C4 grasses in boreal fens:: their occurrence in relation to microsite characteristics

被引:14
作者
Kubien, DS [1 ]
Sage, RF [1 ]
机构
[1] Univ Toronto, Dept Bot, Toronto, ON M5S 3B2, Canada
基金
加拿大自然科学与工程研究理事会;
关键词
Muhlenbergia glomerata; C(4); fens; climate; temperature;
D O I
10.1007/s00442-003-1369-2
中图分类号
Q14 [生态学(生物生态学)];
学科分类号
071012 ; 0713 ;
摘要
C(4) plants are rare in cool climates, an ecological pattern attributable to their poor photosynthetic performance at low temperatures relative to C(3) species. However, some C(4) species are able to persist at high latitudes and high elevations, possibly due to the characteristics of the particular microsites they inhabit in these otherwise unfavourable environments. One such species is Muhlenbergia glomerata, which occurs above 60degreesN in Canada and is found in the atypical C(4) habitat of boreal fens. In this study, we evaluate how microsite features affect the success of M. glomerata in boreal fens. We surveyed 19 populations across northern Ontario during the summers of 1999 and 2000. The ground coverage by woody vegetation was the most important parameter affecting the presence or absence of M. glomerata. Woody plants covered over 50% of the ground area in plots where M. glomerata is absent, but less than 20% where it is present. The minimum light intensity threshold for the presence of the C(4) species was about 32% of full-sunlight at plant height. Surprisingly, in boreal fens M. glomerata was largely restricted to the wetter moss hollows, rather than occurring on the dry hummocks where its greater water use efficiency might have been advantageous. Woody species dominated the hummocks, but were uncommon in the hollows. In these cool northern climates M. glomerata apparently persists because sufficient periods of temperatures favourable to C(4) photosynthesis occur, but this persistence likely requires some factor that suppresses the woody vegetation.
引用
收藏
页码:330 / 337
页数:8
相关论文
共 39 条
[21]  
OSMOND CB, 1982, ENCY PLANT PHYSL B, V12, P480
[22]   Photosynthetic performance at low temperature of Bouteloua gracilis Lag., a high-altitude C4 grass from the Rocky Mountains, USA [J].
Pittermann, J ;
Sage, RF .
PLANT CELL AND ENVIRONMENT, 2000, 23 (08) :811-823
[23]   The response of the high altitude C4 grass Muhlenbergia montana (Nutt.) AS Hitchc. to long- and short-term chilling [J].
Pittermann, J ;
Sage, RF .
JOURNAL OF EXPERIMENTAL BOTANY, 2001, 52 (357) :829-838
[24]   MUHLENBERGIA, SUBGENUS MUHLENBERGIA (GRAMINEAE) IN NORTH AMERICA [J].
POHL, RW .
AMERICAN MIDLAND NATURALIST, 1969, 82 (02) :512-&
[25]   Microsite characteristics of Muhlenbergia richardsonis (Trin.) Rydb., an alpine C4 grass from the White Mountains, California [J].
Sage, RF ;
Sage, TL .
OECOLOGIA, 2002, 132 (04) :501-508
[26]  
Sage RF., 1999, C4 plant biology, P313
[27]   C-4 GRASSES FROM THE BOREAL FOREST REGION OF NORTHWESTERN CANADA [J].
SCHWARZ, AG ;
REDMANN, RE .
CANADIAN JOURNAL OF BOTANY-REVUE CANADIENNE DE BOTANIQUE, 1988, 66 (12) :2424-2430
[28]   Myrica gale L. [J].
Skene, KR ;
Sprent, JI ;
Raven, JA ;
Herdman, L .
JOURNAL OF ECOLOGY, 2000, 88 (06) :1079-1094
[29]   PHOTOSYNTHETIC RESPONSES TO IRRADIANCE IN 3 FOREST UNDERSTORY SPECIES OF THE C-4 GRASS GENUS MUHLENBERGIA [J].
SMITH, M ;
MARTIN, CE .
BOTANICAL GAZETTE, 1987, 148 (03) :275-282
[30]  
Taylor SW, 1997, FIELD GUIDE CANADIAN