Intra- and inter-specific competition between seedlings of Acacia etbaica and a perennial grass (Hyparrenia hirta)

被引:58
作者
Fetene, M [1 ]
机构
[1] Univ Addis Ababa, Fac Sci, Dept Biol, Addis Ababa, Ethiopia
关键词
Acacia etbaica; Hyparrenia hirta; inter-specific competition; intra-specific competition;
D O I
10.1016/S0140-1963(03)00052-1
中图分类号
Q14 [生态学(生物生态学)];
学科分类号
071012 ; 0713 ;
摘要
Intra- and inter-specific competition between seedlings of Acacia etbaica Schweinf. and the grass Hyparrenia hirta (L.) Stapf. was studied to evaluate the influence of the perennial grass on the establishment of the tree seedlings. The experiment was conducted using a replacement series in which plants were grown in a greenhouse at an overall density of six individuals per pot, providing combinations of the two species from 0:6 and 6:0. Indices of intra- and interspecific competition, relative crowding coefficients and relative yield totals (RYTs) were calculated from the dry weight data. For both shoots and roots, the crowding coefficient of Hyparrenia towards Acacia was five- to ten-fold that of Acacia towards Hyparrenia, which indicated a high competitive strength for the grass species. RYT values of the two species averaged 1.25, indicating some degree of resource complimentarity. Both species had comparable intra-specific competition based on shoot yield. However, based on the root yield, intra-specific competition of Hyparrenia was slightly lower than that of Acacia. Inter-specific competition of Hyparrenia on the root yield of Acacia was more than five times greater than vice versa. With more crowding, shoot/root ratio decreased more in Hyparrenia than in Acacia for pure stands as well as for mixtures which indicated that Hyparrenia could adjust biomass allocation. In general, the results indicated that Hyparrenia was competitively aggressive towards Acacia and may inhibit the growth of tree seedlings when the latter are planted within the grass community. Implications of the findings in terms of land reclamation efforts are discussed. (C) 2003 Elsevier Science Ltd. All rights reserved.
引用
收藏
页码:441 / 451
页数:11
相关论文
共 26 条
[1]  
[Anonymous], [No title captured]
[2]  
[Anonymous], ECOSYSTEMS WORLD B
[3]   AN ANALYSIS OF COMPETITION BETWEEN BARLEY AND WHITE PERSICARIA II. FACTORS DETERMINING THE COURSE OF COMPETITION [J].
Aspinall, D. .
ANNALS OF APPLIED BIOLOGY, 1960, 48 (03) :637-654
[4]   INFLUENCES OF TREES ON SAVANNA PRODUCTIVITY - TESTS OF SHADE, NUTRIENTS, AND TREE-GRASS COMPETITION [J].
BELSKY, AJ .
ECOLOGY, 1994, 75 (04) :922-932
[5]   TREE GRASS RATIOS IN EAST-AFRICAN SAVANNAS - A COMPARISON OF EXISTING MODELS [J].
BELSKY, AJ .
JOURNAL OF BIOGEOGRAPHY, 1990, 17 (4-5) :483-489
[6]   INTER-SPECIFIC COMPETITION BETWEEN SEEDLINGS OF PINUS-RADIATA, EUCALYPTUS-REGNANS AND ACACIA-MELANOXYLON [J].
BI, HQ ;
TURVEY, ND .
AUSTRALIAN JOURNAL OF BOTANY, 1994, 42 (01) :61-70
[7]   ADAPTIVE STRATEGIES OF DESERT GRASSES IN SAUDI-ARABIA [J].
BOKHARI, UG ;
ALYAEESH, F ;
ALNORI, M .
JOURNAL OF RANGE MANAGEMENT, 1987, 40 (01) :19-22
[8]  
DE WIT C. T., 1965, NETH J AGR SCI, V13, P212
[9]   ON THE ANALYSIS OF COMPETITION WITHIN 2-SPECIES MIXTURES OF PLANTS [J].
FIRBANK, LG ;
WATKINSON, AR .
JOURNAL OF APPLIED ECOLOGY, 1985, 22 (02) :503-517
[10]  
Harper J. L., 1977, POPULATION BIOL PLAN