Trees are critically important in the food cycles of many insects, birds and mammals, including humans. The majority of our food crops depend on pollinators for fertilization. And the numbers of pollinators are in serious decline.
Pollinators include Butterflies and Moths (lepidoptera family) as well as Bees, Wasps,Beetles and Flies.
Please remember that dead wood is also critical for pollinators. Approximately 30% (around 1,200 species) of Bee species in North America are wood nesters. Generally, these bees nest in abandoned beetle tunnels in logs, stumps and snags. Dead limbs, logs or snags should be preserved wherever possible (Xerces Society, Pollinator Conservation Strategy, 2009).
The information in the following table is taken from ‘Bringing Nature Home’ by Douglas W. Tallamy, and available at Guelph Public Library.
| Common Name | Plant Genus | No. of Species Supported |
| Oak
Willow Cherry, Plum Birch Poplar (cottonwood) Crabapple Maple Elm Pine Hickory Hawthorn Spruce Ash Basswood (Linden) Hazelnut Walnut (Butternut) Beech Chestnut |
Quercus
Salix Prunus Betula Populus Malus Acer Ulmus Pinus Carya Cratageus Picea Fraxinus Tilia Corylus Juglans Fagus Castanea |
517
456 448 413 368 311 285 213 203 200 159 156 150 150 131 130 126 125 |