The flat reclaimed areas consist of fertile organic soil, ideal for growing market garden crops such as onions, leafy greens, celery and carrots. Organic matter consists of living plant tissues and organisms found in soil. Organic matter improves the physical condition of soil, and residues from its decomposition play an important role in holding plant nutrients and water. Organic matter in soil undergoes change as it breaks down and decomposes and new material is added. Careful management of this soil is necessary to prevent wind erosion. Much of the fertile, organic soil has been depleted due to unsustainable use by farmers over the years. Submerged decayed trees contribute highly to the valuable fibrous nature of the soil, but without human assistance and ingenuity, the area would have little fertility.