scholarly journals Assessing the Australian Termite Diversity Anomaly: How Habitat and Rainfall Affect Termite Assemblages

2021 ◽  
Vol 9 ◽  
Author(s):  
Rebecca A. Clement ◽  
Habacuc Flores-Moreno ◽  
Lucas A. Cernusak ◽  
Alexander W. Cheesman ◽  
Abbey R. Yatsko ◽  
...  
Keyword(s):  
Dead Wood ◽  
Annual Rainfall ◽  
Tropical Rainforests ◽  
Termite Species ◽  
Tropical Regions ◽  
Feeding Groups ◽  
Feeding Group ◽  
Grass Litter ◽  
High Precipitation ◽  
Group Diversity

Termites are important ecosystem engineers in tropical habitats, with different feeding groups able to decompose wood, grass, litter, and soil organic matter. In most tropical regions, termite abundance and species diversity are assumed to increase with rainfall, with highest levels found in rainforests. However, in the Australian tropics, this pattern is thought to be reversed, with lower species richness and termite abundance found in rainforest than drier habitats. The potential mechanisms underlying this pattern remain unclear. We compared termite assemblages (abundance, activity, diversity, and feeding group composition) across five sites along a precipitation gradient (ranging from ∼800 to 4,000 mm annual rainfall), spanning dry and wet savanna habitats, wet sclerophyll, and lowland and upland rainforests in tropical North Queensland. Moving from dry to wet habitats, we observed dramatic decreases in termite abundance in both mounds and dead wood occupancy, with greater abundance and activity at savanna sites (low precipitation) compared with rainforest or sclerophyll sites (high precipitation). We also observed a turnover in termite species and feeding group diversity across sites that were close together, but in different habitats. Termite species and feeding group richness were highest in savanna sites, with 13 termite species from wood-, litter-, grass-, dung-, and soil-feeding groups, while only five termite species were encountered in rainforest and wet sclerophyll sites—all wood feeders. These results suggest that the Australian termite diversity anomaly may be partly driven by how specific feeding groups colonized habitats across Australia. Consequently, termites in Australian rainforests may be less important in ecosystem processes, such as carbon and nutrient cycling during decomposition, compared with termites in other tropical rainforests.

scholarly journals Response of termite communities to natural forest conversion

2021 ◽  
Vol 22 (11) ◽  
Author(s):  
Sri Heriza ◽  
DAMAYANTI BUCHORI ◽  
IDHAM SAKTI HARAHAP ◽  
NINA MARYANA
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Dead Wood ◽  
Natural Forest ◽  
Forest Conversion ◽  
Plantation Forest ◽  
Termite Species ◽  
Land Use Conversion ◽  
Feeding Groups ◽  
Land Use Types

Abstract. Heriza S, Buchori D, Harahap IS, Maryana N. 2021. Response of termite communities to natural forest conversion. Biodiversitas 22: 5092-5096. Natural forest conversion can affect termite communities resulting from the various types of land use conversion. This study aims to examine the impacts of natural forest conversion on termite communities based on species richness, feeding groups, and termite species composition. Four land use types were evaluated on a gradient from the least to the most disturbing: natural forest, plantation forest, oil palm plantations and settlements. The method used to observe termites in this study is a plot measured 50 m x 10 m and was divided into sub-plots of 5 m x 5 m. The termites were collected from leaf litter and soil, dead wood, trunks, and nests. The response of the termite community to the conversion of natural forest functions into other forms of land use types, where for termite species richness, there was no significant differences between land uses, but for abundance and based on feeding groups there were difference between them.

scholarly journals Termite Diversity in Ecuador: A Comparison of Two Primary Forest National Parks

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Cecilia A L Dahlsjö ◽  
Cynthia S Valladares Romero ◽  
Carlos-Iván Espinosa Iñiguez
Keyword(s):  
Species Richness ◽  
National Parks ◽  
Primary Forest ◽  
Comparable Data ◽  
Termite Species ◽  
Feeding Group ◽  
Forest Sites ◽  
The Difference ◽  
Termite Ecology ◽  
Group Diversity

Abstract Termites are one of the key ecosystem engineers in tropical forests where they play a major role in decomposition rates, both above and belowground. The interest in termite ecology and biogeography has increased in the last few decades; however, the lack of comparable data has limited the wider impact of termite research. For Ecuador, termite studies are relatively rare and comparable data that are collected using standardized sampling methods are missing. In this study, we aim to 1) provide comparable data of termite species and feeding-group diversity from two primary forests in Ecuador and 2) explore the differences in termite species and feeding-group diversity between the two forest sites. Sampling took place in the national parks of Yasuní and Podocarpus where three belt transects (100 × 2 m) following Jones and Eggleton (2000) were conducted in each forest. We found that termite species richness was higher in Yasuní (56 species) than in Podocarpus (24 species) and that 57% of the sampled termite genera had never previously been recorded in Ecuador. The inter-site species dissimilarity was almost complete (Bray Curtis (±SD), 0.91 ± 0.01), which may have been linked to the difference in tree density and species richness in the two forests. Termite feeding-groups diversity was significantly higher in Yasuní than in Podocarpus with the exception of soil-feeding termites which may have been due to competition between humus- and soil-feeding species.

Invasive Syzygium jambos trees in Puerto Rico: no refuge from guava rust

2017 ◽  
Vol 33 (3) ◽  
pp. 205-212 ◽  
Author(s):  
Erin Burman ◽  
James D. Ackerman ◽  
Raymond L. Tremblay
Keyword(s):  
Puerto Rico ◽  
Species Distribution Modelling ◽  
Negative Consequences ◽  
Tropical Regions ◽  
Mountainous Regions ◽  
Syzygium Jambos ◽  
Guava Rust ◽  
Invasive Tree ◽  
High Precipitation ◽  
Austropuccinia Psidii

Abstract:Biological invasions can have negative consequences for resident biota, particularly when disease-causing organisms are involved. Austropuccinia psidii, or guava rust, has rapidly spread through the tropics affecting both native and non-native Myrtaceae. In Puerto Rico, the rust has become common on Syzygium jambos, an invasive tree native to South-East Asia. What are the drivers of infection, and do refugia exist across a heterogeneous landscape? We address these questions using species distribution modelling and beta regressions. The realized and potential distribution of Syzygium jambos is extensive. The model produced an AUC of 0.88, with land-use categories and precipitation accounting for 61.1% of the variation. Predictability of S. jambos is highest in disturbed habitats, especially in mountainous regions with high precipitation. All 101 trees surveyed and measured across Puerto Rico showed signs of infection to varying extents. Infection severity was consistently associated with annual mean temperature in all top beta regression models, but was also commonly associated with tree size and precipitation variables. We found no safe sites for S. jambos. Many trees were extremely unhealthy and some were dead, suggesting that S. jambos may soon become extinct on the island or reduced to persistent stump sprouts. Native vegetation may benefit from the local demise of S. jambos. While the rust has not jumped to native Myrtaceae, vigilance is required, as host-shifts have occurred in other tropical regions.

Effect of tropical weathering on electrical and electromagnetic measurements

Geophysics ◽  
1979 ◽  
Vol 44 (1) ◽  
pp. 69-88 ◽  
Author(s):  
G. J. Palacky ◽  
Kiyoshi Kadekaru
Keyword(s):  
Electrical Properties ◽  
Mineral Exploration ◽  
Annual Rainfall ◽  
Tropical Regions ◽  
Rock Types ◽  
Electromagnetic Measurements ◽  
Weathered Layer ◽  
Efficient Exploration ◽  
Effective Use ◽  
Airborne Em

Electrical properties of the weathered layer in tropical regions of Brazil were investigated by means of resistivity soundings, airborne, and ground electromagnetic measurements. Five case histories illustrate how changes of climate, lithology, and geomorphology affect geophysical measurements. In humid and subhumid tropical regions (annual rainfall over 650 mm) the weathered layer is between 10 and 80 m thick and moderately conductive. Results from one region (Minas Gerais) indicate that excessive depth of weathering and leaching of massive sulfides, rather than the conductivity of overburden, present the greatest obstacle to effective use of airborne EM methods in mineral exploration. Seasonal variations of precipitation cause changes in soil resistivity, but such changes are not apparent in the underlying weathered layer. In semiarid and temperate regions of Brazil, the weathered layer is 10 to 20 m thick and regional airborne EM surveys are an efficient exploration tool. In all regions, the degree of weathering depends upon lithology and, in several areas, anomaly patterns obtained from airborne EM surveys correlate well with the surface geologic map. However, when comapring electrical properties of similar rock types among regions of the same climatic type, a considerable variation is observed. It seems that also geomorphology plays an important role in weathering. A careful interpretation of airborne EM data is necessary to distinguish anomalies caused by the weathered layer from those due to underlying conductors. Highly conductive, saline alluvia, which cause strong EM anomalies in Australia, were encountered (sporadically) in only one region of Brazil, the semiarid Valley of Curaçá, Bahia.

In defence of small habitat islands: Termites (Isoptera) in the Western Australian central wheatbelt, and the importance of dispersal power in species occurrence

2000 ◽  
Vol 6 (1) ◽  
pp. 31 ◽  
Author(s):  
Max Abensperg-Traun ◽  
Max Abensperg-Traun
Keyword(s):  
Dead Wood ◽  
Common Species ◽  
Species Number ◽  
Termite Species ◽  
South West ◽  
Trees On Farms ◽  
Habitat Islands ◽  
Spatial Isolation ◽  
Isolation Effects ◽  
Western Australian

Ecological theory has long undervalued the contribution of small remnants of native vegetation to nature conservation. This study provides data on colony persistence of remnant-dependent wood-eating termites in 28 remnants of mature wandoo (Eucalyptus capillosa) trees in paddock situations in the agricultural south-west of Western Australia. Remnants ranged in size from 2 to 30 trees, and in spatial isolation from 50 to 650 m. All remnants have been exposed to livestockrelated disturbance for >40 years. This study found that (1) Small remnants of eucalypt trees on farms retain important functional representatives, i.e., wood-eating termites for nutrient-cycling, and high species numbers. (2) Seventeen species have the capacity to establish and maintain colonies in remnants =5 trees. (3) Spatial isolation has no significant influence on the total number of termite species. (4) The number of trees (r = 0.60) and quantity of dead wood in the remnant (r = 0.86) were significant indicators of total termite species number. Larger remnants with low quantities of wood supported few termites, however. (5) Rare as well as common species persisted in small remnants. (6) Alate wing-size was a significant indicator of the occurrence of the six most common termite species in remnants (r = 0.84). The implication of isolation effects for rare species with limited powers of dispersal is self-evident, as is the need for the creation of habitat linkeages to reduce the effects of spatial isolation on the native fauna.

What controls erosion (exhumation) along the humid eastern margin of the Northern Andes? Insights from U-Th/He thermochronology

2020 ◽  
Author(s):  
Nicolas Perez-Consuegra ◽  
Edward R Sobel ◽  
Andres Mora ◽  
Jose R Sandoval ◽  
Paul G Fitzgerald ◽  
...  
Keyword(s):  
Middle Part ◽  
Tropical Regions ◽  
Northern Andes ◽  
Mountain Ranges ◽  
Mountainous Regions ◽  
Relative Contribution ◽  
Tectonically Active ◽  
Exhumation Rates ◽  
High Precipitation ◽  
Channel Steepness

<p>The relative controls of rock uplift (tectonics) and precipitation (climate) on the exhumation of earth’s rocks in tectonically active mountain ranges are still debated. In low latitude tropical regions where rates of precipitation and the amount of vegetation cover are higher, more data is required to test the relative contribution of these factors to the evolution of orogenic topography. To contribute to this debate, cooling ages were derived for 25 bedrock and four detrital samples using the apatite (U-Th-Sm)/He (AHe) low temperature thermochronometer. AHe ages are reported along a ~450-km-wide swath on the eastern flank of the Northern Andes in Colombia (South America). The AHe cooling ages, that range from 2.5 Ma to 17 Ma, are compared to precipitation rates and geomorphic parameters in order to discern the relative importance of climate and/or tectonics on exhumation. Along the transect, AHe cooling ages are poorly correlated with the rates of precipitation but show a good correlation with landscape parameters such as average hillslope and average channel steepness. Moreover, young AHe cooling ages coincide with areas where deformation is mainly compressional; older AHe cooling ages are found in the middle part of the study area where strike-slip deformation dominates. The spatial distribution of the new AHe cooling ages suggests that in mountainous regions, in this case with high precipitation rates (> 1500 mm/yr), denudation is mainly controlled by the rate of vertical advection of material via tectonic processes. The spatial variations in precipitation may only have a second-order role in modulating exhumation rates.</p>

scholarly journals Precipitation Patterns and Rainfall Erosivity Return Period Under Savanna Conditions in Formosa, Goiás, Brazil

2020 ◽  
Vol 8 (4) ◽  
pp. 554
Author(s):  
Aline Franciel de Andrade ◽  
Roriz Luciano Machado ◽  
Cássia Cristina Rezende ◽  
Elizabete Alves Ferreira ◽  
Daniel Fonseca de Carvalho ◽  
...  
Keyword(s):  
Annual Rainfall ◽  
Rainfall Erosivity ◽  
Return Periods ◽  
Tropical Regions ◽  
Average Annual Rainfall ◽  
Physical Attributes ◽  
Erosivity Index ◽  
Rainfall Patterns ◽  
Agricultural Areas ◽  
Intermediate Pattern

Losses of soil and nutrients affect a large part of agricultural areas in tropical regions, regardless of the level of technology adopted. This study evaluated the physical attributes and erosivity indices associated with rainfall patterns and return periods in the region of Formosa, State of Goiás, Brazil. Using series of pluviographic (2002-2008) and pluviometric (1975-1998) data from a station located at municipality of Formosa, the erosive potential (EI30 and KE>25), rainfall patterns (advanced, intermediate and delayed) and the erosivity associated with the rainfall return periods were determined. The average annual rainfall of the region was 1,391.6 mm with 87.4% of the rains concentrated in October to March. The average annual values of EI30 and KE>25 corresponded to 8,041.6 MJ mm ha-1 h-1 year-1 and 125.7 MJ ha-1 year-1, respectively. The months of the year did not differ based on rainfall pattern. The advanced hydrological pattern had the highest frequency of occurrence, followed by the delayed and intermediate patterns. The highest EI30 and KE>25 indices for individual rainfall seasons occurred under the intermediate and the advanced patterns in February and under the intermediate pattern in October for the index KE>25. The average annual erosivity index (R factor of USLE) (8041.6 MJ mm ha-1 h-1 year-1) is expected to occur at least once every 1.89 years, corresponding to a probability of occurrence of 52.84%. The average annual values of EI30 estimated for the return periods of 2, 5, 10, 25, 50 and 100 years were 8,230, 10,225, 10,889, 11,222, 11,421 and 11,488 MJ mm ha-1 h-1 year-1, respectively.

scholarly journals Termite Communities in Sugarcane Plantations in Southeastern Brazil: an Ecological Approach

2015 ◽  
Vol 8 (2) ◽  
pp. 105-116 ◽  
Author(s):  
Luciane Kern Junqueira ◽  
Edmilson Ricardo Gonçalves ◽  
Lucas Manuel Cabral Teixeira
Keyword(s):  
Functional Groups ◽  
Pest Control ◽  
Sugar Cane ◽  
Sao Paulo ◽  
Southeastern Brazil ◽  
Economic Losses ◽  
Correct Identification ◽  
São Paulo ◽  
Termite Species ◽  
Grass Litter

Termites are key components of soil fauna, playing an essential role in organic matter decomposition and nutrient cycling. However, they can cause significant economic losses in commercial plantations, such as sugar cane. Therefore, the correct identification of termite species is critical for pest control. Here, we evaluated the species richness, abundance and functional groups of termites in sugarcane plantations in 53 cities throughout the state of São Paulo, southeastern Brazil. We also analyzed the influence of macroclimatic variables on termite species distribution and functional groups. We found 22 taxa of two families, of which the most frequent species were Termitidae (96.51%). Within this family, Apicotermitinae had the highest frequency of occurrence (37.12%), followed by Termitinae (30.57%), Syntermitinae (27.95%), and Nasutitermitinae (0.8 %). The other family, Rhinotermitidae, had the lowest frequency (3.5%), being represented only by Heterotermes sulcatus Mathews. We classified Neocapritermes opacus Hagen (29.26%), Apicotermitinae sp.2 (24.89%), Cornitermes cumulans Kollar (13.10%), and Apicotermitinae sp.1 (6.99%) as common taxa. The remaining 18 species were classified as rare. The most common functional group was humus-feeders (37%), followed by wood-feeders (34%), grass-litter feeders (25%), and intermediate feeders (4%). Climate influenced the distribution of common species, humus-feeders and grass-litter feeders. Regarding the pest status of termites in sugar cane plantations, we suggest that the exasperated use of pesticide in the last decades has reduced the abundance of species considered pests (e.g. Heterotermes) and reinforce the importance of ecological approaches for determining the best pest control methods.Comunidades de Cupins em Cultivos de Cana-de-Açúcar no Estado de São Paulo: Uma Abordagem EcológicaResumo. Os cupins são importantes componentes da fauna de solo, atuando na decomposição da matéria orgânica e ciclagem de nutrientes. Porém, em cultivos de cana-de-açúcar, podem provocar perdas econômicas significativas. A correta identificação das espécies de cupins é um ponto crítico para o controle daquelas que adquiriram e/ou que podem atingir o status de praga. Este trabalho objetivou identificar a riqueza, a abundância e os grupos funcionais destes insetos em canaviais de 53 municípios do estado de São Paulo. Paralelamente, avaliou se as variáveis macroclimáticas influenciam a distribuição das comunidades de cupins e dos grupos funcionais. A riqueza obtida foi de 22 táxons. Da família Termitidae (96,51%), a maior frequência de ocorrência foi da subfamília Apicotermitinae (37,12%), seguindo-se Termitinae (30,57%), Syntermitinae (27,95%) e Nasutitermitinae (0,8%). A família Rhinotermitidae (3,5%) esteve representada apenas por Heterotermes sulcatus Mathews. Quatro táxons foram considerados comuns em canaviais, Neocapritermes opacus Hagen (29,26%), Apicotermitinae sp.2 (24,89%), Cornitermes cumulans Kollar (13,10%) e Apicotermitinae sp.1 (6,99%) e os 18 restantes foram classificados como raros. O grupo funcional mais frequente foi o dos humívoros (37%), seguido por xilófagos (34%), comedores de serrapilheira (25%) e intermediários (4%). O clima influenciou a distribuição das espécies comuns, bem como dos grupos funcionais dos humívoros e dos comedores de serrapilheira. Sugere-se que o uso intensivo de pesticidas nas últimas décadas reduziu a abundância de espécies até então consideradas praga em cana-de-açúcar (ex. Heterotermes), o que reforça a importância dos estudos ecológicos para a definição de métodos de controle mais adequados.

scholarly journals Mechanisms determining relationships between feeding group size and foraging success in food patch use by Japanese macaques (Macaca fuscata)

Behaviour ◽  
2010 ◽  
Vol 147 (11) ◽  
pp. 1481-1500 ◽  
Author(s):  
Nobuko Kazahari ◽  
Naoki Agetsuma
Keyword(s):  
Group Size ◽  
Feeding Rate ◽  
Japanese Macaques ◽  
Feeding Competition ◽  
Foraging Success ◽  
Feeding Groups ◽  
Social Monitoring ◽  
Monitoring Frequency ◽  
Feeding Group ◽  
Group Members

AbstractWe evaluated the effects of social monitoring and feeding competition on foraging success in relation to the feeding group size of wild Japanese macaques (Macaca fuscata). Social monitoring is visual scanning by group members that assists them in following their own group. Individuals in smaller feeding groups may frequently use social monitoring while foraging, because they have an increased risk of losing their group. Therefore, social monitoring could be a cost for group-foraging animals. We made four predictions: (1) individuals in smaller feeding groups tend to abandon food patches to follow group members; (2) social monitoring frequency is higher in smaller feeding groups; (3) feeding rate decreases with increased social monitoring frequency; and (4) feeding rate initially increases with feeding group size because decreased social monitoring outweighs increased feeding competition, but after the feeding group reaches a certain size, feeding rate declines with increasing feeding group size due to the high costs of feeding competition. These predictions were supported by our results. Thus, the relationship between feeding group size and feeding rate can show three patterns (positive, neutral and negative) in response to the balance between the costs of social monitoring and feeding competition.

Sign in / Sign up

Export Citation Format

Share Document