Plant diversity increases with the strength of negative density dependence at the global scale

Science ◽  
2017 ◽  
Vol 356 (6345) ◽  
pp. 1389-1392 ◽  
Author(s):  
Joseph A. LaManna ◽  
Scott A. Mangan ◽  
Alfonso Alonso ◽  
Norman A. Bourg ◽  
Warren Y. Brockelman ◽  
...  
Keyword(s):  
Species Diversity ◽  
Density Dependence ◽  
Rare Species ◽  
Species Abundance ◽  
Biotic Interactions ◽  
Global Scale ◽  
Latitudinal Shift ◽  
Negative Density Dependence ◽  
The Tropics ◽  
The Relationship

Theory predicts that higher biodiversity in the tropics is maintained by specialized interactions among plants and their natural enemies that result in conspecific negative density dependence (CNDD). By using more than 3000 species and nearly 2.4 million trees across 24 forest plots worldwide, we show that global patterns in tree species diversity reflect not only stronger CNDD at tropical versus temperate latitudes but also a latitudinal shift in the relationship between CNDD and species abundance. CNDD was stronger for rare species at tropical versus temperate latitudes, potentially causing the persistence of greater numbers of rare species in the tropics. Our study reveals fundamental differences in the nature of local-scale biotic interactions that contribute to the maintenance of species diversity across temperate and tropical communities.

scholarly journals Contribution of conspecific negative density dependence to species diversity is increasing towards low environmental limitation in Japanese forests

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pavel Fibich ◽  
Masae I. Ishihara ◽  
Satoshi N. Suzuki ◽  
Jiří Doležal ◽  
Jan Altman
Keyword(s):  
Species Diversity ◽  
Density Dependence ◽  
Snow Depth ◽  
Biotic Interactions ◽  
Species Number ◽  
Japanese Archipelago ◽  
High Species Diversity ◽  
Negative Density Dependence ◽  
The Japanese Archipelago ◽  
Depth Gradients

AbstractSpecies coexistence is a result of biotic interactions, environmental and historical conditions. The Janzen-Connell hypothesis assumes that conspecific negative density dependence (CNDD) is one of the local processes maintaining high species diversity by decreasing population growth rates at high densities. However, the contribution of CNDD to species richness variation across environmental gradients remains unclear. In 32 large forest plots all over the Japanese archipelago covering > 40,000 individual trees of > 300 species and based on size distributions, we analysed the strength of CNDD of individual species and its contribution to species number and diversity across altitude, mean annual temperature, mean annual precipitation and maximum snow depth gradients. The strength of CNDD was increasing towards low altitudes and high tree species number and diversity. The effect of CNDD on species number was changing across altitude, temperature and snow depth gradients and their combined effects contributed 11–18% of the overall explained variance. Our results suggest that CNDD can work as a mechanism structuring forest communities in the Japanese archipelago. Strong CNDD was observed to be connected with high species diversity under low environmental limitations where local biotic interactions are expected to be stronger than in niche-based community assemblies under high environmental filtering.

scholarly journals Ocean currents promote rare species diversity in protists

2020 ◽  
Vol 6 (29) ◽  
pp. eaaz9037
Author(s):  
Paula Villa Martín ◽  
Aleš Buček ◽  
Thomas Bourguignon ◽  
Simone Pigolotti
Keyword(s):  
Species Diversity ◽  
Power Law ◽  
Rare Species ◽  
Species Abundance ◽  
Ecological Factors ◽  
Abundant Species ◽  
Chaotic Advection ◽  
Power Law Decay ◽  
Aquatic Microbes ◽  
Oceanic Currents

Oceans host communities of plankton composed of relatively few abundant species and many rare species. The number of rare protist species in these communities, as estimated in metagenomic studies, decays as a steep power law of their abundance. The ecological factors at the origin of this pattern remain elusive. We propose that chaotic advection by oceanic currents affects biodiversity patterns of rare species. To test this hypothesis, we introduce a spatially explicit coalescence model that reconstructs the species diversity of a sample of water. Our model predicts, in the presence of chaotic advection, a steeper power law decay of the species abundance distribution and a steeper increase of the number of observed species with sample size. A comparison of metagenomic studies of planktonic protist communities in oceans and in lakes quantitatively confirms our prediction. Our results support that oceanic currents positively affect the diversity of rare aquatic microbes.

Water temperature influencing dactylogyrid species communities in roach, Rutilus rutilus, in the Czech Republic

2001 ◽  
Vol 75 (4) ◽  
pp. 373-383 ◽  
Author(s):  
A. Šimková ◽  
P. Sasal ◽  
D. Kadlec ◽  
M. Gelnar
Keyword(s):  
Czech Republic ◽  
Water Temperature ◽  
Rare Species ◽  
Interspecific Interactions ◽  
Species Abundance ◽  
Rutilus Rutilus ◽  
Roach Rutilus Rutilus ◽  
Effect Of Water ◽  
Morava River ◽  
The Relationship

Dactylogyrid species (Monogenea) communities were studied in roach, Rutilus rutilus, collected from two localities in the basin of Morava river, Czech Republic, during the period from April to November 1997 and March to September 1998 to determine the effect of water temperature on parasite abundance, species richness and diversity. Dactylogyrid species were found to co-occur on the gills of roach with up to six species found on the same host individual. Nine dactylogyrid species were identified with the abundance of each reaching a very low level. Niche size was considered to increase with species abundance even when water temperature was high. There was a strong effect of water temperature on abundance of the common dactylogyrid species (D. crucifer, D. nanus, D. rutili and D. suecicus) as well as of the rare species D. rarissimus. The temporary occurrence of the rare species was found without any temperature effect. Water temperature did not affect the relationship between abundance and niche size. Niche size increased with abundance, even when the water temperature was high, which suggests that negative interspecific interactions are not important within dactylogyrid communities.

scholarly journals Response to Comment on “Plant diversity increases with the strength of negative density dependence at the global scale”

Science ◽  
2018 ◽  
Vol 360 (6391) ◽  
pp. eaar5245 ◽  
Author(s):  
Joseph A. LaManna ◽  
Scott A. Mangan ◽  
Alfonso Alonso ◽  
Norman A. Bourg ◽  
Warren Y. Brockelman ◽  
...  
Keyword(s):  
Density Dependence ◽  
Plant Diversity ◽  
Global Scale ◽  
Negative Density Dependence

scholarly journals Conspecific negative density dependence decreases with increasing species abundance

Ecosphere ◽  
2015 ◽  
Vol 6 (12) ◽  
pp. art257 ◽  
Author(s):  
Meng Xu ◽  
Yongfan Wang ◽  
Shixiao Yu
Keyword(s):  
Density Dependence ◽  
Species Abundance ◽  
Negative Density Dependence

Species abundance is jointly determined by functional traits and negative density dependence in a subtropical forest in southern China

2021 ◽  
Author(s):  
Weitao Wang ◽  
Yun Jiang ◽  
Buhang Li ◽  
Nianxun Xi ◽  
Yongfa Chen ◽  
...  
Keyword(s):  
Density Dependence ◽  
Leaf Area ◽  
Functional Traits ◽  
Southern China ◽  
Species Abundance ◽  
Plant Functional Traits ◽  
Equation Modeling ◽  
Dry Matter Content ◽  
Combined Effects ◽  
Negative Density Dependence

Abstract Aims The factors affecting species abundance are a subject of ongoing debates in community ecology. Empirical studies have demonstrated that tree abundance is affected by plant functional traits and negative density dependence (NDD). However, few studies have focused on the combined effects of negative density dependence and plant functional traits on species abundance. Methods In this study, we used tree functional traits and two census data from a 50-ha forest dynamic plot in the Heishiding (HSD) Nature Reserve to explore the combined effects of functional traits and NDD on species abundance. Using hierarchical Bayesian models, we analyzed how neighbor densities affected the survival of saplings from 130 species and extracted posterior means of the coefficients to represent NDD. The structural equation modeling (SEM) analysis was then applied to investigate the causal relationships among species functional traits, negative density dependence, and species abundance. Important findings SEM showed that tree functional traits, including specific leaf area (SLA), leaf area (LA), leaf dry matter content (LDMC), leaf N content (LNC), maximum electron transport rate (ETRmax), and conspecific adult negative density dependence (CNDDadult), together explained 20% of the total variation in tree abundance. Specifically, SLA affected tree abundance both directly and indirectly via CNDDadult, with a totally negative influence on abundance. LDMC and LNC had only indirect effects mediated by CNDDadult on tree abundance. ETRmax and LA had directly negative effects on abundance, but their direct connections with CNDDadult were not observed. In addition, CNDDadult was negatively correlated with species abundance, indicating that abundant species are under stronger negative density dependence. Among these investigated traits, SLA contributed the most to the variation in CNDDadult and abundance. We argued that our findings of trait-CNDDadult-abundance relationships can improve our understanding of the determinants of species commonness and rarity in forests.

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