How to Establish Forests on Coastal Saline-Alkali Land? Key Points for Windbreak Planting and Soil Improvement

Planting trees by the sea sounds romantic, but in reality it is a "tough battle." Strong winds, salt spray, and poor salinized soil mean many seedlings do not survive their first summer. In Taiwan, China, civil public welfare organizations and forestry research institutions have joined hands to repeatedly experiment and replant year by year on the salinized barren land along the western coast, aiming to build a "Green Great Wall" for the coast. This shelterbelt can block wind and salt spray, protecting the farmland and villages behind it. Today, let us use this topic to discuss the ins and outs of afforestation on coastal saline-alkali land.

Why is it hard for trees to grow on salinized barren land

Coastal afforestation is difficult because of three things: wind, salt, and poor soil. Sea winds blow year-round, accelerating water transpiration from seedlings and driving salt-laden moisture into the leaves, "pickling" the tender shoots and leaves; when soil salt content is high, roots struggle to absorb water, and seedlings easily suffer "physiological drought" - despite what looks like plenty of watering, the leaves still turn yellow and curl at the edges; in addition, much coastal land is sandy or gravelly, with poor water and fertilizer retention and low organic matter content, so seedlings are essentially struggling to survive in an environment that is short on water, short on nutrients, and harsh on top of that.

Improve the soil and choose the right trees before planting

First, choose the right tree species. Pick native species that are salt-tolerant, wind-resistant, and tolerant of poor soil, such as the commonly used Casuarina equisetifolia, Hibiscus tiliaceus, and Pongamia pinnata along the coast of southern China, and the common black pine, Chinese ash, and tamarisk along the northern coast; for specifics, consult the local forestry department. Second, improve the soil. Before planting, dig trenches to drain salt and raise the planting surface, and combine this with replacement soil and increased application of organic fertilizer to improve soil structure; covering the surface with chopped straw or weeds can reduce evaporation and inhibit the upward return of salt. Third, use large seedlings with soil balls for planting whenever possible; the survival rate is much higher than with bare-root small seedlings, and they are also more likely to make it through the first year.

Post-planting care determines success or failure

Afforestation timing should avoid periods of strong wind and drought, and be carried out around the rainy season. Dig holes large enough, and after planting water thoroughly once to settle the roots; at wind gaps, temporary windbreak nets or windbreak fences can be set up to give young seedlings a "protective umbrella." Where conditions allow, use drip irrigation, supplying water little by little and often, which both saves water and slowly pushes salt down out of the root zone. The first two or three years are the critical period for young forests: replenish water in time, replant missing trees, and prevent and control pests and diseases. Only when the shelterbelt closes into shape will its wind-blocking and soil-stabilizing effects truly appear.

In many places, support such as free provision of seedlings or afforestation subsidies is available for coastal shelterbelt construction; specific standards are subject to what the local forestry authorities publish. Coastal shelterbelts are the barrier for farmland and villages. Planting them is only the first step; only sustained management and protection can make this "Green Great Wall" stronger and stronger.