In a study of tree dispersion in a forest, we divided the forest into 1 sq km grid cells, choose 50 of them at random, and counted the number of trees in each cell. The means to variance ratio of the counts of trees per cell was much less than 1. What does this tell us about the spatial distribution of the trees?

#Question id: 9240

#Unit 9. Diversity of Life Forms

Use the following figure to answer the question.

Looking at the figure, what can you conclude about the data?

#Question id: 9241

#Unit 9. Diversity of Life Forms

The main goal of sustainable development is to ________.

#Question id: 9242

#Unit 9. Diversity of Life Forms

Eutrophication is often caused by excess limiting-nutrient runoff from agricultural fields into aquatic ecosystems. This process results in massive algal blooms that eventually die and decompose, ultimately depleting the dissolved oxygen, killing large numbers of fish and other aquatic organisms. Predict which of the following human actions would best address the problem of eutrophication near agricultural areas?

#Question id: 9243

#Unit 9. Diversity of Life Forms

Elevated carbon dioxide levels have been shown to contribute to the greenhouse effect, resulting in an increase in mean global temperature. Ecosystems where the largest warming has already occurred include snow-covered northern coniferous forests, tundra, and arctic sea ice habitats. Which statement best explains how the elimination of ice-covered ecosystems affects the rise or fall in global temperature?

#Question id: 9244

#Unit 9. Diversity of Life Forms

One characteristic that distinguishes a population in an extinction vortex from most other populations is that

#Question id: 9245

#Unit 9. Diversity of Life Forms

One characteristic that distinguishes a population in an extinction vortex from most other populations is that