Dead trees are much more than fallen trunks. They are shelter, food, and living space for many species that would otherwise struggle to find a place to live, especially in urbanized environments. At Marimurtra we have a good example: the large Aleppo pine (Pinus halepensis) that, damaged by a windstorm a few years ago, ended up dying, but still stands upright within the Garden.
Instead of removing it, it was transformed into a Land Art sculpture thanks to the Blanes-based artist Miquel Gelabert. Today, this piece is not only an artistic element within the Garden’s landscape, but it has also become a valuable refuge for biodiversity.
A new inhabitant in the Garden: the green woodpecker
This past winter and spring we had an extraordinary surprise: although the green woodpecker (Picus sharpei) had occasionally been seen at Marimurtra in previous years, until now it had never been observed nesting there. This year, for the first time, it chose the dead pine to excavate a cavity and successfully raise two chicks.
This event confirms how the presence of dead wood can benefit forest species that are hard to spot in humanized environments. The green woodpecker is a protected species and considered a bioindicator: its presence indicates a healthy and balanced environment. Its nesting at Marimurtra is, therefore, wonderful news for the Garden’s biodiversity.
Natural allies against pests
Woodpeckers are more than beautiful and curious birds: they are excellent controllers of forest pests. With their strong beak and long, sticky tongue, they can capture insects hidden under the bark or inside the wood.
Some pests the green woodpecker can help control:
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Pine processionary (Thaumetopoea pityocampa): preys on early larval stages and pupae.
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Pine bark beetle (Tomicus destruens).
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House longhorn beetle (Hylotrupes bajulus): eats both larvae and adults.
More fauna that benefits from dead wood
At Marimurtra, several deadwood elements are deliberately preserved as natural habitats. Many other species make use of these spaces to live and, in doing so, contribute to maintaining the Garden’s ecological balance.
Insectivorous birds:
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Great tit (Parus major): nests in dead trunk cavities and feeds on caterpillars, butterflies and other insects.
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Blue tit (Cyanistes caeruleus): also uses holes in dead wood and hunts larvae and aphids.
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Short-toed treecreeper (Certhia brachydactyla): searches for small insects under tree bark.
Other species such as the grey long-eared bat (Plecotus austriacus) or those from the genus Myotis (like the dark-nosed bat) may use crevices in old or dead trees to rest or breed. They are excellent hunters of mosquitoes, moths, and other flying insects.
Dead wood: bioindicator of healthy forests
The presence of dead wood —both trunks and fallen branches— is a key indicator of a forest’s maturity and health. Contrary to what it may seem, decomposing wood is a vital resource for hundreds of species.
Wood cavities serve as shelter for a wide variety of fauna such as birds, reptiles or mammals. Additionally, xylophagous insects, like beetles, feed and reproduce in this type of wood. This is a key element for the ecosystem, as they are the first link in a complex food chain.
This entire natural process is only possible thanks to the essential work of decomposers, such as fungi and bacteria. They are the silent protagonists: they release and recycle nutrients from dead wood, improve soil quality and contribute to forest regeneration.
Marimurtra, a living and evolving garden
At Marimurtra we understand green space management as a tool to enhance biodiversity. Leaving dead trees in place, as long as it is safe, is a simple and effective practice to promote wildlife, especially in urban environments where this type of habitat is scarce.
The nesting of the green woodpecker is proof of this. And it may just be the beginning.
