scholarly journals Scientific results of the BRYOTROP expedition to Zaire and Rwanda 7. Life strategies of epiphytic bryophytes from tropical lowland and montane forests, ericaceous woodlands and the Dendrosenecio subpáramo of the eastern Congo basin and the adjacent mountains (Parc National de Kahuzi-Biega/Zaire, Forêt de Nyungwe/Rwanda)

1995 ◽  
Vol 11 (1) ◽  
pp. 129-149
Author(s):  
Wolfgang Frey ◽  
Harald Kürschner ◽  
Ulrike H. Seifert
Keyword(s):  
Altitudinal Gradient ◽  
Reproductive Effort ◽  
Congo Basin ◽  
Life Strategy ◽  
Life Strategies ◽  
Rain Forests ◽  
Tropical Lowland ◽  
Alpine Zone ◽  
Montane Zone ◽  
Epiphytic Communities

Life strategies of epiphytic bryophytes are studied along an altitudinal gradient from the eastern Congo basin (tropical lowland zone) to the mountains of the East-African graben (tropical subalpine/alpine Zone; BRYOTROP III-transect). Three strategies, Colonists, Perennial shuttle species and Perennial stayers can be observed, which are further subdivided according to their reproduction tactic (high sexual reproductive effort, high asexual reproductive effort, moderately or low sexual and asexual reproductive effort). Of these, only taxa with a long life span (perennials) are of importance, indicating the unchanging and constant ecological conditions and long-lasting microsites, provided by the epiphytic habitats. The basis for the life strategy pattern analysis along the altitudinal gradient were plant sociological investigations and the determination of the mean percentage cover values for the different life strategy categories. By this, the distribution and occurrence of the different strategies within the communities and the altitudinal zones can be shown.  Typical for the epiphytes of the primary rain-forests of the tropical lowland and lower montane zone are Perennial shuttle species and Perennial stayers with moderately or low sexual and asexual reproductive effort. This strategy obviously is favoured by the well balanced, high temperature and humidity regime of these zones and typical of most of the liverworts, dominating the epiphytic communities. They are replaced in the montane rain-forests and cloudy moss forests of the upper tropical montane zone by Perennial shuttle species with high asexual reproductive effort, regenerating mainly by propagules and clonal growth. Within the secondary woodlands of this zone and the unique ericaceous woodlands and subpáramo of the African volcanos, Perennial shuttle species and Perennial stayers with high sexual reproductive effort reach a maximum, building regularly sporophytes under the already xeric and strong diurnal climatic conditions of the subalpine/alpine zone. This reproduction strategy is typical of epiphytic communities of xerophytic woodlands. The frequent change within the life strategy spectra of the different altitudinal zones indicates, that life strategies can be seen as a set of co-evolved adaptive traits, which grow and evolve within different taxa under similar ecological conditions.

scholarly journals Wissenschaftliche Ergebnisse der BRYOTROP-Expedition nach Zaire und Rwanda 6. Lebensformen und Adaptionen zur Wasserleitung und Wasserspeicherung in epiphytischen Moosgesellschaften im östlichen Kongobecken und den angrenzenden Gebirgsstöcken (Parc National de Kahuzi-Biega/Zaire, Forêt de Nyungwe/ Rwanda)

1995 ◽  
Vol 11 (1) ◽  
pp. 87-117 ◽  
Author(s):  
Harald Kürschner ◽  
Ulrike H. Seifert
Keyword(s):  
Water Vapour ◽  
Life Form ◽  
Wide Spectrum ◽  
Life Forms ◽  
Congo Basin ◽  
Percent Cover ◽  
Ecological Gradient ◽  
Alpine Zone ◽  
Montane Zone ◽  
Central Strand

Life forms, water conducting and water storing structures of epiphytic bryophytes are studied along an altitudinal gradient from the eastern Congo basin (tropical lowand zone) to the mountains of the East-African graben (tropical subalpine/alpine zone; BRYOTROP III-transect). Based on a phytosociological analysis, these adaptations were put in relation to the distribution pattern of the bryophyte communities, as well as to the ecological gradient. The interpretation is based on the mean percent cover of each group. The tropical lowland zone is dominated by the life form mat, which is distinctly correlated with watersacs and taxa of the Jubulaceae, Lejeuneaceae and Radulaceae. In the following perhumid montane zone a clear alteration concerning the life form and the adaptations can be observed. The physiognomy of the primary rain-forests now is dominated by fan-forming Plagiochila species which are standing off the phorophyte by its flattened shoots. They are able to condensate water vapour from the fogs as well as using the low light intensities. Within the epiphytes of the bamboo zone of the upper montane zone, similar adaptation strategies to those of the lowland zone can be observed. The communities of the anthropogeneous montane woodlands of this zone, which are rich in mosses, show an ecomorphological wide spectrum [weft and tall-turfs correlated with a central strand (hadrome), hyalocysts and rhizoids]. Within the tropical subalpine/alpine zone exposed to great diurnal variations of climate, mat, weft and cushion-forming tall-turfs dominate, indicating the more xeric conditions (drought stress) by 88 water storing structures (alar cells, central strand, hyalocysts, rhizoids). In this zone, also structures reach a high mean percent cover, which enables the condensation of water vapour from the fog and mist rising from the upper montane zone or which show a groove-like arrangement of the leaflets. This may be recognized as a mechanism enabling a permanent water supply as well as a drain off of surplus water.

scholarly journals Reproductive effort as an element of life strategy of Lythrum salicaria L. populations

2012 ◽  
Vol 60 (2) ◽  
pp. 105-110
Author(s):  
Bożenna Czarnecka ◽  
Magdalena Franczak ◽  
Katarzyna Nowak
Keyword(s):  
Biomass Allocation ◽  
Reproductive Strategies ◽  
Reproductive Effort ◽  
Population Level ◽  
Lythrum Salicaria ◽  
Purple Loosestrife ◽  
Life Strategy ◽  
Life Strategies ◽  
Habitat Conditions ◽  
Different Populations

The aim of the study was to compare some life strategy traits of individuals of Purple Loosestrife <i>Lythrum salicaria</i> within three meadow populations existing under various habitat conditions. The study attempted to answer the following questions: Do different habitat conditions affect the biomass allocation between particular organs of individuals? Can the individuals belonging to different populations of the same species realise their own unique reproductive strategy, in other words, can their reproductive effort represent various levels? In the case of <i>L. salicaria</i> the reproductive effort, measured by the participation of infl orescence biomass in the biomass of aboveground parts of genets, exhibits similar values (14.2-15.1%) in all the study populations, despite their habitat conditions. This fact proves that at the population level, the reproductive effort is relatively stable. Great differences are visible in the case of particular individuals within each of the populations. Specific genets in a population, depending on the habitat microstructure and the biotic relations with other individuals both of their own and other species, may realise their own reproductive strategies, being a part of their life strategies.

scholarly journals Life strategies of plants of meander bars

2021 ◽  
Vol 38 ◽  
pp. 00113
Author(s):  
Marya Shakleina ◽  
Natalya Savinykh
Keyword(s):  
Environmental Impact ◽  
Life Span ◽  
Vegetative Propagation ◽  
Root Systems ◽  
Life Strategy ◽  
Life Strategies ◽  
Seed Propagation ◽  
Silene Tatarica

The article generalizes the data on life strategy of plants in meander bars by the example of the species Limosella aquatica L., Silene tatarica (L.) Pers. and Petasites spurius (Retz.) Rchb., taking into account their life span and centres of environmental impact of a specimen, as well as peculiar features of sustaining a coenopopulation. The annual monocarpic L. aquatica combines its typical ruderal strategy of leaving numerous posterity with vegetative accrescence and iterative branching. The taproot perennial S. tatarica shows a competitor-ruderal strategy: plants entrench themselves and repeatedly territory development the help of root systems, still the coenopopulation (CP) is sustained by means of seed propagation and, possibly, as a kind of support, in a vegetative way, using a bank of dormant buds. Ruderal-competitor strategy of P. spurius is supported by vegetative propagation, development, and entrenchment on the territory by means of clones constantly and regularly renewed. So life of plants belonging to different biomorphs in conditions of meander bars is provided by a full or partial shift to ruderal life strategy.

Do Tropical Storm Regimes Influence the Structure of Tropical Lowland Rain Forests?1

Biotropica ◽  
10.1646/02136 ◽  
2003 ◽  
Vol 35 (2) ◽  
pp. 166 ◽  
Author(s):  
Roland C. de Gouvenain ◽  
John A. Silander
Keyword(s):  
Tropical Storm ◽  
Rain Forests ◽  
Tropical Lowland

Altitudinal variation in reproductive strategy of the toad-headed lizard, Phrynocephalus vlangalii in North Tibet Plateau (Qinghai)

2007 ◽  
Vol 28 (4) ◽  
pp. 509-515 ◽  
Author(s):  
Yuan-Ting Jin ◽  
Nai-Fa Liu
Keyword(s):  
Litter Size ◽  
Altitudinal Gradient ◽  
Reproductive Effort ◽  
Reproductive Investment ◽  
Reproductive Traits ◽  
Tibet Plateau ◽  
Sand Lizard ◽  
Survival And Growth ◽  
The Common ◽  
Anatomical Constraints

Abstract Phrynocephalus vlangalii, a toad-headed viviparous sand lizard, is endemic in the Northern Tibet (Qinghai) Plateau in China. Lizards were collected from 14 localities along the large altitudinal gradient (2289-4565 m a.s.l) to analyze the variation of reproductive traits among localities. Both litter size and mean offspring (scaled embryo) mass were positively correlated with female snout-vent length (SVL). Females produced fewer and larger offspring with increasing elevation when the effect of body size (SVL) was removed. This strategy may possibly be correlated with early survival and growth of offspring. The decreased litter size cline along altitudinal gradient might be correlated with more anatomical constraints at higher altitudes. The lizard has lower coefficient of variation (CV) of litter size at higher environments. Moreover, females from higher elevations had less reproductive investment (relative litter mass, RLM). Study concluded that P. vlangalii fit into the common pattern of higher elevation animals that have smaller clutches of larger offspring and lower reproductive effort.

The biosystematics and evolution of the Polyalthia hypoleuca species complex (Annonaceae) of Malesia. II. Comparative distributional ecology

1990 ◽  
Vol 6 (4) ◽  
pp. 387-408 ◽  
Author(s):  
Steven H. Rogstad
Keyword(s):  
Tree Species ◽  
Species Complex ◽  
Sympatric Species ◽  
Growth Characteristics ◽  
Rain Forests ◽  
Tropical Lowland ◽  
Seedling Germination ◽  
Well Differentiated ◽  
Substrate Types ◽  
Germination Requirements

ABSTRACTOne component of the high organismal diversity of tropical lowland rain forests is the existence of series of closely related, sympatric species. For example, the six distinct tree species of the monophyletic Polyalthia hypoleuca complex regularly grow sympatrically in various combinations throughout the rain forests of Malesia. Theoretical and empirical evidence has been presented indicating that the members of such series either (1) are well differentiated with respect to at least one major niche component; or (2) may lack differentiated niches. In this study, certain sympatric members of the complex are shown to have clearly diverged in autecological characteristics that affect their distribution including: (1) P. glauca, P. hypoleuca, and P. sumatrana differ in growth characteristics, height at maturity, seedling germination requirements, and are found on soils with differing degrees of hydration; (2) P. discolor grows to a different height and on different substrate types than does P. multinervis; and (3) P. glauca and P. hypoleuca seedlings differ in transpiration characteristics and response to flooding and drought.

Design for End-of-Life: Repair, Recondition, Remanufacture or Recycle?

2004 ◽  
Author(s):  
Andrew King ◽  
Stuart Burgess ◽  
Winnie Ijomah ◽  
Chris McMahon
Keyword(s):  
European Union ◽  
End Of Life ◽  
Intrinsic Value ◽  
Embodied Energy ◽  
Life Strategy ◽  
Life Strategies ◽  
The European Union ◽  
Alternative Strategies ◽  
Definition Of ◽  
Compare And Contrast

Between 1980 and 1997, municipal waste in OECD (Organisation for Economic Co-operation and Development) countries increased by around 40%. The European Union has responded by introducing legislation on extended producer responsibility (EPR). This paper further explains the context of this new legislation and describes, compares and then contrasts the four alternative strategies to reducing end-of-life waste: namely repairing, reconditioning, remanufacturing or recycling. It also introduces a more robust definition of remanufacturing, validated by earlier research, which differentiates it from repair and reconditioning. From a consideration of the different factors involved, it concludes that remanufacturing may often be a strong strategy. This is based on the fact that it preserves both the embodied energy of virgin production (thus reducing the environmental impact) and the intrinsic “value adding” process of the producer (thus increasing the manufacturer’s profitability). As a result, this new environmental policy is likely to lead to significant increases in remanufacturing as an end-of-life strategy in the European Union. However, effective end-of life strategies are dictated by product characteristics and therefore vary from product to product (Rose et al, 1998). Thus further research is required to compare and contrast the effectiveness of remanufacturing and alternative end-of-life strategy for particular product types.

Estimating the diversity of wood-decaying polypores in tropical lowland rain forests in Malaysia: the effect of sampling strategy

2014 ◽  
Vol 24 (2) ◽  
pp. 393-406 ◽  
Author(s):  
Satoshi Yamashita ◽  
Tsutomu Hattori ◽  
Su See Lee ◽  
Kimiko Okabe
Keyword(s):  
Sampling Strategy ◽  
Rain Forests ◽  
Tropical Lowland

scholarly journals ­Reproductive strategies of two common sympatric Mediterranean sponges:Dysidea avara(Dictyoceratida) andPhorbas tenacior(Poecilosclerida)

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5458 ◽  
Author(s):  
Sonia de Caralt ◽  
Janina González ◽  
Xavier Turon ◽  
María J. Uriz
Keyword(s):  
Reproductive Effort ◽  
Reproductive Traits ◽  
Reproductive Period ◽  
Life Cycles ◽  
Life Strategy ◽  
Larval Size ◽  
Dysidea Avara ◽  
Species Specific ◽  
June July ◽  
Benthic Ecosystems

Despite their abundance in benthic ecosystems, life cycles and reproductive features of most sponge species remain unknown. We have studied the main reproductive features of two demosponges,Dysidea avaraandPhorbas tenacior,belonging to phylogenetically distant groups: Orders Dictyoceratida and Poecilosclerida, respectively. Both sponges are abundant and share habitat in the Mediterranean rocky sublittoral. They brood parenchymella larvae with different morphology and behaviour. Sampling was conducted monthly over a two-year period in a locality where both species coexist. The two species reproduced in spring-summer, and presented species-specific reproductive features despite being subject to the same environmental conditions.D. avarahas a shorter reproductive period thanP. tenacior, ending before the peak of temperature in summer, while the reproductive period ofP. tenaciorlasts until beginning of autumn. Brooding larvae were present in June-July inD. avara, and in August-October inP. tenacior. Larval size, reproductive effort and number of larvae produced (measured the month with the maximum production) were significantly higher inD. avarathan inP. tenacior. A higher reproductive effort and larval traits point to a more opportunistic life strategy inD. avarathan inP. tenacior.A lack of overlap in the timing of larval release, as well as different reproductive traits, may reduce competition and facilitate the coexistence of these two sympatric and abundant sponges.

Sign in / Sign up

Export Citation Format

Share Document