ecology

Hi everyone, I'm working with a dependent variable which is the number of individuals of an species. The way in which we counted the individuals is along transects, so we have number of individuals in at least 7 plots at different distance from a plantation (from 0-20 m, 20-40 m, 40-60 m, etc)...

I have an experiment to look at habitat preferences of beetles and the effect of competition. In the first test, a beetle is on his own in an arena and I measured the % of time he spends in each of THREE types of habitat (open, bush and underground). I repeat this experiment with several...

Hi Guys, Hope you all are doing well. I am very new to statistics and I have a little doubt regarding what test to use to analyze my data. I have some bacterial population counts (4 bacterial species) for 4 different geographical sites. I wish to see the association between bacterial prevalence...

I have 2 batches of tree species and abundance data collected for a city. The difference between them is the sampling strategy - one was random unstratified, and the other was stratified and clustered. At a glance the species mixes and relative abundances are fairly similar but i want to test...

Greetings! I'm currently trying to investigate the impact of an event on the bird community of a National Park on my country. For that I have collected data in the BACI format (Before After Control Impact) and I would like to know what is the best way to analyze it. I have richness and...

Good morning, I'm struggling to fit a satisfactory model to a data set I have resulting from a systematic review. I performed a systematic review of estimated $ valuations of grasslands and the services they provide. All grasslands provide all services, but some studies only value one of...

Hi all, This question is in regards to options for analysing a dataset. I have a dataset where we have 23 video clips that have been treated using three different algorithms to change how each clips looks. Each treatment has then been viewed by a number of scientists to try and identify the...

Hi everybody, I would like to know how to statistically compare different "intrinsic growth rates", most of the times named "r", belonging to different populations. It's a ecotoxicological experiment with these two simple variables: 1) time (days, from 0 to 21) 2) live offspring (total...

Hi there! I am currently working on the analysis of a two part experiment looking at bacterial communities in diatoms, under different temperatures. It is quite a complicated one, and I was hoping I could get some input on how to analyze it. First, however, let me explain how it was...

Hi I am trying to create a raster stack of several ASCII files for an environmental variable. This is what I have done so far: >files <- list.files(path=paste(system.file(package="dismo"), '/temperature', sep=''), pattern='asc', full.names=TRUE ) >files #gives me a list of the files...

I have run general linear model (ANOVA) in SPSS to test whether habitat type (2 categories) and habitat disturbance (2 categories) have an effect on the size of deer groups. When I use the data for ALL groups (including mixed sex groups, all male groups and all female groups - they're all under...

Sorry if this has been asked before, if it has I couldn't find it. Also excuse me if I mix up terms, I'm a bit of a novice. My experiment had two categorical independent variables. 1.)The feeding history of the fly (protein fed or sugar fed) 2.)The type of substrate tested for preference...

Hi. I am trying to analyze data I have on bird migration and am stuck on what I need to do. Basically, I have the maximum abundance of birds seen per week for 10 weeks for 4 sites within a location, for 5 different species, and over the course of 5 years. So for one year, the abundance...

While helping Bugman and gianmarco with respective problems I became interested in the work they do. I love visualization and I love geographical plotting. But I'm in a field (literacy) that really isn't about geo-spatial representation of data. But then I had a though. I remembered seeing...

Hi everybody, I need to analyze possible differences in the invertebrates populations living in 3 different environmental treatments (3 plus 3 replica). A subsample containing invertebrates species is taken every week for a total of 10 sampling events. Therefore 10 invertebrates populations...

Hello, and thank you for reading. I am trying to test for what environmental variables (3 continuous distance variables e.g. distance from nearest village) influence 1) species richness at the site level (continuous variable) and 2) community composition at the site level (coordinates of...

Hello and thanks for taking the time to read this. Data structure: I have two datasets from two protected areas that differ in protection status. Both areas contain 43 and 37 sites each. Question: I would like to know which test would be the best for testing whether the PA status has...

Hi all, new user here hoping to become part of the community, I have recently purchased a book reccommended to me - Discovering statistics using SPSS (Field, 2013) with a view to knuckling down on statistical analysis of my data that i have collected for a Master's project. I have various...

I am trying to assess the fine-scale spatial distribution of tadpoles along a depth gradient in relation to abiotic and biotic factors -- and am having great difficulty in determining the best statistical test (Chi square VS ANOVA) to use BECAUSE I cannot determine what kind of data I have...

Hi All, I sampled crickets weekly over 5 weeks from the same population, and measured their body size. Half of the crickets were taken from predator's nests (sampled within a day of being caught), and half were sampled directly from their natural habitat. My research question is: are predators...