For example, jack pine cones don't open up and release their seeds on their own until they're affected by high heat.
Literal
For-example jack pine [of-の] pinecones [topic-は], high-temperature [by-により] are-affected until [topic-は] by-themselves open seeds [object-を] release [don't-しない].
Another scientific-register sentence. ~までは~ない ('does not X until Y') is a temporal negation pattern. によって is the formal passive agent marker (more formal than plain に). 自ら ('by oneself, of one's own accord') is a reflexive. A statement about serotiny — a classic example in ecology.