Jack Lee Lincoln University, Canterbury, New Zealand . An investigation of species sorting and neutral processes during early colonisation of aquatic microcosms. Jack Lee Lincoln University, Canterbury, New Zealand . I’d remove Canterbury, New Zealand, this is pretty obvious to your audience anyway

Bacterial Immigration.... About 54,000 Kiwi’s migrated to Australia last year. However, c. 1.34 x 1015 (1.34 quadrillion) bacterial cells enter NZ on Australian dust particles each year! Limited knowledge of the impact! Perfect!! 134000 metric tonnes of dust from Oz to NZ each year (Marx et al .,2009). Very conservative estimate of 104 bacterial cells per gram = 1338550000000000 bacterial cells a year!

Neutral Processes Vs Species Sorting… TRY TO MENTION STERILE ENVIRONMENTS AS YOU TALK ABOUT THIS – GET THE AUDIENCE READY FOR THE NEXT SLIDE Stress impot Neutral Processes- Random migration, deaths, births, ‘speciation’. Species Sorting- Niche based sorting. Deterministic environmental selection

Investigate the effects of different immigration times in both pre-sterilised and non-sterilised microcosms. A 23L pH 7.8 B 150L pH 7.4 C 550L pH 7.1 Water = PS NS Inoculate = STILL THINK PS AND NS SHOULD BE ADDED TO THE TITLE (IN BRACKETS) Time = Water x 3 (A,B,C), Inoculate x 2 (PS, NS), Time x 7, Rep x 3 = 108 microcosms

Methods All samples collected after 7 days. All water filtered. ARISA PCR DNA Extraction Ordination diagrams generated and experimental treatments compared (MDS plots). ARISA performed

Neutral theory predicts... Pre-Sterilised microcosms will show no significant differences in community structure relating to pond water source (A,B or C). Pre-Sterilised Non-Sterilised Key: = A = B = C = Rain Process Pre-Sterilised Non- Sterilised Neutral Theory  MAKE THE WORDS COMMUNITY STRUCTURE STAND OUT MORE. IT LOOKS LIKE THERE IS NO DIFFERENCE (A VERSUS B AND C) WHEN YOU LOOK AT PS, SO YOU’LL HAVE TO EMPHASISE THAT THERE ARE SIGNIFICNAT TRENDS, BUT THAT THEY ARE WEAKER THAN FOR NS Significant differences between the two inoculates (PS and NS). Significant differences between the water samples (A, B and C) for both NS inoculates and PS inoculates. Significant differences in variability between PS samples, with A showing higher dissimilarity, and C showing the highest similarity. 2D stress 0.2 Based on a Bray-Curtis similarity matrix

Neutral theory predicts... There will be no significant differences in community evenness relating to pond water source. Source of variation d.f SS F P (i) PS Sample Data A v B 1 4.3 0.18 0.69 A v C 22.2 0.83 0.40 B v C 0.70 (ii) NS Sample Data 146 4.19 0.06 767 49.91 <0.01 0.05 Process Pre-Sterilised Non-Sterilised Neutral Theory   NICE, BUT YOU NEED A LEGEND FOR YOUR TABLE Lorenz Curve Contrast results (comparing the effects of water (A,B, C) based on permutational ANOVA of Gini Coefficient data Glossary: Community Evenness is a measure of the equality or distribution of individuals among species

Neutral theory predicts... There will be fewer differences in community composition between the Pre-Sterilised microcosms and the rain water samples than between the Non-Sterilised microcosms and rain water. 12h 167 h Pre-Sterilised Non-Sterilised A B C 45 Relative abundance of taxon (percent of total community) Taxon (ARISA peak) PS +NS Process Pre Sterilised Non Sterilised Neutral Theory  

Neutral Model... Makes predictions using only three parameters: J (total community size), m (which describes the fraction of recruits coming into the local community from the source pool), Ɵ (the fundamental biodiversity number).

Neutral theory predicts... That m will increase with increased immigration times. Process Pre-Sterilised Non-Sterilised Neutral Theory   Generated using Etienne, 2005.

Conclusions….. Both neutral processes and species sorting appear to be important during the colonisation of aquatic environments. However, species sorting seems more important in previously colonised environments! Variable Process Non-Sterilised Pre-Sterilised Structure (Bray-Curtis) Neutral Theory  Evenness  Composition neutral parameter m IF YOU CAN THINK OF AN END STATEMNENT THAT WOULD BE GOOD. SOMETHING ALONG THE LINES OF, THESE RESULTS ARE IMPORTANT BECAUSE….. OR MAYBE YOU COULD PRESENT THIS IN THE CONTEXT OF AUSTRALIAN BACTERIAL IMMIGRATION – DON’T WORRY ABOUT THESE AUSSIE IMMIGRANTS TOO MUCH… THEY HAVE ONLY A SMALL EFFECT BECAUSE WE HAVE A RESIDENT POPULATION OF KIWI BACTERIA WHICH ARE KEEN TO HOLD THEIR GROUND!!

Bacterial airborne immigration. ....

Thank you. Any Questions?