Seasonal pattern of biomass allocation in flowering and nonflowering specimens of three Pinguicula species

Abstract

KARLSSON, P. S. 1986. Seasonal pattern of biomass allocation in flowering and nonflowering specimens of three Pinguicula species. Can. J. Bot. 64: 2872 -2877. The seasonal patterns of biomass allocation in flowering and nonflowering specimens of Pinguicula alpina L., P. villosa L., and P. vulgaris L. were compared in a subarctic environment. Pinguicula alpina had a large perennial root system, comprising 50% of the nonreproductive biomass. The other two species had smaller, annual roots, representing 5 -10% of their biomass. Nonflowering specimens usually had winter buds about twice as large as flowering specimens, P. vulgaris varied, however, with site in this respect. Flowering P. alpina allocated approximately equal proportions of biomass to reproduction (flower stalk, capsule, and seeds) and over-wintering organs (bud and roots), while P. villosa's investment in reproduction was about five times that invested in the winter bud. For P. vulgaris, no correlation was found between the size of reproductive organs and the size of the bud. The number of seeds produced per capsule varied from 30 in P. villosa to 110-140 in the other two species. Seed weight was lower in P. alpina (15 pglseed) than in P. vulgaris (24 pg) and P. villosa (28 pg). Plant biomass and reproductive effort varied between sites for P. vulgaris; however, this variation was apparently not related to differences in nutrient availability between sites. KARLSSON, P. S. 1986. Seasonal pattern of biomass allocation in flowering and nonflowering specimens of three Pinguicula species. Can. J. Bot. 64 : 2872 -2877. Les patrons saisonniers de l'affectation de la biomasse chez des spCcimens en fleurs et sans fleurs du Pinguicula alpina L., du P. villosa L. et du P. vulgaris L. ont Ct C cornparks dans un milieu sub-arctique. Le P. alpina avait un important systbme racinaire pCrennant comprenant 50% de la biomasse non-reproductrice. Les deux autres espbces avaient des racines annuelles plus petites reprksentant 5-10% de leur biomasse. Les spCcimens sans fleurs avaient d'habitude des bourgeons d'hiver environ deux fois plus gros que ceux des spCcimens en fleurs, mais cependant, en ce qui concerne le P. vulgaris, cela variait avec le site. Les spCcimens en fleurs du P. alpina affectaient des proportions de biomasse i peu prbs Cgales i i la reproduction (pCdicelle floral; capsule et graines) et aux organes hivernaux (bourgeons et racines), tandis que chez le P. villosa l'investissement dans la reproduction Ctait d'environ cinq fois plus que l'investissement dans le bourgeon d'hiver. Pour le P. vulgaris, aucune corklation n'a Ct C dCcelCe entre la taille des organes reproducteurs et la taille du bourgeon. Le nombre de graines produites par capsule variait de 30 chez le P. villosa i 110-140 chez les deux autres espbces. Le poids des graines Ctait plus faible chez le P. alpina (15 pglgraine) que chez le P. vulgaris (24 pg) et la P. villosa (28 pg). La biomasse de la plante et l'effort reproducteur variait selon les sites pour le P. vulgaris; cependant, cette vari...

Phenomorphology and reproductive biology ofPinguicula longifoliaRamond ex DC. subsp.longifolia(Lentibulariaceae), a carnivorous endemic plant of the Pyrenees

“…Most of ovules develop into seeds (pers. observation), and the number of seeds per fruit is similar or higher than in its European congeners (P. alpina, P. villosa and P. vulgaris) (Karlsson, 1986). These results, together with the particular strategy of seeds dispersal and the easiness of vegetative propagation, suggest that P. longifolia reproduces without problems, and that it is a plant well adapted to the habitat where it lives.…”

“…Several studies have focused on the cytology, physiology and feeding ecology of Pinguicula (Heslop-Harrison and Knox, 1971 ;Karlsson and Carlsson, 1984 ;Karlsson, 1986 ;Karlsson et al, 1987Karlsson et al, , 1990Zamora, 1990 ;Antor and Garcia, 1994); however, there are very few references on their biology and reproduction in natural conditions (see Molau, 1993). The aim of this study is to provide information about some of these aspects (life cycle, breeding system, pollinators, reproductive succss ... )…”

Competition between Sphagnum fuscum and Drosera rotundifolia: A Case of Ecosystem Engineering

“…It has been suggested that due to the continuous upward movement of Sphagnum, the co-occurring vascular plants need to allocate resources to vertical growth to keep pace with the Sphagnum carpet (Backeus 1985, Thum 1988, Karlsson 1986, Svensson et al 1993, Malmer et al 1994. The present results support this hypothesis.…”

Size-dependent reproductive and vegetative allocation in Arum italicum (Araceae)

“…Within a species, SRE values were shown to vary markedly within and among populations (e.g., Douglas 198 1;Ashmun et al 1985;Karlsson 1986;Hartnett 1990) and between years (Ohlson 1988). However, much of the variation in SRE can be accounted for by size-dependent reproductive allocation, rather than external effects (Samson and Werk 1986;Weiner 1988).…”