And the moose go into rut, and then calves are born....

Bailey, R.C. 1982. The moose that I have known. Can.J.Zool. 67:101-112.

Beginning with a $100,000 inheritance that is input into the organic farm, one can estimate the cumulative farm net income (the stock) both annually and over a prolonged period based on the various expenses (outflow) which must be paid per year, and the sources of revenue (inflow) within the same time period.

Note: The values and variables used in this model were based on the University of California Agriculture and Natural Resources Guide, or the Sample Costs to Produce and Harvest Organic Strawberries Guide for the year 2024. 

Note: As this is an example of a simple system, the model includes one stock component, an inflow, and an outflow, each of which is affected by a variable. The stock within this model is the monkey population, the inflow is the monkey births, which are affected by the monkey birth rate, and the outflow is the monkey deaths, which are affected by the monkey death rate. Exponential and graph population data can be viewed using the "Simulate" feature. 

The model simulates the local environmental (specifically greenhouse gas emissions), economic, and resource impacts of transitioning from internal combustion engine vehicles (ICEVs) to electric vehicles (EVs) for personal ownership in New York City in the context of a sustainable program of new energy vehicles, which is the context of the current era. To be realistic, we combine delay and stochasticity in this model to simulate the real world. By understanding the model, one can gain insight into the importance of EV penetration for sustainable development.

This model analyzes the growth and dynamics of Oshawa’s population using a logistic approach. Starting with an initial population of 170,000 and an increased carrying capacity of 180,000, it evaluates how the addition of new neighbourhoods, planned to accommodate an extra 10,000 residents over the next 10-15 years (or whatever time period) affects population changes. Key factors include the Oshawa Residents Death/Emigration Rate of 0.8% (realistic percent approximation), accounting for natural deaths and emigration, and the Oshawa Residents Birth/Immigration Rate of 2.4% (also a realistic percent approximation), reflecting new residents through births and immigration. The model tracks the net population change, providing insights into how Oshawa's population might grow or stabilize as it approaches its new carrying capacity!

When a human population is at or near its carrying capacity, the birth rate equals the death rate. In this state, the population size remains stable because the number of individuals being born roughly matches the number of individuals dying. This equilibrium prevents the population from growing any further, as the available resources are just sufficient to maintain the current population size.

If the human population is below the carrying capacity, the birth rate tends to be greater than the death rate. This is often because there are more abundant resources per person, leading to better health, improved access to necessities, and increased life expectancy. In such conditions, population growth can occur, as more people are being born than are dying, pushing the population size upwards. 

Conversely, when the human population is above the carrying capacity, the death rate surpasses the birth rate. This can happen when resources become scarce, leading to issues such as malnutrition, lack of access to clean water or healthcare, and increased disease prevalence. As a result, the population may decrease until it returns to a level that can be sustained by the available resources.