Studies in the Numerical Analysis of Complex Rain-Forest Communities: II. The Problem of Species-Sampling

Webb, L. J.; Tracey, J. G.; Williams, W. T.; Lance, G. N.

doi:10.2307/2257891

Cited by 78 publications

(44 citation statements)

References 7 publications

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“…This implies a constraint on the assembly of species sizes, probably a limit on the ability of large-biomass species to coexist, eventually reflecting competitive constraint. This parallells the conclusion of Webb et al (1967) for tropical rain forests, of the importance for community structure of potentially-large species, rather than of large individuals.…”

Section: Discussionsupporting

confidence: 76%

Community structure and assembly rules in a dune slack: Variance in richness, guild proportionality, biomass constancy and dominance/diversity relations

Wilson

Gitay

1995

Vegetatio

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There is still disagreement as to whether plant communities can be described as conforming to certain assembly rules. We searched for such rules in the vegetation of four dune slacks in west Wales by examining variance in richness, guild proportionality, biomass constancy and dominance/diversity relations. To test for the occurrence of niche limitation, variance in quadrat species-richness was compared to null models of species occurrence. Using an Overall-model, one site showed a deficit of variance, but this disappeared when a Patch-model analysis was used. It therefore seems likely that the effect observed was due to equality in the species pools adapted to different microenvironments. The proportional representation of functional guilds was examined, in guilds based on morphology and life history. Significant constancy of guild proportions was seen for the annual guild in the only site in which it occurred, perhaps reflecting a regeneration niche. Total biomass per quadrat was examined, and compared to a model in which the biomass of each species was determined at random from the biomasses of that species at the site. Surprisingly, the observed biomasses showed no departure from the null model. However, there was considerable discrepancy from an alternative null model in which biomasses were allocated at random irrespective of species. This would imply that competition limits species coexistence, rather than performance. Examination of the proportions of species from different potential-size classes in each quadrat gave limited confirmation. The local abundance of species (mean biomass) was significantly correlated with the frequency of the species within a site, parallelling the geographical-range/local-abundance correlation previously reported. Five dominance/diversity models were fitted to the biomass data. The best fits were given by the Geometric or the General Lognormal models, though which fitted best varied between and within sites. Between sites, there was some indication of a consistent difference in Preston's 'gamma'. Most of the results are compatible with Gleason's Individualistic concept of the plant community, though there are several pointers that assembly rules have some impact on community structure.

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Section: Discussionsupporting

confidence: 76%

Community structure and assembly rules in a dune slack: Variance in richness, guild proportionality, biomass constancy and dominance/diversity relations

Wilson

Gitay

1995

Vegetatio

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“…While this may be enough to identify the major forest types, and indeed some studies in tropical forests do confirmed a positive correlation between the richness of the woody component of a forest and its accompanying non-woody component (e.g. Webb et al 1967), there is also evidence that this is not a consistent pattern (Duivenvoorden and Lips 1995 in Colombia;ter Steege et al 2000b in Guyana;Williams-Linera et al 2005 in Mexico; Tchouto et al 2006 in Cameroon). Our own data indicate that there is no consistent correlation between tree species richness and the other life-forms studied at Los Volcanes.…”

Section: Los Volcanes Plots In a Neotropical Contextmentioning

confidence: 99%

Non-woody life-form contribution to vascular plant species richness in a tropical American forest

et al. 2008

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We provide total vascular plant species counts for three 1-ha plots in deciduous, semi-deciduous and evergreen forests in central Bolivia. Species richness ranged from 297 species and 22,360 individuals/ha in the dry deciduous forest to 382 species and 31,670 individuals/ha in the evergreen forest. Orchidaceae, Pteridophyta and Leguminosae were among the most species-rich major plant groups in each plot, and Peperomia (Piperaceae), Pleurothallis (Orchidaceae) and Tillandsia (Bromeliaceae), all epiphytes, were the most species-rich genera. This dominance of a few but very diverse and/or widespread taxa contrasted with the low compositional similarity between plots. In a neotropical context, these Central Bolivian forest plots are similar in total species richness to other dry deciduous and humid montane forests, but less rich than most Amazonian forests. Nevertheless, lianas, terrestrial herbs and especially epiphytes proved to be of equal or higher species richness than most other neotropical forest inventories from which data are available. We therefore highlight the importance of non-woody life-forms (especially epiphytes and terrestrial herbs) in Andean foothill forest ecosystems in terms of species richness and numbers of individuals, representing in some cases nearly 50% of the species and more than 75% of the individuals. These figures stress the need for an increased inventory effort on non-woody plant groups in order to accurately direct conservation actions. Abstract We provide total vascular plant species counts for three 1-ha plots in deciduous, semideciduous and evergreen forests in central Bolivia. Species richness ranged from 297 species and 22,360 individuals/ha in the dry deciduous forest to 382 species and 31,670 individuals/ha in the evergreen forest. Orchidaceae, Pteridophyta and Leguminosae were among the most species-rich major plant groups in each plot, and Peperomia (Piperaceae), Pleurothallis (Orchidaceae) and Tillandsia (Bromeliaceae), all epiphytes, were the most species-rich genera. This dominance of a few but very diverse and/or widespread taxa contrasted with the low compositional similarity between plots. In a neotropical context, these Central Bolivian forest plots are similar in total species richness to other dry 123Plant Ecol (2009) 201:87-99 DOI 10.1007 deciduous and humid montane forests, but less rich than most Amazonian forests. Nevertheless, lianas, terrestrial herbs and especially epiphytes proved to be of equal or higher species richness than most other neotropical forest inventories from which data are available. We therefore highlight the importance of non-woody life-forms (especially epiphytes and terrestrial herbs) in Andean foothill forest ecosystems in terms of species richness and numbers of individuals, representing in some cases nearly 50% of the species and more than 75% of the individuals. These figures stress the need for an increased inventory effort on non-woody plant groups in order to accurately direct conservation actions.

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“…Although it has been assumed that these reflect changes in the vegetation as a whole, it is comforting that Webb et al (1967) have concluded, in their classiflcation of complex rain forest communities, that 'the big-tree species carry the whole of the classificatory information'. Furthermore, because the big-tree species 'are directly exposed to the impact of the macro-climate (they) may be expected to reflect diflerences in site factors which are primarily climatic and largely independent of the remainder of the vegetation.…”

Section: Pollen Sources Transport and Depositionmentioning

confidence: 99%

A Pollen Diagram From Quincan Crater, North‐east Queensland, Australia

Kershaw

1971

New Phytologist

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Summary Pollen analytical results from the organic sediments of Quincan Crater broadly confirm the sequence of vegetation changes indicated in a previous study at Lake Euramoo. Only the later stage of the transition from sclerophyll vegetation to ‘warm temperate’ rain forest, culminating about 6000 B.P., is represented at Quincan, but indicates that the change was most probably due to an increase in effective precipitation. Afterwards rain forest remained the principal vegetation type for 3000 or 4000 years but changed from the initial ‘warm temperate’ to a ‘subtropical’ kind probably as a result of an increase in temperature and possibly also of precipitation. At about 2000 B.P. the ‘subtropical’ rain forest assumed a ‘drier’ facies and there was a partial readvance of the sclerophyll vegetation.

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Studies in the Numerical Analysis of Complex Rain-Forest Communities: II. The Problem of Species-Sampling

Cited by 78 publications

References 7 publications

Community structure and assembly rules in a dune slack: Variance in richness, guild proportionality, biomass constancy and dominance/diversity relations

Community structure and assembly rules in a dune slack: Variance in richness, guild proportionality, biomass constancy and dominance/diversity relations

Non-woody life-form contribution to vascular plant species richness in a tropical American forest

A Pollen Diagram From Quincan Crater, North‐east Queensland, Australia

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