Establishment of Native Aquatic Plants for Fish Habitat: Test Plantings in Two North Texas Reservoirs

ABSTRACT

Test plantings of native aquatic plant species were made in two Texas reservoirs. Founder populations of three native submersed or floating-leaved species were established within small (2- × 2-m) exclosures utilizing actively growing transplants. Herbivory and excessive sedimentation proved to be deterrents to plant survival and expansion. Nine small founder populations of Vallisneria americana were established within North Lake, a small reservoir with limited water level fluctuations and a developing community of native pioneer aquatic plants. Plants within all nine exclosures successfully established and began vegetative growth. In intact exclosures, the plants rapidly covered the sediment surface within the exclosures. Expansion beyond the exclosures was variable and occurred primarily during the cooler portions of the year when herbivory was assumed to be low. During the spring of the second growing season, herbivores cropped most of the previous expansion leaving only a narrow fringe of plants surrounding the exclosures. At Lewisville Lake, a large, turbid reservoir with significant seasonal water level fluctuations and no existing aquatic macrophytes, two native pioneer species (Potamogeton nodosus and Heteranthera dubia) were planted within exclosures. Good survival and growth occurred within undamaged exclosures, although no expansion ever occurred outside the fenced areas. Plantings of H. dubia in undamaged exclosures also showed excellent survival except for those planted in areas subject to very high turbidity and sedimentation rates. Again, herbivory prevented any expansion outside the protective exclosures.

Key Words:

• native macrophytes
• Vallisneria americana
• Heteranthera dubia
• Potamogeton nodosus
• plant establishment
• restoration