The Vague Plan Vibes Summary

June 22, 2026

Overview

The basic idea of what I want to produce is an R package or a few functions that can be used to easily create plots of ecological models from real life data. Since this project is just for my own practice, I don't plan to host my package anywhere. This is mainly to get better at programming and to help my understanding of how math plays a role in ecology. Almost all of the models used in ecology do not fit real life perfectly, I do not intend to make a package that can be used widely but maybe a few things will become easier with some prewritten functions. It is also likely that someone has already done what I am hoping to accomplish, I'm okay with that as long as I learn something new.

I am starting small with only two models that will be used to create two functions. These functions will both output a plot based on data input. Ideally, someone can just plug in their cleaned data set columns to get an output but it is likely that I will have to write some preliminary functions. The two models I plan to start with are Lotka-Volterra and the R* rule which are both used for assessing competition between two species.

Lotka-Voltera Models

L-V models are used to predict population dynamics between two species with a shared resource, they can also be used to predict the outcome of predator-prey interactions. For now, I am focusing on competition between two species. The equation for the competitive model between two species looks like this:

I plan to go over my exact use of this model in more detail in later posts but essentially, I want to write a function that allows someone to plug in values for these different variables and get a plot of population over time in return.

R* Rule

The R* hypothesis is very similar to an L-V model except it looks only at the resource amount for each of the two species and ignores if a species interferes with its' ability to consume the resource. Below is the formula for this model.

My goals with this model are the exact same as for the Lotka-Volterra model except instead it will be population over resource availability.

Conclusion

Ok, that's it for now! I am hoping to have updates every week or at least every other week so come back soon!

Sources

Goals With Lotka-Volterra Models

July 5, 2026

After doing some pondering, I'm not sure if the R* rule can even be used for what I want to do...so I am starting with L-V models because they feel more concrete. I want to specifically create a function that plots the Gause-Witt isocline analysis of these models but I may move on to plotting other interpretations and uses later on. Below is a photo of the Gause-Witt isocline analysis from Mallet (2012).

Where N represents population size, r represents growth rate, and alpha represents the effect of the two species on one another. The function will have r, alpha and population sizes 1 and 2 input and return a Gause-Witt isocline. Ideally, users can simply plug in a large dataset full of population numbers over the years and then use multiple functions to calculate growth rate and alpha before creating the plots. Over the next week or so I want to determine which direction is best to work in and start getting something written in R.

Come back soon and feel free to email me with suggestions!

Sources