FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2323427424> ?p ?o ?g. }

• W2323427424 endingPage "231" @default.
• W2323427424 startingPage "231" @default.
• W2323427424 abstract "The vegetation on the trail behind a moving sand dune in a short-grass community near Olduvai Gorge, Tanzania, was sampled at intervals corresponding to the distance the dune traveled annually. These samples provided a 60-yr history of vegetational change following disturbance. The disturbed area was colonized by a sparse (12% cover) mixture of annual and perennial grasses and forbs during the first year after disturbance, followed by woody perennials the second year, and perennial grasses the fourth year. The original species composition was reached 30 yr after dune passage, but total vegetational cover after 60 yr remained lower in the trail than in the undisturbed community. Recovery of vegetation was slow due to the destruction of all vegetation in the path of the dune, the absence of a persistent seed pool, the large size of the disturbance, and intense grazing by large mammals. IN REGIONS OF THE WORLD WHERE THE VEGETATION has not been thoroughly described, it is often difficult to distinguish successional from climax communities or to derive the chronology of succession from the study of existing disturbances. Recognition of successional assemblages comes from familiarity with the flora and from long-term observations of vegetational change after disturbance. In such little-known areas as the Serengeti grasslands of northern Tanzania, abundant disturbances such as termite mounds, excavations by fossorial mammals, and severely trampled areas provide little information on vegetational succession, since neither the ages of these disturbances nor the dynamics of the rest of the community are known. However, in a Serengeti grassland north of Olduvai Gorge, the entire successional sequence from newly disturbed ground to climax vegetation can be observed in trails created by barchans (moving sand dunes). Since these trails provided an opportunity to study long-t.erm vegetational dynamics in a little-known East African grassland community, the vegetation and soil on the trail behind the largest remaining barchan were sampled in 1981 and 1984. The goals of the investigation were to reconstruct the dynamic history of the vegetation, to identify the main successional and dimax species of the region, and to determine the rate at which dormant seeds accumulate in the soil. COMMUNITY DESCRIPTION The barchan field north of Olduvai Gorge (3?00'S, 35025'E, altitude 1500 m) is located on a flat plain near the southeastern border of the Serengeti ecosystem. The soil is composed of alkaline ash originating from Oldoinyo Lengai, a vokano located 70 km to the northeast, and belongs to the subgroup Petrocalcic Calciustoll (de Wit 1978). A continuous cemented layer of calcium carbonate (calcrete) occurs in the soil at a depth of 40-65 cm. Rainfall averages 400-500 mm annually (Norton-Griffiths et al. 1975) and falls primarily from November through May. The barchans are blown in a westward direction 1518 m annually, leaving straight trails that are visible up to 4 km behind the dunes (Hay 1976). These barchans, known locally as the shifting sands of Olduvai Gorge, differ from U-shaped sand dunes by having horns that extend in front of the main body of the dune (Melton 1940) (Fig. 1). They are composed of a fine sand consisting of black ash that originated from Oldoinyo Lengai approximately 1300 yr ago (Hay 1976). Two active barchans, the only ones remaining out of hundreds that once traveled across this plain, are currently located 2 and 4.5 km north of Olduvai Gorge and are, respectively, 5 and 4 m high, 30 and 25 m long from the center of the advancing front to the trailing edge, and 60 and 35 m wide (Hay 1976). They cover a given point of ground for 12-24 months, during which time all vegetation is killed, unconsolidated sediment is incorporated into the dune (Hay 1976), and low hummocky ridges, 30-150 cm in height, are deposited on either side. In 1981 the BIOTROPICA 18(3): 231-235 1986 231 I Received 26 February 1985, revision accepted 27 July 1985. 2 Present address: Cornell Plantations, Cornell University, Ithaca, N.Y. 14853, U.S.A. This content downloaded from 157.55.39.220 on Fri, 02 Sep 2016 04:03:27 UTC All use subject to http://about.jstor.org/terms soil layer above the calcrete was 60-65 cm deep in front and to the sides of the dune, 55 cm deep at 2 m behind the dune, and 40-65 cm deep at other random locations in the trail. With the exception of a few isolated trees of Acacia tortilis, the plain was vegetated by grasses and small forbs that were grazed to 3 cm in height by wildebeest (Connochaetes taurinus Burchell), Thomson's gazelle (Gazella thomsoni Gunther), and zebra (Equus burchelli Gray), as well as domesticated cattle and goats. Trees of A. tortilis, located predominantly on nearby hills and on the low hummocks at both sides of the barchan trails, were browsed by giraffe (Girafa camelopardalis L.) and goats. In the vicinity of the dunes, the undisturbed short-grass community covered 65 percent of the ground and was dominated by the stoloniferous grasses Cynodon dactylon, Cynodon plectostachyus, Digitaria macroblephara, Sporobolus ioclados, and Sporobolus kentrophyllus. (Plant nomendature follows Clayton 1970, Clayton et al. 1974, and Clayton & Renvoize 1982 for grasses and Agnew 1974 for forbs and shrubs.) METHODS AND MATERIALS The aboveground cover of all plant species was recorded in 1981 and 1984 at regular intervals along a 1-km transect positioned behind and perpendicular to the largest remaining dune. In 1981 species cover was estimated visually in releves extending across the width of the trail, but in 1984 cover was estimated within a frame (1 m2) that had been divided into 0.04-M2 sections. At each interval, 5 cover estimates were made using the frame, one on a line in the middle of the trail and the others at distances of 5 and 10 m on either side of the line. The first vegetation samples in both years were taken at the trailing edge of the dune (0 m), at a distance corresponding to the location of the trailing edge at the end of the preceding dry season (6 m), and at the location of the dune one year earlier (16 m). Successive vegetation samples were taken at intervals of 16 m for a distance of 160 m (10 yr), followed by intervals of 32 or 64 m for a total distance of 1000 m (ca. 60 yr). Since the quadrat method used in 1984 was judged to be more precise than the releves, the quadrat results will be presented here. The accumulation of dormant seeds in the soil after disturbance was investigated by extracting seeds from the dune sand and surface soils (0-5 cm depth) collected from the dune, from the undisturbed community, and from the trail at 0, 10, 20, 40, 60, 80, and 100 m behind the dune (5 replicates/location). Soil samples were collected near the end of the growing season in April and before dispersal of the current year's seeds. Seeds were separated from composite soil samples of each location by flotation in a strong salt solution (2 replicates) (Malone 1967). 232 Belsky and Amundson FIGURE 1. The largest remaining barchan on a short-grass plain north of Olduvai Gorge, Tanzania." @default.
• W2323427424 created "2016-06-24" @default.
• W2323427424 creator A5040203065 @default.
• W2323427424 creator A5045171524 @default.
• W2323427424 date "1986-09-01" @default.
• W2323427424 modified "2023-09-24" @default.
• W2323427424 title "Sixty Years of Successional History Behind a Moving Sand Dune Near Olduvai Gorge, Tanzania" @default.
• W2323427424 cites W1972778785 @default.
• W2323427424 cites W1985136633 @default.
• W2323427424 cites W1985263726 @default.
• W2323427424 cites W1996670866 @default.
• W2323427424 cites W2037046619 @default.
• W2323427424 cites W2060872373 @default.
• W2323427424 cites W2087641521 @default.
• W2323427424 cites W2491533811 @default.
• W2323427424 cites W2497141028 @default.
• W2323427424 cites W2797977998 @default.
• W2323427424 cites W3049151984 @default.
• W2323427424 doi "https://doi.org/10.2307/2388490" @default.
• W2323427424 hasPublicationYear "1986" @default.
• W2323427424 type Work @default.
• W2323427424 sameAs 2323427424 @default.
• W2323427424 citedByCount "40" @default.
• W2323427424 countsByYear W23234274242013 @default.
• W2323427424 countsByYear W23234274242015 @default.
• W2323427424 countsByYear W23234274242020 @default.
• W2323427424 countsByYear W23234274242022 @default.
• W2323427424 crossrefType "journal-article" @default.
• W2323427424 hasAuthorship W2323427424A5040203065 @default.
• W2323427424 hasAuthorship W2323427424A5045171524 @default.
• W2323427424 hasConcept C114793014 @default.
• W2323427424 hasConcept C127313418 @default.
• W2323427424 hasConcept C150117547 @default.
• W2323427424 hasConcept C151730666 @default.
• W2323427424 hasConcept C166957645 @default.
• W2323427424 hasConcept C167110946 @default.
• W2323427424 hasConcept C18903297 @default.
• W2323427424 hasConcept C205649164 @default.
• W2323427424 hasConcept C2775915184 @default.
• W2323427424 hasConcept C2778456499 @default.
• W2323427424 hasConcept C2779357621 @default.
• W2323427424 hasConcept C53570757 @default.
• W2323427424 hasConcept C86803240 @default.
• W2323427424 hasConcept C91375879 @default.
• W2323427424 hasConceptScore W2323427424C114793014 @default.
• W2323427424 hasConceptScore W2323427424C127313418 @default.
• W2323427424 hasConceptScore W2323427424C150117547 @default.
• W2323427424 hasConceptScore W2323427424C151730666 @default.
• W2323427424 hasConceptScore W2323427424C166957645 @default.
• W2323427424 hasConceptScore W2323427424C167110946 @default.
• W2323427424 hasConceptScore W2323427424C18903297 @default.
• W2323427424 hasConceptScore W2323427424C205649164 @default.
• W2323427424 hasConceptScore W2323427424C2775915184 @default.
• W2323427424 hasConceptScore W2323427424C2778456499 @default.
• W2323427424 hasConceptScore W2323427424C2779357621 @default.
• W2323427424 hasConceptScore W2323427424C53570757 @default.
• W2323427424 hasConceptScore W2323427424C86803240 @default.
• W2323427424 hasConceptScore W2323427424C91375879 @default.
• W2323427424 hasIssue "3" @default.
• W2323427424 hasLocation W23234274241 @default.
• W2323427424 hasOpenAccess W2323427424 @default.
• W2323427424 hasPrimaryLocation W23234274241 @default.
• W2323427424 hasRelatedWork W2004138470 @default.
• W2323427424 hasRelatedWork W2100601043 @default.
• W2323427424 hasRelatedWork W2323427424 @default.
• W2323427424 hasRelatedWork W2887497577 @default.
• W2323427424 hasRelatedWork W2974881989 @default.
• W2323427424 hasRelatedWork W3033003123 @default.
• W2323427424 hasRelatedWork W3041710622 @default.
• W2323427424 hasRelatedWork W4254395767 @default.
• W2323427424 hasRelatedWork W4282582161 @default.
• W2323427424 hasRelatedWork W4292730568 @default.
• W2323427424 hasVolume "18" @default.
• W2323427424 isParatext "false" @default.
• W2323427424 isRetracted "false" @default.
• W2323427424 magId "2323427424" @default.
• W2323427424 workType "article" @default.