Fourteen months of seed rain in three Australian semi‐arid communities

The abundance and composition of seed rain was measured over 14 months (February 2004 to March 2005) in Currawinya National Park, western Queensland. The experimental design included four measurement periods, three vegetation communities and two grazing regimes. A total of 12 586 seeds from 104 species were captured. There were significantly more seeds and species captured during the measurement period with the least rainfall, although no significant correlation was found between the amount of rainfall and the number of seeds or species captured. More seeds and species were captured where native and feral grazing pressure was removed, but this was only significant for the number of species. The above‐ground vegetation showed no significant difference between grazing treatments over the study period and exhibited far fewer species than the seed rain. However, the majority of species found in the above‐ground vegetation were represented in the seed rain. Hypotheses are explored as an attempt to understand the apparent lack of a relationship between seed rain and rainfall. The effects of grazing and seed movement and storage are also discussed.     

Multiple GUS expression patterns of a single Arabidopsis gene

Ten independent transposant lines with gene or enhancer traps (ET) inserted into the same gene (At2g01170) were identified in Arabidopsis thaliana . Transposon insertions were confirmed for each line. Only three of five ET lines and only one of the five gene trap (GT) lines displayed uidA (GUS) staining. The GUS (β-glucuronidase) expression patterns of the ET lines were different in all three lines. In the GT line, the GUS expression was restricted to the vascular tissue under all conditions examined. The variation in ET GUS expression suggests that each ET was controlled by different enhancer elements or the different elements of the trapped locus may give rise to different GUS expression patterns. Of five GT lines, three have the GUS gene in the same orientation as the At2g01170 open reading frame, yet only one yielded GUS staining. Regardless of the insertion construct, only those transposants with an insertion at the 3' end of the gene yielded GUS staining. Some transposants displayed a longer root phenotype in the presence of kanamycin that was also observed in 3' insertion sites in At2g01170. Taken together, these data show that insertions in the 5' end of the gene disrupted expression and emphasise the complexity encountered with ET and GT constructs to characterise the expression patterns of genes of interest based solely on GUS expression patterns.     

Development and optimisation of a sex pheromone lure for monitoring populations of saddle gall midge,Haplodiplosis marginata

Saddle gall midge, Haplodiplosis marginata (von Roser) (Diptera: Cecidomyiidae), is a sporadic pest of cereals in Northern and Central Europe and is of increasing importance in the UK. Recently, the major component of the sex pheromone produced by adult female H. marginata was reported to be 2‐nonyl butyrate. The importance of absolute configuration on attractiveness, the effects on trap catches of the addition of minor pheromone components, dispenser type, and pheromone loading are described in the development of an optimised pheromone lure with which to trap H. marginata males. In analyses of volatiles collected from virgin female H. marginata by gas chromatography (GC) coupled with electroantennographic recording (EAG) from the antenna of a male H. marginata, two EAG responses were observed. Analyses by coupled GC‐mass spectrometry (MS) indicated these were due to 2‐nonyl butyrate and a trace amount (1%) of 2‐heptyl butyrate. A similar trace amount of 2‐nonanol was detected in GC‐MS analyses but this compound did not elicit an EAG response when the synthetic compound was tested, whereas the other two compounds did. These three compounds were not observed in collections of volatiles made from male H. marginata. The 2‐nonyl butyrate was shown to be the (R)‐enantiomer. In field trapping tests (R)‐2‐nonyl butyrate was at least 10× more attractive to male H. marginata than the racemic compound, and the (S)‐enantiomer was unattractive. Addition of the potential minor components individually or together at the naturally occurring ratios did not increase or reduce the attractiveness of the lure. Polyethylene vials and rubber septa were equally effective as pheromone dispensers, lasting for at least 5 weeks in the field in the UK, although laboratory tests indicated release from the former was more uniform and more likely to last longer in the field. Increasing loading of pheromone in the dispenser increased attractiveness. Traps baited with polyethylene vials containing 0.5 mg of (R)‐2‐nonyl butyrate are recommended for monitoring H. marginata and these are far more sensitive than water or sticky traps currently used for monitoring this pest.     

Trap style influences wild pig behavior and trapping success

Despite the efforts of many natural resource professionals, wild pig (Sus scrofa) populations are expanding in many areas of the world. Although many creative techniques for controlling pig populations are being explored, trapping has been and still is the most commonly used method of population control for many public and private land managers. We conducted an observational study to examine the efficiency of 2 frequently used trap styles: a small, portable box-style trap and a larger, semi-permanent, corral-style trap. We used game cameras to examine patterns of trap entry by wild pigs around each style of trap, and we conducted a trapping session to compare trapping success between trap styles. Adult female and juvenile wild pigs entered both styles of trap more readily than did adult males, and adult males seemed particularly averse to entering box traps. Less than 10% of adult male visits to box traps resulted in entries, easily the least percentage of any class at any style of trap. Adult females entered corral traps approximately 2.2 times more often per visit than box traps and re-entered corral traps >2 times more frequently. Juveniles entered and re-entered both box and corral traps at similar rates. Overall (all-class) entry-per-visit rates at corral traps (0.71) were nearly double that of box traps (0.37). Subsequent trapping data supported these preliminary entry data; the capture rate for corral traps was >4 times that of box traps. Our data suggest that corral traps are temporally and economically superior to box traps with respect to efficiency; that is, corral traps effectively trap more pigs per trap night at a lower cost per pig than do box traps. © 2011 The Wildlife Society.     

The search for common anthropogenic impacts on biodiversity: a global network

We introduce an initiative to assess and compare landscape changes related to human activities on a global scale, using a single group of invertebrates. The GLOBENET programme uses common field methodology (pitfall trapping), to appraise assemblages of ground beetles (Coleoptera, Carabidae) in visually-similar land-mosaics (urban-rural gradients). Carabids were selected as the focal taxon as they are sufficiently varied (both taxonomically and ecologically), abundant and sensitive to the environment. However, work on other taxa is comparable with the GLOBENET framework. The continuum of decreasing human pressure from city centres into the surrounding countryside was selected to represent human-caused disturbance for this initial stage of GLOBENET because these gradients can be found virtually all over the world. Through the broad-scale assessment envisioned in the GLOBENET programme, we seek to separate general, repeated effects on biodiversity from those that depend on local environments or particular biotic assemblages. Based on this understanding we aim to develop simple tools and protocols for assessing ecological effects of human-caused landscape changes, which could help to sustainably manage landscapes for biodiversity and for human requirements. For instance, the response of different functional groups of carabids to these landscape changes may help guide management practices. Further GLOBENET developments and information are available at our website: http://www.helsinki.fi/science/globenet/     

Weeding out the genes: the Arabidopsis genome project

The Arabidopsis genome sequence is scheduled for completion at the end of this year (December 2000). It will be the first higher plant genome to be sequenced, and will allow a detailed comparison with bacterial, yeast and animal genomes. Already, two of the five chromosomes have been sequenced, and we have had our first glimpse of higher eukaryotic centromeres, and the structure of heterochromatin. The implications for understanding plant gene function, genome structure and genome organization are profound. In this review, the lessons learned for future genome projects are reviewed as well as a summary of the initial findings in Arabidopsis. Electronic Publication