Increased tree cover poses a risk to grassland bird species

Increasing tree cover is generally considered good for protecting nature and combating climate change. However, new research suggests that the spread of trees in ever-open areas such as savannahs and grasslands can harm local animals, especially grassland-dwelling birds. A major study by Global Change Biology found that grassland birds have declined by more than 20% in African savannas.

Understanding Open Ecosystems

Grasslands and savannas are very important for biodiversity. They make up about 40% of the Earth’s landmass and support many different species of animals, from large plant-eating birds to wading birds. However, these ecosystems are under threat from conversion to farmland, construction and overgrazing. Another threat is timber encroachment.

Definition of timber encroachment

Timber encroachment occurs when open areas such as grasslands and savannas become overgrown with vegetation. This change makes the ecosystem more homogeneous, with less diversity of plants and animals. As a result, overall biodiversity decreases.

Factors promoting timber encroachment

Several things cause timber encroachment:

• Disturbance of understory systems: Natural and human activities such as fire suppression and pasture conversion allow the trees to grow further.
• Climate change: Higher CO2 levels help trees grow more than grass, causing grasslands to shrink.

Consequences for biodiversity

• The transition from open spaces to areas with more trees has major impacts on biodiversity:
• Decline in bird populations: Grassland inhabiting bird species are declining as trees take over their habitats.
• Changing ecosystem dynamics: Animals such as grassland rodents are threatened by soil changes and high risk of predation.

Invasive species and garden effects

Invasive tree species worsen timber encroachment. In India, for example, species such as Prosopis juliflora have converted grasslands into dense forests, causing further habitat loss. To combat the negative effects of timber encroachment, more research is needed to understand its effects and monitor open ecosystems over time. It is also important to stop the misclassification of these habitats as “waste land” to effectively conserve them.

Source

Current Affairs Quiz: 1 August 2024