Juniper trees are invasive in the American west. They soak up large amounts of water and studies have shown that removing them improves the flow of ground water and allows for the native sage and grasses to grow better thereby improving habitat for native species.

Juniper wood (the core wood especially) is extremely resistant to weather and makes good fence posts. However, the wood is hard on saws and it doesn't hold a straight line well after cutting and is thereby not been harvested in mass. Finding a market for Juniper wood would then help to create jobs in many rural towns in the west where unemployment is high (I grew up in Prineville, Oregon, no shortage of Junipers, same could not be said for jobs) while also increasing habitat and the retention of water in the soil.

The Mongoose problem in Hawaii is more straightforward. They are an invasive species brought in to hunt invasive rodents, they failed to hunt rodents and instead have killed off a number of native species. Using gene editing to introduce a population that gives birth to only males or a sterile female population similar to how scientists have removed mosquitos would be a preferable fix to poison and traps (current model). That's not too much to ask right, just map the Mongoose genome :)