The ecology tag has no wiki summary.
3
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1answer
59 views
Are the posteriors “different”? How does one discuss the result?
First, I realize this may be a basic question. However, when I search the web for references on this issue, I run into the problem of wondering if the description I'm reading is applicable to the ...
0
votes
0answers
21 views
Fisher's exact test for comparing 2 years of population data?
I am a young ecology graduate student who is starting to learn statistics. I've already collected some data on our study populations that my adviser has asked me to analyze.
There are 20+ populations ...
3
votes
0answers
90 views
How to compare species communities between two years?
I would like to compare the data of a community of species between two years. I used to compare communities based on different levels of a factor (for example, a treatment). The case of a treatment is ...
1
vote
1answer
88 views
What does “return rate” mean in population ecology models?
What does "return rate" (tasa de retorno in spanish) mean in population ecology models? In context of capture-mark-recapture models. I have found many articles on ...
4
votes
0answers
59 views
Regressing on many outcomes in a spatial model
I'm measuring many microbe populations in a 'river model' ecosystem by sampling at two points. I want to test the hypothesis that key species upstream are the best predictors for any given population ...
4
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0answers
41 views
Help with designing the analysis of a radio telemetry study
I was wondering if there are any spatial ecologists out there who can provide some insight on the trouble I'm having with my Masters research.
I am looking at the association a bat species to high ...
3
votes
1answer
339 views
Initialize ARIMA simulations with different time-series
I have a fairly long time-series of annual abundances ($N_t$) of a wildlife species (73 years of abundances). To forecast the population’s trajectory, I have used ARIMA modeling. Examination of the ...
4
votes
4answers
206 views
Books about model selection in ecology
I am an ecology student and have to deal with 10 or 20 field variables, including species frequencies. I need to screen out what variables are most important in the occurrence of a bird species. What ...
5
votes
1answer
325 views
Custom power analysis in R
Distance sampling is a common technique used to estimate the abundance of wildlife species (such as deer or turkey). This technique employees line-transect based sampling where perpendicular distance ...
3
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1answer
359 views
Ecological mixed data cluster analysis: Transformations required? Use K-means or hierarchical methods?
I am trying to identify habitat types from 85 plots. I intend to do a cluster analysis to identify habitat types, and hope to fit additional plots into the identified clusters.
(For context, I took ...
7
votes
1answer
150 views
Does using box-cox transformation on individual data sets prevent these data from being comparable?
I have been using the box-cox transformation to normalise data for input to an Ecological Niche Factor Analysis software, as recommended by the software creators.
However, it has occurred to me that ...
2
votes
1answer
190 views
Is it possible to use common principal components for assessing covariance matrix similarity in R?
Is it possible to use common principal components for assessing covariance matrix similarity in R?
This approach was championed by Flurry, 1988 but this paper is what I have in mind.
References
...
5
votes
1answer
61 views
Estimating species distribution and rate of expansion using only positive data
Short version: is there any statistical method that can be used to develop estimates of abundance, spatial distribution, and/or rate of spread of a species when my dataset only includes presence data ...
3
votes
0answers
89 views
Comparing two non-linear biological models: differences in y vs. differences in slope
I'm an ecology PhD student, but unfortunately not a very mathematically sophisticated one. I am interested in ways to compare two non-linear models. I was really impressed with this answer, which ...
9
votes
2answers
199 views
What is the distribution of the error around logistic growth data?
In ecology, we often use the logistic growth equation:
$$ N_t = \frac{ K N_0 e^{rt} }{K + N_0 e^{rt-1}} $$
or
$$ N_t = \frac{ K N_0}{N_0 + (K -N_0)e^{-rt}} $$
where $K$ is the carrying capacity ...
13
votes
2answers
515 views
Question about logistic regression
I want to run a binary logistic regression to model the presence or absence of conflict (dependent variable) from a set of independent variables over a 10 year period (1997-2006), with each year ...
2
votes
1answer
215 views
Type of input data (proportions or log-ratios) for compositional analysis
I am comparing tree species use vs. availability within bird territories. I am using the R compana() function which uses Aebischer et al. (1993) method (package ...
5
votes
1answer
248 views
Species Richness, Dominance and Diversity Differences
I have collected 70 organisms from 4 different sites; two sites of treatment 1 and two sites of treatment 2. I also have a continuous explanatory variable (average temperature) which is different ...
