“Daddy, why do flowers smell nice? Why do ladybugs have spots?” From the time we can talk, we pepper our parents with “why” questions.

Answers satisfy a deep human need to make sense of the world. Darwin’s theory of evolution helps us explore those questions by showing how features such as flower fragrances and ladybug spots can help organisms survive and reproduce.

Many readers may have probably been asking another wonderful “why” question this summer and autumn: why are trees this year laden with so many seeds, cones, nuts and fruits?

Across the Kawarthas, numerous deciduous and coniferous species are carrying prodigious amounts of this “mast”. White cedar, white spruce, white pine and sugar maple are particularly striking. Eastern hemlock, red oaks, bitternut hickory and ironwood aren’t far behind.

The science of masting

Masting is the production of highly variable, synchronized seed crops by perennial plants. In mast (bumper) years, many individuals of the same species produce enormous quantities; in lean years, production falls dramatically. Acorns, beechnuts and conifer seeds are familiar examples.

Why reproduce in such extravagant bursts? One advantage is that seed consumers cannot eat everything. Another is improved pollination: when many wind-pollinated trees release pollen together, more can reach receptive female flowers — or, in conifers, the young seed cones.

Trees across the Kawarthas can produce seeds at the same time by responding to the same weather conditions. But masting follows no fixed schedule. Weather, previous seed crops and the energy and nutrients trees can draw on all interact. Ecologists understand much of this process but cannot yet fully explain why different species sometimes produce bumper crops together.

Oaks: A case in point

Everyone is familiar with the curious, tam-o’-shantered acorns that fall from oaks each autumn. Each contains a generous food reserve to support the young tree’s first roots and........

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