two-way-PERMANOVA and ordination diagram

#1
Hi
So I'm studying biology and took a statistics class this year. We got a homework were the Professor gave us an excel file (attatched) and 5 tasks we have to do with it. I already did 4 of them but I'm stuck at this one:

"4) Does Lepidopteran species composition in these data reveal signatures of land-use and sampling year? Perform an appropriate statistical test and illustrate your findings using an ordination diagram. Do sampling date and/or nectar flower abundance have any explanatory power?"

Some explanation for the data sheet: In the data sheet “Illmitz Lepidoptera species in columns” you find the numbers of butterfly sightings obtained during student courses, each of 1 week duration in early summer, over the years 2014-2018. The overarching scientific question of that field course was whether biodiversity in grassland (here: of Lepidoptera) differs between 3 land-use options (meadow, pasture, or fallow). The first two figures in the name of each sample denote the year. H = pastures; B = fallows; W = meadows. Further included are two columns “sampling day” (which is the calendar day of observations within each year to account for earlier or later timing of surveys), and “nectar flower abundance” (z-transformed; these data scale with the estimated availability of nectar resources per site during the surveys). In a second sheet you will find the analogous data, but in transposed manner: “Illmitz Lepidoptera species in rows”.

Oh and also we should use the program past3.

I tried sqrt-transforming the data (because of the highly different abundances) and then doing a two-way PERMANOVA with the year and land-use type definded as group. But I'm unsure if that's what he meant? If not, which test should I use? I know that for the ordination diagram I'm supposed to use NMDS plot. And for the last part I'm not sure how to do that.

Would be great if any of you have any tips :)
elly

PS: sorry if there are any mistakes but english isn't my native language :) But i have to do the tasks in english so I guessed it would be best to ask in english ;)
 

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