Small-mammal recolonization of open-forest following sand mining

Changes during regeneration after sand mining for heavy minerals were studied on an area that previously supported open-forest on the Holocene high dune system in Myall Lakes National Park. Sixteen study areas, on which topsoil was replaced 0.5–10 yr ago, provided information on changes to be expected on any one site over that time period. A number of environmental variables was used in a linear multiple regression analysis to determine which of them is important in accounting for the variance and patterns observed in the biomass of two rodent species colonizing the regenerating areas. The first small-mammal colonist is the introduced house mouse (Mus musculus), an opportunistic species present on all sites. Its population density increases rapidly to a maximum at 3 yr after which it declines. Three environmental variables: percentage of bare sand, hardness of the soil in the first 30 cm, and a vegetation structure variable, account for 73% of the variance in M. musculus biomass. The native New Holland mouse (Pseudomys novaehollandiae) first appears between 4 yr and 5 yr after topsoil replacement and peaks between 8 yr and 9 yr, after which it also declines. A highly significant multiple regression accounts for 69% of the variance in P. novaehollandiae biomass using five significant variables: the proportíon of heath plants present, two vegetation structure variables, the amount of dead plant cover, and the topsoil depth. The species replacement observed confirms the succession indicated by previous work and suggests competitive interaction between these species. This study confirms the seral positions of rodent species in successions following both mining or fire. There is a stretched time axis for the mining succession following the more complete disruption of the substrate so regeneration more closely approximates primary rather than secondary succession. The non-linearity of the parameters makes it impossible to predict a recovery time and verifies our previous prediction that recovery estimates from heathland should not be extrapolated to forest.     

Growth and photosynthesis of two eucalypt species during high temperature stress under ambient and elevated [CO2]

Two species of eucalypt (Eucalyptus macrorhyncha and E. rossii) were grown under conditions of high temperatures (45 °C, maximum) and high light (1500 μmol m^?2 s^?1, maximum) at either ambient (350 μL L^?1) or elevated (700 μL L^?1) CO₂ concentrations for 8 weeks. The growth enhancement, in terms of total dry weight, was 41% and 103% for E. macrorhyncha and E. rossii, respectively, when grown in elevated [CO₂]. A reduction in specific leaf area and increased concentrations of non-structural carbohydrates were observed for leaves grown in elevated [CO₂]. Plants grown in elevated [CO₂] had an overall increase in photosynthetic CO₂ assimilation rate of 27%; however, when measured at the same CO₂ concentration a down-regulation of photosynthesis was evident especially for E. macrorhyncha. During the midday period when temperatures and irradiances were maximal, photosynthetic efficiency as measured by chlorophyll fluorescence (F_v/F_m) was lower in E. macrorhyncha than in E. rossii. Furthermore, F_v/F_m was lower in leaves of E. macrorhyncha grown under elevated than under ambient [CO₂]. These reductions in F_v/F_m were accompanied by increases in both photochemical (qP) and nonphotochemical quenching (qN and NPQ), and by increases in the concentrations of xanthophyll cycle pigments with an increased proportion of the total xanthophyll cycle pool comprising of antheraxanthin and zeaxanthin. Thus, increased atmospheric [CO₂] may enhance photoinhibition when environmental stresses such as high temperatures limit the capacity of a plant to respond with growth to elevated [CO₂].     

Terrestrial Activity in Pitheciins (Cacajao,Chiropotes, and Pithecia)

Neotropical monkeys of the genera Cacajao, Chiropotes, and Pithecia (Pitheciidae) are considered to be highly arboreal, spending most of their time feeding and traveling in the upper canopy. Until now, the use of terrestrial substrates has not been analyzed in detail in this group. Here, we review the frequency of terrestrial use among pitheciin taxa to determine the ecological and social conditions that might lead to such behavior. We collated published and unpublished data from 14 taxa in the three genera. Data were gleaned from 53 published studies (including five on multiple pitheciin genera) and personal communications of unpublished data distributed across 31 localities. Terrestrial activity was reported in 61% of Pithecia field studies (11 of 18), in 34% of Chiropotes studies (10 of 29), and 36% of Cacajao studies (4 of 11). Within Pithecia, terrestrial behavior was more frequently reported in smaller species (e.g. P. pithecia) that are vertical clingers and leapers and make extensive use of the understory than in in the larger bodied canopy dwellers of the western Amazon (e.g. P. irrorata). Terrestrial behavior in Pithecia also occurred more frequently and lasted longer than in Cacajao or Chiropotes. An apparent association was found between flooded habitats and terrestrial activity and there is evidence of the development of a “local pattern” of terrestrial use in some populations. Seasonal fruit availability also may stimulate terrestrial behavior. Individuals also descended to the ground when visiting mineral licks, escaping predators, and responding to accidents such as a dropped infant. Overall, the results of this review emphasize that terrestrial use is rare among the pitheciins in general and is usually associated with the exploitation of specific resources or habitat types. Am. J. Primatol. 74:1106‐1127, 2012. © 2012 Wiley Periodicals, Inc.     

Plasmodium berghei NK65 in the Inbred A/J Mouse: Age Immunity in the Female Retired Breeder A/J Mouse*

SYNOPSIS. Death rates of A/J and CF₁ female mice 4 weeks and 6 months of age were compared after the mice were infected with Plasmodium berghei NK65C deme (population) and NK65RR deme. Death rates were compared also when female A/J retired breeder mice were infected with blood passages 18 and 40 of NK65C. NK65C was found to be less virulent than NK65RR. The 40th blood passage of NK65C was more virulent than the 18th passage, but still not as virulent at the NK65RR deme. A/J retired breeders were clearly more resistant to infection than 4 week old A/J mice, while little difference was found in the different age groups of the CF₁ mice.     

Characterization of Fusobacterium Species Isolated from Soft Tissue Infections in Cats

A total of 35 strains of Gram negative anaerobes, belonging to the genus Fusobacterium and isolated from subcutaneous abscesses and pyothorax in cats, have been examined morphologically and biochemically. Gas chromatography and biochemical analysis placed them into four species— Fusobacterium necrophorum (seven strains), F. russii (22 strains), F. naviforme (four strains) and F. nucleatum (two strains). It is considered that subcutaneous abscesses and pyothorax result from contamination from the oral cavity and upper respiratory tract. The disproportionate numbers of isolation of F. russii may reflect differences in the predominant flora in this region of cats compared to man. The ambiguity of the concept in current literature of the ability of organisms to convert threonine to propionate is discussed.     

Acetone Production as a Result of Sodium Bisulfate Preservation of Soil Samples

The use of sodium bisulfate for field preservation of soil samples collected for the analysis of volatile organics (VOCs) can result in the formation of acetone. The work was performed at Camp Edwards, Massachusetts, as part of a multi-year investigation of the effects of training activities on the local environment. Preservation with sodium bisulfate was initiated in 1999 under regulatory mandate. The frequency of acetone detection and the quantities reported increased immediately thereafter. Correlation of duplicate sample results and a side-by-side comparison of six sample handling methods involving two analytical laboratories suggest the interaction of sodium bisulfate with naturally occurring organic matter in samples from Camp Edwards cause the formation of acetone. The data also indicate that a higher content of natural organic matter results in a greater production of acetone, and more acetone is formed the longer the sodium bisulfate is in contact with the soil.