Native pepperberry shortage

Last year, the many mountain pepperberry (Tasmannia lanceolata) bushes on our property produced very few berries. The few I saw were hardly worth picking. This year hasn't been much better. I was hoping for a bucket full of plump, tasty berries to flavour a science experiment we have underway in the dining room (pictured below). While there are more than last year, I've ended up with less than half a jar of dried pepperberries so far. Some of the pepperberry bushes on our property are very large and twice my height, and they are all growing strongly. There are male and female bushes, and they all look healthy. So I am not sure why the plants have produced so few berries. A few years ago there were so many, we couldn't pick them all. I am wondering if the chill factor has something to do with it. Last year's winter was very mild, but this year we've had three lots of snow already, and it's only the 2nd of June.  I will be interested to see what next year's crop will be like. Pepperberries are especially good for flavouring roasts and beef, and I've used them to replace pepper in other dishes too. I would describe them as peppercorns with a beautiful pink colour and more complex flavour.