Local habitat and landscape affect Ixodes ricinus tick abundances in forests on poor, sandy soils

Abstract

A large fraction of the forests in northern Belgium consists of homogeneous pine stands on nutrientpoor and acid sandy soils. However, in common with many other parts of Europe, the current forest management aims at increasing the share of deciduous and mixed forests. This might create favourable habitats for the tick Ixodes ricinus, which is Europe's main vector of Borrelia burgdorferi sensu lato, the causative agent of Lyme borreliosis in humans. Considering the threat to human health, it is important to know which factors regulate tick abundance. The influence of local habitat and landscape variables on the abundance of I. ricinus ticks were studied by collecting questing larvae, nymphs, and adults at 176 locations in forests in the Campine region (northern Belgium). Both I. ricinus ticks and B. burgdorferi spirochetes occurred throughout the study area, which means that the entire region represents an area of risk for contracting Lyme borreliosis. At the forest stand level, the main tree species and the shrub cover significantly affected the abundance of all life stages of I. ricinus. The abundance was higher in oak stands compared to pine stands, and increased with increasing shrub cover. Additionally, at the landscape level, a positive effect was found for forest edge length but not for forest cover. These patterns may be explained by the habitat preferences of the tick's main hosts. Our results indicate that forest conversion might indeed create suitable habitats for ticks, which highlights the need for intensive information campaigns and effective tick control measures.

Distribuição espacial e abundância de carrapatos (Acari: Ixodidae) em remanescente de Mata Atlântica, Nordeste do Brasil

“…Além destes fatores, condições ambientais específicas produzidas pelo processo de fragmentação de habitats parecem ser capazes de influenciar a distribuição agregada de carrapato (Tack et al 2012). No estudo realizado por Tack et al (2012), foi observado uma maior abundância de carrapatos em fragmentos com maiores habitats de borda.…”

Free-living ixodid ticks in an urban Atlantic Forest fragment, state of Rio de Janeiro, Brazil

“…Some studies have shown a correlation between tick abundance and the environment (ARZUA, 2007;JAENSON et al, 2009;TACK et al, 2012). However, whatever differences are found appear to be more related to the presence of hosts than to the actual structure of the landscape (ESTRADA-PEÑA, 2003;ALLAN et al, 2003;BROWNSTEIN et al, 2005;TACK et al, 2012).…”

“…Because forest areas may differ from open habitats such as grasslands, in terms not only of vegetation type but also weather patterns (ARZUA, 2007;TACK et al, 2012), an analysis was also made of the abundances of species found as a function of micro-and mesoclimatic conditions. Curió Municipal Nature Park (Curió Park) (22°33' -22°36' S and 43°40' -43°43' W) is a Full Protection Conservation Unit, located in the municipality of Paracambi, Rio de Janeiro state, Brazil.…”

“…In southeastern Brazil, these areas correspond to Atlantic Forest remnants, which are favorable environments for ticks due to their abiotic and biotic characteristics, such as high percentages of relative humidity and moderate temperatures, allied to the presence of natural hosts (TACK et al, 2012). Some studies have shown a correlation between tick abundance and the environment (ARZUA, 2007;JAENSON et al, 2009;TACK et al, 2012).…”

“…In southeastern Brazil, these areas correspond to Atlantic Forest remnants, which are favorable environments for ticks due to their abiotic and biotic characteristics, such as high percentages of relative humidity and moderate temperatures, allied to the presence of natural hosts (TACK et al, 2012). Some studies have shown a correlation between tick abundance and the environment (ARZUA, 2007;JAENSON et al, 2009;TACK et al, 2012). However, whatever differences are found appear to be more related to the presence of hosts than to the actual structure of the landscape (ESTRADA-PEÑA, 2003;ALLAN et al, 2003;BROWNSTEIN et al, 2005;TACK et al, 2012).…”