scholarly journals Are we missing the forest for the trees? Conspecific negative density dependence in a temperate deciduous forest

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0245639
Author(s):  
Kathryn E. Barry ◽  
Stefan A. Schnitzer
Keyword(s):  
Life History ◽  
Density Dependence ◽  
Plant Community ◽  
Woody Plant ◽  
Woody Species ◽  
Community Level ◽  
Life History Strategies ◽  
Point Pattern ◽  
Dispersal Syndromes ◽  
Negative Density Dependence

One of the central goals of ecology is to determine the mechanisms that enable coexistence among species. Evidence is accruing that conspecific negative density dependence (CNDD), the process by which plant seedlings are unable to survive in the area surrounding adults of their same species, is a major contributor to tree species coexistence. However, for CNDD to maintain community-level diversity, three conditions must be met. First, CNDD must maintain diversity for the majority of the woody plant community (rather than merely specific groups). Second, the pattern of repelled recruitment must increase in with plant size. Third, CNDD should extend to the majority of plant life history strategies. These three conditions are rarely tested simultaneously. In this study, we simultaneously test all three conditions in a woody plant community in a North American temperate forest. We examined whether understory and canopy woody species across height categories and dispersal syndromes were overdispersed–a spatial pattern indicative of CNDD–using spatial point pattern analysis across life history stages and strategies. We found that there was a strong signal of overdispersal at the community level. Across the whole community, larger individuals were more overdispersed than smaller individuals. The overdispersion of large individuals, however, was driven by canopy trees. By contrast, understory woody species were not overdispersed as adults. This finding indicates that the focus on trees for the vast majority of CNDD studies may have biased the perception of the prevalence of CNDD as a dominant mechanism that maintains community-level diversity when, according to our data, CNDD may be restricted largely to trees.

scholarly journals Are we missing the forest for the trees? Conspecific negative density dependence in a temperate deciduous forest

2021 ◽  
Author(s):  
Kathryn E. Barry ◽  
Stefan A. Schnitzer
Keyword(s):  
Life History ◽  
Density Dependence ◽  
Plant Community ◽  
Plant Diversity ◽  
Temperate Forest ◽  
Woody Plant ◽  
Community Level ◽  
Life History Strategies ◽  
Canopy Trees ◽  
Negative Density Dependence

AbstractOne of the central goals of ecology is to determine the mechanisms that enable coexistence among species. Evidence is accruing that conspecific negative density dependence (CNDD), the process by which plant seedlings are unable to survive in the area surrounding adults of their same species, is a major contributor to tree species coexistence. However, for CNDD to maintain diversity, three conditions must be met. First, CNDD must maintain diversity for the majority of the woody plant community (rather than merely specific groups). Second, the pattern of repelled recruitment must increase in with plant size. Third, CNDD must occurs across life history strategies and not be restricted to a single life history strategy. These three conditions are rarely tested simultaneously. In this study, we simultaneously test all three conditions in a woody plant community in a North American temperate forest. We examined whether the different woody plant growth forms (shrubs, understory trees, mid-story trees, canopy trees, and lianas) at different ontogenetic stages (seedling, sapling, and adult) were overdispersed – a spatial pattern indicative of CNDD – using spatial point pattern analysis across life history stages and strategies. We found that there was a strong signal of overdispersal at the community level. However, this pattern was driven by adult canopy trees. By contrast, understory plants, which can constitute up to 80% of temperate forest plant diversity, were not overdispersed as adults. The lack of overdispersal suggests that CNDD is unlikely to be a major mechanism maintaining understory plant diversity. The focus on trees for the vast majority of CNDD studies may have biased the perception of the prevalence of CNDD as a dominant mechanism that maintains community-level diversity when, according to our data, CNDD may be restricted largely to trees.

A structural gradient in cerrado vegetation of Brazil: changes in woody plant density, species richness, life history and plant composition

2002 ◽  
Vol 18 (5) ◽  
pp. 775-794 ◽  
Author(s):  
Luci Ferreira Ribeiro ◽  
Marcelo Tabarelli
Keyword(s):  
Life History ◽  
Species Richness ◽  
Species Composition ◽  
Woody Plant ◽  
Plant Density ◽  
Lower Layer ◽  
Sensu Stricto ◽  
Life History Strategies ◽  
Cerrado Vegetation ◽  
Structural Types

Four structural types of cerrado vegetation were examined to test the following hypotheses: (1) there are predictable changes in woody plant density, species richness and life-history strategies from one structural type to another; and (2) plant species composition in the less-rich structural types represent particular and impoverished subsets of those found in the richer ones. The study was conducted at Fazenda Palmares (5°33′S, 42°37′W) Piauí State, Brazil. A 47% decrease in woody plant density between cerradão (forest) and the least-dense type of cerrado sensu stricto (scrub) was associated with a 40% decrease in species richness. The percentage of lower-layer species was reduced by 29% in the least dense type of cerrado sensu stricto compared to cerradão. The proportion of species that flower and fruit during the rainy season was also reduced by one third. Species were not distributed as impoverished subsets along the cerradão–cerrado sensu stricto gradient. It is argued that the reduction in woody plant density and richness is partly due to factors limiting the occurrence of species with particular life-history strategies. The species composition of structural types is affected by the ‘mass effect’ and also by surrounding biotas, which provide species that colonize particular types of cerrado vegetation. Both these processes reduce the likelihood that the species composition in the poorer structural types are simple subsets of those present in the richer types.

scholarly journals Rasgos morfológicos regenerativos en una comunidad de especies leñosas en un bosque seco tropical tumbesino

2016 ◽  
Vol 64 (2) ◽  
pp. 859 ◽  
Author(s):  
José Miguel Romero Saritama ◽  
César Pérez-Rúiz
Keyword(s):  
Plant Species ◽  
Morphological Traits ◽  
Woody Plant ◽  
Seed Mass ◽  
Woody Species ◽  
Dry Forest ◽  
Community Level ◽  
Tropical Dry Forests ◽  
Dry Forests ◽  
Woody Plant Species

The study of functional morphological traits enables us to know fundamental aspects of the dynamics of plant communities in local and global habitats. Regenerative morphological traits play an important role in defining plant history and ecological behavior. Seed and fruit characteristics determine to a large extent the patterns for dispersal, germination, establishment and seedling recruitment a given species exhibits on its natural habitat. Despite their prominent role, seed and fruit traits have been poorly studied at the community level of woody plant species in neo-tropical dry forests. In the present study we aimed at i) evaluate the functional role of morphological traits of seeds, fruits and embryo in woody plant species; ii) determine which are the morphological patterns present in seeds collected from the community of woody species that occur in neo-tropical dry forests; and iii) compare woody plant species seed mass values comparatively between neo-tropical dry and tropical forests. To do so, mature seeds were collected from 79 plant species that occur in the Tumbesian forest of Southwest Ecuador. The studied species included the 42 and 37 most representative tree and shrubbery species of the Tumbesian forest respectively. A total of 18 morphological traits (seven quantitative and 11 qualitative) were measured and evaluated in the seeds, fruits and embryos of the selected species, and we compared the seeds mass with other forest types. Our results showed a huge heterogeneity among traits values in the studied species. Seed mass, volume and number were the traits that vary the most at the community level, i.e. seed length ranged from 1.3 to 39 mm, and seed width from 0.6 to 25 mm. Only six embryo types were found among the 79 plant species. In 40 % of the cases, fully developed inverted embryos with large and thick cotyledons to store considerable amount of nutrients were recorded. We concluded that highly variable and functionally complementary morphological traits occur among the studied woody plants of the dry Tumbesian forest. The latter favors a plethora of behavioral mechanisms to coexist among woody species of the dry forest in response to the environmental stress that is typical of arid areas.

scholarly journals Evidence for dispersal syndromes in freshwater fishes

2018 ◽  
Vol 285 (1871) ◽  
pp. 20172214 ◽  
Author(s):  
Lise Comte ◽  
Julian D. Olden
Keyword(s):  
Life History ◽  
Meta Analysis ◽  
Explanatory Power ◽  
Movement Ecology ◽  
Freshwater Fishes ◽  
Life History Strategies ◽  
Freshwater Species ◽  
Ecological Specialization ◽  
Dispersal Syndromes ◽  
Dispersal Distances

Dispersal is a fundamental process defining the distribution of organisms and has long been a topic of inquiry in ecology and evolution. Emerging research points to an interdependency of dispersal with a diverse suite of traits in terrestrial organisms, however the extent to which such dispersal syndromes exist in freshwater species remains uncertain. Here, we test whether dispersal in freshwater fishes (1) is a fixed property of species, and (2) correlates with life-history, morphological, ecological and behavioural traits, using a global dataset of dispersal distances collected from the literature encompassing 116 riverine species and 196 locations. Our meta-analysis revealed a high degree of repeatability and heritability in the dispersal estimates and strong associations with traits related to life-history strategies, energy allocation to reproduction, ecological specialization and swimming skills. Together, these results demonstrate that similar to terrestrial organisms, the multi-dimensional nature of dispersal syndromes in freshwater species offer opportunities for the development of a unifying paradigm of movement ecology that transcend taxonomic and biogeographical realms. The high explanatory power of the models also suggests that trait-based and phylogenetic approaches hold considerable promises to inform conservation efforts in a rapidly changing world.

scholarly journals DENSITY DEPENDENCE IN AN ANNUAL PLANT COMMUNITY: VARIATION AMONG LIFE HISTORY STAGES

2001 ◽  
Vol 71 (3) ◽  
pp. 423-446 ◽  
Author(s):  
Deborah E. Goldberg ◽  
Roy Turkington ◽  
Linda Olsvig-Whittaker ◽  
Andrew R. Dyer
Keyword(s):  
Life History ◽  
Density Dependence ◽  
Plant Community ◽  
Annual Plant ◽  
Life History Stages ◽  
Community Variation

scholarly journals Can Functional Traits Explain Plant Coexistence? A Case Study with Tropical Lianas and Trees

Diversity ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 397
Author(s):  
Felipe N. A. Mello ◽  
Sergio Estrada-Villegas ◽  
David M. DeFilippis ◽  
Stefan A. Schnitzer
Keyword(s):  
Life History ◽  
Functional Traits ◽  
Woody Plant ◽  
Meta Analysis ◽  
Life History Strategy ◽  
Life History Strategies ◽  
Morphological And Physiological Traits ◽  
The Mean ◽  
Plant Coexistence

Organisms are adapted to their environment through a suite of anatomical, morphological, and physiological traits. These functional traits are commonly thought to determine an organism’s tolerance to environmental conditions. However, the differences in functional traits among co-occurring species, and whether trait differences mediate competition and coexistence is still poorly understood. Here we review studies comparing functional traits in two co-occurring tropical woody plant guilds, lianas and trees, to understand whether competing plant guilds differ in functional traits and how these differences may help to explain tropical woody plant coexistence. We examined 36 separate studies that compared a total of 140 different functional traits of co-occurring lianas and trees. We conducted a meta-analysis for ten of these functional traits, those that were present in at least five studies. We found that the mean trait value between lianas and trees differed significantly in four of the ten functional traits. Lianas differed from trees mainly in functional traits related to a faster resource acquisition life history strategy. However, the lack of difference in the remaining six functional traits indicates that lianas are not restricted to the fast end of the plant life–history continuum. Differences in functional traits between lianas and trees suggest these plant guilds may coexist in tropical forests by specializing in different life–history strategies, but there is still a significant overlap in the life–history strategies between these two competing guilds.

Woody Plant Traits and Life-History Strategies across Disturbance Gradients and Biome Boundaries in the Hluhluwe-iMfolozi Park

2017 ◽  
pp. 189-210 ◽  
Author(s):  
Laurence M. Kruger ◽  
Tristan Charles-Dominique ◽  
William J. Bond ◽  
Jeremy J. Midgley ◽  
Dave A. Balfour ◽  
...  
Keyword(s):  
Life History ◽  
Woody Plant ◽  
Plant Traits ◽  
Life History Strategies

Reproductive phenology of the cerrado plant community in Emas National Park (central Brazil)

2004 ◽  
Vol 52 (2) ◽  
pp. 149 ◽  
Author(s):  
Marco Antônio Batalha ◽  
Fernando Roberto Martins
Keyword(s):  
Plant Community ◽  
National Park ◽  
Vegetation Type ◽  
Woody Species ◽  
Field Trips ◽  
Reproductive Phenology ◽  
Wet Season ◽  
Central Plateau ◽  
Central Brazil ◽  
Dispersal Syndromes

The cerrado, a savanna-like formation, is the second-most widespread vegetation type in Brazil. Its core region occupies the Brazilian Central Plateau, with a seasonal climate, including wet summer and dry winter. We studied the reproductive phenological patterns of the cerrado plant community in Emas National Park (central Brazil). Monthly field trips revealed 601 species, classified, according to their dispersal syndromes, into anemo-, auto-, or zoochorous species, when they were dispersed by wind, explosion or gravity, or animals, respectively. We analysed the flowering and fruiting patterns of the community in relation to dispersal syndromes, comparing the herbaceous and the woody components. The herbaceous component was characterised by a majority of autochorous species, and the woody component, by a majority of zoochorous species. There was a striking seasonality in the community-wide pattern of flowering and fruiting, although this was different between the herbaceous and the woody components. Woody species flowered mainly during late dry and early wet seasons, whereas herbaceous species flowered especially during late wet season. In the dry season, when their diaspores can be dispersed more efficiently, the proportions of anemo- and autochorous fruiting species were higher. During the rainy season, when their fruits can be kept attractive for longer time, the number of fruiting zoochorous species reached its peak.

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