Targeting tree species within ecosystem restoration

Posted on June 4th 2021 by Sarah Pocock

Around half of the world’s forests have been lost or are degraded, resulting in loss of biodiversity and essential ecosystem services such as water regulation and food production. Ecosystem restoration can help to restore these vital elements, but it is important that we look at the how, not just the why, when we talk about restoration.

With 2021 representing the beginning of the UN Decade on Ecosystem Restoration, all eyes are focused on restoration as a means to transition towards a healthier planet, for people and nature. Their ecosystem restoration definition includes assisting the recovery of degraded or destroyed ecosystems, which can be achieved in many ways.

On one hand, governments and organisations around the world are committing to plant billions, or even trillions, of trees to restore forest ecosystems. At the other end of the scale, people are looking to natural regeneration and rewilding as an opportunity to let nature do the restoration with a little targeted assistance to give ecological processes a helping hand. A combination of approaches will be necessary in order to restore the world’s degraded forests, and the Global Trees Campaign (GTC) supports a range of methods, each suited to the local context, developed in partnership with local stakeholders and – crucially – focusing on the recovery of threatened tree species within these efforts.

Here, in celebration of World Environment Day, we delve into a few GTC projects, which emphasise the recovery of threatened tree species within wider ecosystem restoration initiatives.

Restoring threatened apples and pears in Central Asia’s fruit-and-nut forests

Central Asia is the origin of many of our familiar fruit and nut crops; apples, pears, apricots and walnuts all originate from the region’s ancient forests. These forests have experienced significant declines, however, leaving many of these crop wild relatives threatened with extinction. For more than a decade, GTC has supported fruit-and-nut forest restoration in Kyrgyzstan and Tajikistan, where important populations of these threatened trees are still found. Our work here takes a combined approach of reducing threats – mainly low regeneration due to livestock grazing and small, isolated populations resulting in poor fruit production – and boosting population numbers through targeted tree planting. We are now seeing some of these saplings mature into trees capable of producing fruit and seeds themselves, in particular the Critically Endangered Niedzwetzky’s apple, Malus niedzwetzkyana, while fencing around wild trees has enabled naturally regenerating seedlings to survive without grazing pressure. This is a crucial milestone and means that there is a greater chance of the species being able to regenerate and survive in the long term.

Monitoring Malus niedzwedskyana trees over a decade after planting. Credit: FFI

Conserving critically endangered magnolias in northern Vietnam

Magnolia grandis, a Critically Endangered tree with beautiful flowers and characteristic large leaves, has suffered declines due to logging, fuelwood collection and low wild seedling survival across its limited range. The world’s largest population of this threatened tree is found in the limestone hills of northern Vietnam and it is here that GTC has been working in partnership with local communities to safeguard the species. Since 2013, we have introduced monitoring, patrolling and reinforcement planting, and these efforts have been paying off. We have witnessed a decline in illegal logging of M. grandis, with zero incidences recorded since 2017, demonstrating how valuable the community ranger-led patrols have been in deterring illicit activity. Simultaneously, local cardamom farmers, who would previously weed out M. grandis seedlings growing in their plots, now willingly maintain them, indicating a shift in attitudes and behaviour towards this species. Encouragingly, surveys are now recording naturally growing seedlings within the forest, providing real hope for the long-term survival of this charismatic tree.

Magnolia grandis seedlings being cared for at the project nursery. Credit: Chu Xuan Canh/FFI

A keystone and flagship species for restoration in Chile

Nothofagus (southern beech) trees are keystone species, and play an integral role in the ecology and biodiversity of Southern Hemisphere forests. Nothofagus forests have been largely destroyed, the species exploited for their timber and replaced with exotic forestry plantations. These uniform, highly flammable plantations have led to unprecedented fires, exacerbated by hotter and dryer conditions brought about by climate change. In 2017, more than 580,000 hectares burned in central Chile, leaving remaining natural forests severely fragmented and threatening the survival of native Nothofagus flagship species. Our GTC partners, NGO Club del Arbol de Talca, based in Maule region and led by the Forestry Engineer Persy Gómez, are implementing a reinforcement programme for the endemic Endangered species, Nothofagus alessandrii. This project is engaging and working very closely with small landowners who live near the species’ distribution. These areas are badly degraded and the species’ populations are severely fragmented. Three in-situ trial plots have been established in private land, where exotic pines are being cleared, N. alessandrii seedlings are being planted, monitored and watered regularly, and bird boxes are being installed to attract native birds that control mice, which eat the seedlings.

Clearing non-native pines to make way for Nothofagus alessandrii seedlings. Credit: Club del Arbol de Talca

Restoring an African island in the sky

Mulanje cedar, Widdringtonia whytei, is Malawi’s national tree, found naturally only on Mount Mulanje. It is highly valued for its durable and fragrant timber, however illegal logging means it is now Critically Endangered. An increase in uncontrolled manmade fires also threatens the species, with fire used in hunting to flush game, charcoal production and to clear land for crops. If fire sweeps through young Mulanje cedar trees before they have established, population recruitment is drastically reduced. Mulanje Mountain Conservation Trust and the Forestry Research Institute of Malawi have supported eight community nurseries to be established around the mountain. Now, over 80 members have been taught to propagate Mulanje cedar seedlings, which are ready to plant back onto the mountain and provide income from seedling sales. Over 500,000 Mulanje cedar seedlings have been planted onto the mountain since 2016, funded by the Darwin Initiative and WeForest. In 2021, planting efforts also included other species, like Podocarpus milanjianus, which loggers have started to target. Investigations are also underway to improve survival and growth rates of planted trees, particularly looking at companion species planting that may influence a positive soil microbiome community for Mulanje cedars.

MMCT, FRIM and BGCI staff with planted Mulanje cedar trees. Credit: Mulanje Mountain Conservation Trust

Well-planned and implemented restoration is a vital part of our conservation toolkit, but it is important to follow best practice, such as that outlined in the “10 Golden Rules of Tree Planting” to ensure the best possible outcomes for biodiversity, people and planet.

This article was co-authored by Alex Hudson, Noelia Alvarez and Sarah Pocock.