A sudden disease among essential primary producers will affect life through out because the primary producers is the main energy producers and sources in the ecosystem.
When a primary producers is infected by a disease,the primary consumers depend on primary producers for energy and feed directly on primary producers. When it's feed on it, the disease is transmitted to the primary consumer, the primary consumer transmit it to secondary consumer which feed on primary consumer and then to tertiary consumer which feed on the secondary consumer.
Therefore, the disease will affect all life in the ecosystem because each trophic level or organisms depend on primary producers for energy.
