Habitat
Rich, dark, sandy loam soils of hardwood hammock slopes, ravines, and bluffs. Usually in steephead ravines (deep cuts made by erosion into coastal plain sediments). The ravines are much cooler and more moist than the land surface above and harbor remnants of the more temperate flora that existed in the region during the Tertiary ice ages. Uninterrupted seepage and a humid microclimate appear to be important characteristics of the habitat. Associated species include Magnolia grandiflora, Fagus grandifolia, Pinus glabra, and Ilex opaca (Ward 1979, Southeastern Wildlife Services Inc. 1982, Stalter and Dial 1984, USFWS 1986).
Ecology
Torreya trees do not reach reproductive maturity until they are 15-20 years old (USFWS 1986). Reproductive structures appear in March or April (USFWS 1986), and pollen is disseminated by wind (Baker 1985). Seeds mature in September to October of the second year following pollination and, when mature, are often gathered by squirrels (USFWS 1986). Seeds germinate in one to three years (usually two), following a period of warm and then cool temperatures (USFWS 1986).
Although many trees were cut for fence posts and other uses, the Torreya was still relatively abundant in the under- to mid-story of ravine woods and bluffs along the Apalachicola River early in this century (Reinsmith 1934, Kurz 1938). In the early 1960's, however, Godfrey and Kurz (1962) discovered that almost all large trees had died, apparently as a result of a fungal blight that produced lesions and necrosis of leaves and stems. At present, most (possibly all) of the trees in the wild are root sprouts that rarely survive to reproductive maturity; many or most cultivated trees are also infected (USFWS 1986). Alfieri et al. (1967) isolated a number of different fungi from infected trees, most of which are relatively common soil inhabitants. Many authorities believe that the fungal infections are merely symptoms of a decline precipitated by other factors such as increased sunlight or alteration of seepage patterns following logging of ravine woods and/or adjacent upland pine forests, repeated droughts, or a change in microclimate following construction of the Jim Woodruff dam in 1956 (Savage 1983, USFWS 1986). It has also been suggested that an introduced soil-borne pathogen, Phytophthora cinnamomi, might have played a part in the Torreya decline (USFWS 1986, Barnard 1987).