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Credit: US Forest Service
This sycamore, growing near Myersville, displays the effects of anthracnose disease. The fungus inhibits leaf elongation by attacking young leaves as they develop.
Many sycamores are displaying signs of anthracnose disease this spring. Anthracnose is much more prevalent during times of cool, wet conditions. The anthracnose fungus can inhibit leaf elongation by attacking young leaves as they develop. The leaves are curled up and often have brown blotches along the midrib.
Sycamore trees eventually grow out of this damage once the mean daily temperature rises above 65 degrees. Continued anthracnose infestations may result in the development of large cankers along the main trunk or clusters of dead twigs, giving the branches a "witches broom" appearance.
The quick-growing sycamore rarely dies from anthracnose because they can outgrow the damage, but sometimes a small or weakened tree can succumb.
In all likelihood there will be a number of plant diseases showing up this year due to the cold, rainy weather we experienced.
Soil compaction affects root health
Most terrestrial plants are highly dependent on the soil for their welfare. The tree roots in soil collect water, nutrients and secure the tree to the ground. A very favorable soil contains 50 percent open "pore" space, 45 percent minerals, and 5 percent organic material. The pore spaces in the soil are important to store water, air and other gases, and to provide open spaces for root growth and development.
A condition that dramatically affects the productivity of the soils is when it loses some of its pore space from compaction. Soil compaction occurs when heavy objects run over the soil and compress it to the point that pore spaces are reduced. Repeated compression results in a compacted soil with very small pore spaces.
Some of the more common compaction occurs with heavy equipment, large animals, people and heavy watering. This loss of pore space limits root penetration so that trees have superficial roots or an abundance of surface roots. The hard surface also inhibits water absorption, so much more runoff occurs and the soil is less able to retain water.
Soil compaction affects aeration and the reduced air flow affects root growth, causes buildup of toxic substances and results in higher soil temperatures, which can destroy tree roots and other microscopic and macroscopic plants and animals.
If soil compaction is so damaging, how can it be prevented or repaired?
Limiting access to the forest and landscape is the best preventive measure. Using mulch around trees or designating walkways is another good idea.
Ways to correct compacted soils include tillage, incorporating organic matter into the soil, cultivating plants and flowers, encouraging earthworms with mulch and organic material, and fertilizing trees.
Article by FCFCDB
Nature Notes for 5/29/2011
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