Trade-offs between succulent and non-succulent epiphytes underlie variation in drought tolerance and avoidance.

Epiphyte communities comprise important components of many forest ecosystems in terms of biomass and diversity, but little is known regarding trade-offs that underlie diversity and structure in these communities or the impact that microclimate has on epiphyte trait allocation. We measured 22 functional traits in vascular epiphyte communities across six sites that span a microclimatic gradient in a tropical montane cloud forest region in Costa Rica. We quantified traits that relate to carbon and nitrogen allocation, gas exchange, water storage, and drought tolerance. Functional diversity was high in all but the lowest elevation site where drought likely limits the success of certain species with particular trait combinations. For most traits, variation was explained by relationships with other traits, rather than differences in microclimate across sites. Although there were significant differences in microclimate, epiphyte abundance, and diversity, we found substantial overlap in multivariate trait space across five of the sites. We found significant correlations between functional traits, many of which related to water storage (leaf water content, leaf thickness, hydrenchymal thickness), drought tolerance (turgor loss point), and carbon allocation (specific leaf area, leaf dry matter content). This suite of trait correlations suggests that the epiphyte community has evolved functional strategies along with a drought avoidance versus drought tolerance continuum where leaf succulence emerged as a pivotal overall trait.

Ticks and haemoparasites of dogs from Praia, Cape Verde.

In February 2008 an epidemiological field study on arthropod-borne infections in dogs was carried out in Praia, the capital city of Cape Verde. For this purpose 130 dogs were included in the study. Of these, 94.6% were infested with ticks. Altogether, 1293 ticks of the genus Rhipicephalus (in all evaluated cases R. sanguineus) were collected. Examination for haemotropic parasites was performed via polymerase chain reaction (PCR). Lymph node fine-needle aspirates were screened by PCR for Leishmania infantum infections in 20 dogs with enlarged lymph nodes. Our investigation revealed two species of protozoa (Babesia canis vogeli and Hepatozoon canis) and two species of rickettsiae (Anaplasma platys and Ehrlichia canis). In 101 dogs (77.7%) DNA of one or more pathogens was detected. The PCR examination for H. canis was positive in 83 dogs (63.8%), for E. canis in 34 dogs (26.2%), for A. platys in 10 dogs (7.7%) and for B. canis in five dogs (3.8%), whereas neither B. gibsoni nor L. infantum DNA could be detected. Of the infected dogs, 71.3% had a monoinfection, 27.7% had infections with two pathogens and 1.0% with three pathogens. B. canis, H. canis, E. canis, A. platys and their vector tick R. sanguineus are endemic to Cape Verde and can be present in dogs in high prevalences. These results outline the risk of importing tropical canine diseases when Capeverdian stray dogs are taken to Europe.