Final answer:
Dispersal limitation is a process that affects the spread of species due to various barriers, leading to higher biodiversity in tropical forests by controlling seed dispersal and influencing species compositions.
Step-by-step explanation:
“Dispersal limitation” refers to the constraints on the spread of species due to various barriers or hindrances that prevent them from reaching all suitable habitats. In the context of tree diversity in tropical forests, dispersal limitation can lead to higher biodiversity due to several factors. Isolation of suitable habitats can prevent certain tree species from spreading to those areas, thus maintaining their localized populations. Moreover, because different tree species have various dispersal agents and methods, such as wind, animals, or water, a change in any of these dispersal mechanisms, such as due to overhunting or habitat fragmentation, can have a significant impact on seedling recruitment and the overall species composition in an area. Habitat fragmentation and hunting can disrupt seed dispersal processes. The reduction of large vertebrates that act as dispersers due to hunting pressure can decrease the dispersal of large-seeded plants, as their dispersal relies on these animals. This can result in higher diversity if there is less competition from those large-seeded plants, allowing species with different dispersal strategies to proliferate. Additionally, some tree species might become more abundant if their seeds are dispersed by means not affected by hunting, such as small frugivores or abiotic factors like wind or water.