Final answer:
Species diversity encompasses genetic diversity within species and the diversity of the species themselves. Large single-crop fields are vulnerable to disease due to the lack of crop diversity, as seen in historical events like the Irish potato famine. Maintaining genetic diversity is critical for disease resistance and food security, with initiatives like the Svalbard Global Seed Vault playing a crucial role.
Step-by-step explanation:
Two components of species diversity are genetic diversity within species and the diversity of species themselves. Genetic diversity allows species to adapt to local conditions and contributes to the overall resilience of an ecosystem. The diversity of species adds to the complexity of ecosystems, where different organisms fill various ecological niches.
Large fields of a single crop are vulnerable to devastating diseases because they lack crop biodiversity. A single disease can spread rapidly in a monoculture where all plants are genetically similar, leading to catastrophic crop failures.
This was exemplified by the Irish potato famine where reliance on one potato variety caused a famine due to the crop being wiped out by a blight. Disease resistance is a key benefit of maintaining diversity among crops. Seed companies play a role in either supporting or reducing this biodiversity depending on their breeding and selling practices.
To prevent the loss of crop diversity, organizations such as the Svalbard Global Seed Vault preserve seeds from various crop varieties, providing a backup to maintain genetic diversity for future crop improvement and ensuring food security for human populations.