2023年美赛特等奖论文-A-2309229-解密.pdf

out for lack of water, while others can recover after drought. To explore this phenomenon,

we develop GIID model to describe the response of communities to drought and analyse

species, we set the environmental capacity of them as a function of soil moisture. Finally, we

modeled the soil moisture variation to describe the interaction between plants and the en-

vironment. We consider the water absorption by plants, irregular rainfall, and other factors.

We summarize these analysis and devise our GIID model. Then, we verify the correctness of

model. The results are shown in Figure 7.

more stable in drought. To quantify how the community benefits from the species diversity,

we calculate total biomass, coefficient of variation of total biomass, and S-W index to evaluate

the vigor, stability, and evenness of the ecosystem respectively. The experimental results

show that as the number of species increases, the total biomass of the community increases

large, the community would not benefit.

results show that: when droughts become stronger and more frequent, the complementary

effect among species also becomes stronger. And the biomass of the community increases

as the number of species increases. When droughts are less frequent, the competition among

species is stronger, and the increase in the number of species lead to decrease in total biomass.

The increase in the number of species always enhances community stability.

tion to the decrease in environmental capacity. So we set up a step function to simulate this

process. We find that habitat loss and environmental pollution will lead to decrease in total

discuss how to improve it.

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1 Introduction 3

4 Task 2 and 3 : Effect of Species Diversity 12

5 Task 4,5 and 6 : Impacts of Environmental Change on Species 18

6 Sensitivity Analysis 22

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1.1 Problem Background

the world because of the global warming. Drought is one of the extreme weather events that

will have a huge impact on our lives. The image shown below is collected from the U.S.

drought monitoring website Drought. gov. It reflects the drought conditions in the U.S. be-

tween 8 Feb. 2023 and 14 Feb. 2023.

Figure 1: Distribution of drought in the United States

Source :

drought.

1.2 Restatement of the Problem

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1.3 Literature Review

ods to simulate plant communities and the corresponding ecological principals. According

to the literature [1, 2, 3, 4], for the simulation, there are mainly three methods and for the

principles, there are mainly two principles we need to use. As the following figure shows:

1.4 Our Work

2 Model Preparation

2.1 Assumptions and Justifications

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