GENE MULLER and ERIC OLSEN

The arrival of autumn is told by trees. With the advance of shorter days and cooler temperatures, chlorophyll abandons leaves, turning trees lovely shades of orange, red and yellow.

For many people, this splashy transition of color conjures other events — football, apples, Halloween. But to those who love beer, those golden amber hues represent something else: Oktoberfest. And perhaps that association is fitting, not only because Oktoberfest originated from Germany’s Black Forest, but because without forests there would be no beer.

Beer’s main ingredient is water (up to 95 percent). And what plays a huge part in the quality and quantity of water from our rivers, streams and aquifers? That’s right — trees.

Forests achieve this massive water benefit by storing and filtering rain and snow. They capture rainfall and shade streams, lakes and snow from evaporation; the forest floor filters runoff; and tree roots keeps soil together so it can hold water like a sponge.

For brewers, keeping a mindful eye on the health of our trees is smart business. That’s why more than two dozen breweries around the country, including my own here in New Jersey, are participating in OktoberForest to celebrate the connections between forests and beer.

The Flying Fish facility is located just few miles from our main water source, the Delaware River. But the quality of the Delaware’s water is reliant on forests way upstream in northwestern New Jersey, Pennsylvania and New York state. It’s all interdependent. Healthy forests mean better water, and that is definitely key for a brewer like me.

In New Jersey, our forests face challenges like fragmentation — when habitat is lost or becomes disconnected because of development — as well as browsing deer and invasive insects. For our Pine Barrens, the specter of an uncontrolled fire always looms. And these threats are made worse by climate change.

The good news is that organizations like The Nature Conservancy are working to protect and restore critical forests in New Jersey. They have helped conserve more than 55,000 of acres of land and forest across the state. They are working to create an uninterrupted greenway from the Highlands to the Kittatinny Ridge to safeguard water resources and provide habitat for bobcats, which are endangered here. And they are actively restoring the lands around the Paulins Kill, the third largest Delaware River tributary in New Jersey, with a goal of planting 50,000 trees in the watershed by 2020.

In New Jersey, we are fortunate to be home to more than 60 craft breweries, and that number keeps growing. Those breweries produce about 80,000 barrels of beer each year (that’s 2.5 million gallons!), and every single one of them is dependent on a natural water source.

Many of these breweries are already operating smar, and increasing sustainable practices that stretch and renew the resources we use to brew beer. At Flying Fish, our facility is a showcase for recycling, reuse and conservation, including passive lighting, solar electric, high-efficiency kettles and equipment, grain recycled as livestock feed, and even a rain garden outside our office that helps protect nearby Cooper Creek from pollution and erosion.

But we all can do better by our beer, and the forests that provide its main ingredient, by helping to raise awareness of the important role forests have in our lives.

The first Oktoberfest celebrated a marriage; please join us this month as we celebrate the relationship between our forests and beer. You can help us celebrate this marriage throughout October at Flying Fish, and online at www.OktoberForest.org.

Prost!

Gene Muller is the owner of Flying Fish Brewing Co. Eric Olsen is director of land conservation for The Nature Conservancy in New Jersey.