A long-term study of tree seedling recruitment in southern Appalachian forests: the effects of canopy gaps and shrub understories

Canadian Journal of Forest Research - Tập 30 Số 10 - Trang 1617-1631 - 2000
Brian Beckage, James S. Clark, Barton D. Clinton, Bruce L. Haines

Tóm tắt

We examined the importance of intermediate-sized gaps and a dense shrub layer on tree seedling recruitment in a southern Appalachian deciduous forest. We created 12 canopy gaps under two contrasting understory conditions: 6 gaps were dominated by the dense, shade-producing shrub, Rhododendron maximum L., while the remaining gaps were relatively open. Density of first-year and >first-year seedlings was monitored for 5 years in transects extending from adjacent undisturbed forest through the experimental gaps. We concurrently measured the understory light environment, soil moisture, litter biomass, and seed rain. Neither species diversity nor richness consistently increased following gap formation. Acer rubrum L. responded consistently to canopy gaps with increased seedling densities while most other species, including both shade-tolerant and shade-intolerant species, did not. Seedling densities were especially low and unresponsive to gap formation in areas dominated by R. maximum. Understory light levels were consistently low beneath R. maximum and did not increase with canopy gap formation. Our results suggest that dense shrub cover can neutralize recruitment opportunities in canopy gaps, that seed rain often limits recruitment in gaps, and that canopy gaps that are larger or include understory disturbance are needed to maintain diversity in these forests.

Từ khóa


Tài liệu tham khảo

Baker T.T., 1998, For. Ecol. Manage., 109, 21, 10.1016/S0378-1127(98)00259-X

Barden L.S., 1979, Oecologia, 44, 141, 10.1007/BF00346412

Barden L.S., 1980, Oikos, 35, 16, 10.2307/3544722

Barden L.S., 1981, Oikos, 37, 205, 10.2307/3544466

Barden L.S., 1983, Castanea, 48, 19

Bonan G.B., 1989, Ecol. Modell., 45, 25, 10.1016/0304-3800(89)90076-8

Brewer R., 1978, Oikos, 30, 149, 10.2307/3543535

Brokaw N.V.L., 1989, Ecology, 70, 538, 10.2307/1940196

Busing R.T., 1994, Vegetatio, 115, 19, 10.1007/BF00119383

Busing R.T., 1997, Oikos, 78, 562, 10.2307/3545618

Canham C.D., 1988, Ecology, 69, 786, 10.2307/1941027

Canham C.D., 1990, Can. J. For. Res., 20, 620, 10.1139/x90-084

Carlton G.C., 1998, Ecol. Monogr., 68, 99, 10.1890/0012-9615(1998)068[0099:ROTSBS]2.0.CO;2

Chesson P.L., 1982, J. Math. Biol., 15, 1, 10.1007/BF00275786

Chesson P.L., 1981, Am. Nat., 117, 923, 10.1086/283778

Cho D., 1991, Vegetatio, 93, 9, 10.1007/BF00044920

Clark J.S., 1990, Biogeochemisty, 11, 1, 10.1007/BF00000849

Clark J.S., 1998, Ecol. Monogr., 68, 213, 10.1890/0012-9615(1998)068[0213:SASSOR]2.0.CO;2

Clebsch E.E.C., 1989, Ecology, 70, 728, 10.2307/1940223

Clinton B.D., 1993, Ecology, 74, 1551, 10.2307/1940082

Clinton B.D., 1994, Am. Midl. Nat., 132, 308, 10.2307/2426587

Collins B.S., 1987, Vegetatio, 70, 3, 10.1007/BF00040752

Comins H.N., 1985, Am. Nat., 126, 706, 10.1086/284448

Dahir S.E., 1996, Can. J. For. Res., 26, 1875, 10.1139/x26-212

Dalling J.W., 1998, J. Ecol., 86, 674, 10.1046/j.1365-2745.1998.00298.x

Della-Bianca L., 1985, South J. Appl. For., 9, 191, 10.1093/sjaf/9.3.191

Denslow J.S., 1990, Ecology, 71, 165, 10.2307/1940257

Drobyshev I.V., 1999, For. Ecol. Manage., 115, 71, 10.1016/S0378-1127(98)00437-X

Ehrenfeld J.G., 1980, Bull. Torrey Bot. Club, 107, 29, 10.2307/2484848

Emborg, 1998, For. Ecol. Manage., 106, 83, 10.1016/S0378-1127(97)00299-5

Facelli J.M., 1991, Bot. Rev., 57, 1, 10.1007/BF02858763

George L.O., 1999, Ecology, 80, 833, 10.1890/0012-9658(1999)080[0833:TFUAAE]2.0.CO;2

George L.O., 1999, Ecology, 80, 846, 10.1890/0012-9658(1999)080[0846:TFUAAE]2.0.CO;2

Godman R.M., 1960, Ecology, 41, 18, 10.2307/1931935

Harmon M.E., 1989, Ecology, 70, 48, 10.2307/1938411

Hatcher R.J., 1966, For. Chron., 42, 350, 10.5558/tfc42350-4

Hibbs D.E., 1982, Can. J. For. Res., 12, 522, 10.1139/x82-081

Huenneke L.F., 1983, York. Bull. Torrey Bot. Club, 110, 170, 10.2307/2996338

Huston M., 1979, Am. Nat., 113, 81, 10.1086/283366

Kneeshaw D.D., 1998, Ecology, 79, 783, 10.1890/0012-9658(1998)079[0783:CGCATR]2.0.CO;2

Krasny M.E., 1992, Can. J. For. Res., 22, 139, 10.1139/x92-019

Kurmis V., 1989, Can. J. Bot., 67, 2409, 10.1139/b89-308

Long T.J., 1996, Trees, 11, 1, 10.1007/s004680050051

Lorimer C.G., 1980, Ecology, 61, 1169, 10.2307/1936836

Lorimer C.G., 1994, J. Ecol., 82, 227, 10.2307/2261291

MacArthur R., 1967, Am. Nat., 101, 377, 10.1086/282505

Maguire D.A., 1983, Ecology, 64, 1367, 10.2307/1937491

McGee C.E., 1967, J. For., 65, 334

Mencuccini M., 1995, For. Ecol. Manage., 76, 109, 10.1016/0378-1127(95)03555-O

Molofsky J., 1992, Ecology, 73, 68, 10.2307/1938721

Monk C.C., 1985, Appalachians. Bull. Torrey Bot. Club, 12, 187, 10.2307/2996415

Nakashizuka T., 1989, Ecology, 70, 1273, 10.2307/1938186

Neiring W.A., 1955, Ecology, 36, 356, 10.2307/1933250

Nikolov N.T., 1992, Ecol. Model., 61, 149, 10.1016/0304-3800(92)90015-7

Nilsen E.T., 1999, Am. J. Bot., 86, 1597, 10.2307/2656796

Orwig D.A., 1995, Funct. Ecol., 9, 799, 10.2307/2389977

Pacala S.W., 1994, Am. Nat., 143, 222, 10.1086/285602

Pacala S.W., 1994, Can. J. For. Res., 24, 2172, 10.1139/x94-280

Pearcy R.W., 1983, Oecologia, 58, 19, 10.1007/BF00384537

Phillips D.L., 1985, For. Sci., 31, 226

Phillips D.L., 1990, Ecology, 71, 204, 10.2307/1940260

Putz F.E., 1983, Can. J. For. Res., 13, 1011, 10.1139/x83-133

Reader R.J., 1995, J. Veg. Sci., 6, 609, 10.2307/3236431

Rehfeldt G.F., 1971, For. Sci., 17, 454

Runkle J.R., 1981, Ecology, 62, 1041, 10.2307/1937003

Runkle J.R., 1982, Ecology, 63, 1533, 10.2307/1938878

Runkle J.R., 1990, Can. J. For. Res., 20, 632, 10.1139/x90-085

Schaetzl R.J., 1989, Vegetatio, 79, 165, 10.1007/BF00044908

Spies T.A., 1989, Ecology, 70, 543, 10.2307/1940198

Valverde T., 1997, Ecology, 78, 1555, 10.1890/0012-9658(1997)078[1555:CCRAFS]2.0.CO;2

Veblen T.T., 1982, Bull. Torrey Bot. Club, 109, 474, 10.2307/2996488

Veblen T.T., 1989, Ecology, 70, 541, 10.2307/1940197

Watt A.S., 1947, J. Ecol., 35, 1, 10.2307/2256497

Whitmore T.C., 1989, Ecology, 70, 536, 10.2307/1940195

Whitmore T.C., 1996, Philos. Trans. R. Soc. London B, 351, 1195, 10.1098/rstb.1996.0102

Whittaker R.H., 1956, Mountains. Ecol. Monogr., 26, 1, 10.2307/1943577

Williamson G.B., 1975, Ecology, 56, 727, 10.2307/1935509

Woods F.W., 1959, Ecology, 40, 349, 10.2307/1929751

Yamamoto S., 1995, J. Veg. Sci., 6, 875, 10.2307/3236402

Zhang Q., 1995, Can. J. For. Res., 25, 1627, 10.1139/x95-177

Thông tin
Thông tin xuất bản

Canadian Journal of Forest Research

Tập 30 Số 10

1617-1631

Thông tin tác giả