonian rain forest—indicators of termite feeding guilds?

High termite abundance and diversity in rainforests results in the creation of different termite nests, which are formed from excreted food waste. The objective of this study was to elucidate the properties of nest material of common rain forest termites by analysing residues of potential food sources. In the Amazonian rain forest near Manaus, Brazil, we sampled nests of six different termite genera as well as surrounding wood, microepiphytes and soil. After a density separation into <1.6, 1.6–1.8, 1.8–2.0, 2.0–2.4, and >2.4 g cm −3 fractions, we determined the contents of C, N, and lignin-derived phenols in the samples. As particle density increased, the element and lignin concentrations decreased in all samples, the remaining lignin showed evidence of increased side-chain oxidation ( P<0.05). The termite nests contained 7.3–22 times more C, 14–220 more lignin-derived phenols, and 5.6–260 times more light fraction material than the surrounding surface soils (0–10 cm). The nests of the wood-feeding guild contained 1.2–15 times more lignin and 1.1–46 times more light material than those of the soil/wood-interface feeders. Among the different nests, the particle density increased in the order Nasutitermes sp.< Cornitermes sp.< Termes sp.< Embiratermes sp.< Anoplotermes sp. (<soil). In the same direction the content of lignin-derived phenols decreased from 111 to 3 g kg −1 nest material and amounted to 0.5 g kg −1 soil. The results indicated a shift from wood to soil material in the nests. Nests of Constrictotermes sp. had low lignin content despite high proportions of the light material. This indicated feeding on microepiphytes. We conclude that variations in lignin characteristics and density fractions of termite nests reflect differences in feeding guilds of the studied taxa.

Respiratory gas exchanges of termites from the Sabah (Borneo) assemblage

Abstract.Oxygen uptake and carbon dioxide release at 28°C were determined in worker castes of twenty‐six species of forest termites from the Danum Valley Conservation Area, south‐east Sabah, by Warburg manometry.Metabolic rate varied inversely with body weight in a suite of soil‐, wood/soil‐ and wood‐feeding species, giving a slope (in a log–log plot) of – 0.63. However, a number of large species, actively foraging forms such as Macrotermes malaccensis, M. gilvus, Havilanditermes atripennis and Hospitalitermes hospitalis, but also the wood‐feeding Schedorhinotermes sarawakensis, showed an oxygen consumption greater than expected for their body weight. Rates of methane emission were above 0.100 μmol g–1 h–1 in seventeen species, with very high fluxes in two wood/soil‐feeders, Termes borneensis (0.546 ± 0.163 μmol g–1 h–1) and Prohamitermes mirabilis (0.303 ± 0.123 μmol g–1 h–1). Of the fifteen remaining species, seven were soil‐feeders, five were wood‐feeders, two were wood/litter‐feeders and a single species fed on lichen and moss. Low or negligible CH4 emissions (&lt; 0.100 μmol g–1 h–1) were observed in three other species, all wood‐feeders.An apparent respiratory quotient (RQapp) was calculated using xCO2 and xO2 (corrected for methane emission, but not hydrogen). Mean RQapp was at or above 1.00 in eleven species and between 0.95 and 1.00 in a further six species, the two sets of species together representing all trophic groups, including lichen‐feeders. This is argued to be consistent with carbohydrate being the principal substrate supporting respiration.

Colony Populations and Biomass in Nests of the Amazonian Forest Termite Anoplotermes banksi Emerson (Isoptera: Termitidae)

The arboreal nests of the termite Anoplotermes banksi are abundant in Central Amazonian primary rain forests. Colony size of 7 nests (weight 92–6891 g) varied between 2,593 and 39,256 individuals/nest (1.5 – 22.1 g termites/nest). Average body fresh weight was 0.9 mg for workers and 2.1 mg for alates. Queens weighed 10–30 mg. No relationship between nest weight and maturity was detected, as the ratio of workers to larvae was 1:1, independent of nest size, and alates were found in nests weighing less than 200 g. Nests of A. banksi (12–18 ha -1) accounted for 12–15% of the nest density of all Isopteran species, but the calculated fresh weight of the termites of this species (15–23 mg/m 2) represented only 0.2–0.4% of the total termite biomass in the study area.