Hanging plant: [I]Carpobrotus edulis[/I]

[palermo]

I'm studying Carpobrotus edulis for a college project. It's an invasive species native to South Africa that is rapidly spreading across coastal cliff sites around Europe.

Carpobotus edulis

Here is a photo I took of the plant hanging down a cliffside. My question is regarding the brown "dead" part of the plant in the middle. Why is it brown? Is it because other layers of stems are covering it, blocking sunlight and thus not allowing photosynthesis? Or is it merely a dead appendage of the plant? If so, any reason why it died or did it just reach the end of it's lifespan?

I'd appreciate if anyone could clear this up, cheers.