BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Vitis aestivalis | Summer Grape 



GENERAL BOTANICAL CHARACTERISTICS : 
Summer grape is a native, deciduous, woody, high climbing vine
[10,11,18].  It climbs by tendrils to about 33 feet (10 m), or sprawls
over low bushes and trees [22].  The stem diameter is usually about 1
inch (2.5 cm) but may be as much as 9 inches (22.9 cm), with ages
approaching 100 years [26].  The fruit is a berry 0.2 to 0.5 inches
(0.5-1.2 cm) in diameter [18].  The roots are large and hard [29].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Summer grape regenerates by vegetative reproduction and by seed.
Sprouts originate from vegetative buds both above and below ground.
Sprouts may grow 5 to 15 feet (1.5-4.6 m) in the first growing season.
Sprouts survive only 3 years under a closed-canopy forest.  Summer grape
also reproduces by layering [25,26].

Summer grape produces seed 3 years after establishment.  Good crops
occur most years in those vines with access to full sunlight [3,4,20].
Summer grape vines that do not receive full sunlight may flower but
usually do not bear grape clusters [3,4].  On fertile sites in North
Carolina, cluster-bearing summer grape vines averaged 1.2 ounces
oven-dry weight fruit per vine (37.1 g/vine) excluding fruit lost to
disease and insect predation [4].  Seed is disseminated by wind and
animals [20].

Summer grape fruit production is reduced by black rot fungus (Guignardia
bidwelldii) and curculio beetle (Craponius inaequalis).  In years of
heavy black rot fungus attack, seeds may only be 50 percent viable [20].
In a 2-year study of a North Carolina mixed hardwood forest, 37 percent
of the summer grape berries were infected by black rot and 57 percent
were damaged by curculio beetles [4].

Summer grape seeds accumulate in the seedbank and germinate only when
light and temperature conditions are favorable.  In a West Virginia
study, the germination rate averaged 19 percent after 11 years of soil
storage [32]. 

Seedlings grow much more slowly than sprouts and the tops are usually
winter-killed after the first growing season.  In West Virginia seedling
height after two growing seasons averaged 0.51 feet (0.16 m) [26].



SITE CHARACTERISTICS : 
Summer grape grows on fertile, well-drained, upland sites with abundant
soil moisture.  It grows on bench areas, coves, and southeast-facing
slopes of ravines where organic matter has accumulated [20]. In North
Carolina, summer grape is abundant on slightly rocky, steep sites with
an east-southeasterly aspect and below 4,230 feet (1,290 m) elevation
[4].  Summer grape occasionally occurs on floodplains or lowlands
[11,17], including hydric hammocks of Florida [30].

Summer grape grows on a wide variety of soil types including sand, clay,
and loam but is most abundant on light, nutrient-rich soils [21,24,26,
29].  In Mississippi, summer grape grows in the poorly drained clay soil
of bottomland hardwood forests [8].


SUCCESSIONAL STATUS : 
Facultative Seral Species

Summer grape is intolerant of shade.  It persists in closed forests only
if it is present in the upper canopy.  Under closed canopies, summer
grape seedlings are seldom present and vegetative sprouts die within 3
years [26].  


SEASONAL DEVELOPMENT : 
In North Carolina, summer grape flowers emerge with leaves in mid-April.
Leaves are fully grown by the end of May.  Flowers bloom and pollination
occurs the first 2 weeks of June, and fruit sets by late June [4].  In
the southern Appalachian region, fruit ripens in early fall, with large
clusters falling by mid-November [4,20,24].

Related categories for Species: Vitis aestivalis | Summer Grape