Variation in biotic interactions mediates the effects of masting and rainfall fluctuations on seedling demography in a subtropical rainforest

AbstractThe aim of this review is to summarize the literature knowledge about how abiotic environmental factors and biotic interactions affect the sequentially overlapping longitudinal distribution of Central European species of the net-spinning freshwater caddisfly larvae of the genus Hydropsyche (Trichoptera: Hydropsychidae). In this relation, several physical and chemical parameters of water are discussed, as well as different species-specific traits, behavioural aspects and the interaction of coexisting species. Longitudinal gradients of river networks, especially annual temperature range, flow velocity and the particle size of suspended food material play a crucial role in forming the downstream succession of characteristic species, while increased levels of organic pollution, nutrients, salinity and heavy metals facilitates the presence of more tolerant ones. Several species-specific traits, such as respiration range, net-building frequency, head capsule size or optimal net-building velocity correlate with the position of a given species in the sequence. Coexistence of species with similar ecological demands in the overlapping zones of distribution is facilitated by differences in feeding and net-building habits, microhabitat preferences and staggering life cycles, but complicated at the same time by means of inter- and intraspecific territorial behaviour, such as fighting for the ownership of larval retreats or the practice of stridulation.

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Demographic effects of interacting species: exploring stable coexistence under increased climatic variability in a semiarid shrub community

Scientific Reports ◽

10.1038/s41598-021-82571-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ana I. García-Cervigón ◽

Pedro F. Quintana-Ascencio ◽

Adrián Escudero ◽

Merari E. Ferrer-Cervantes ◽

Ana M. Sánchez ◽

...

Keyword(s):

Population Dynamics ◽

Species Coexistence ◽

Climatic Factors ◽

Demographic Data ◽

Climatic Variability ◽

Biotic Interactions ◽

Vital Rates ◽

Climatic Fluctuations ◽

Demographic Models ◽

Shrub Community

AbstractPopulation persistence is strongly determined by climatic variability. Changes in the patterns of climatic events linked to global warming may alter population dynamics, but their effects may be strongly modulated by biotic interactions. Plant populations interact with each other in such a way that responses to climate of a single population may impact the dynamics of the whole community. In this study, we assess how climate variability affects persistence and coexistence of two dominant plant species in a semiarid shrub community on gypsum soils. We use 9 years of demographic data to parameterize demographic models and to simulate population dynamics under different climatic and ecological scenarios. We observe that populations of both coexisting species may respond to common climatic fluctuations both similarly and in idiosyncratic ways, depending on the yearly combination of climatic factors. Biotic interactions (both within and among species) modulate some of their vital rates, but their effects on population dynamics highly depend on climatic fluctuations. Our results indicate that increased levels of climatic variability may alter interspecific relationships. These alterations might potentially affect species coexistence, disrupting competitive hierarchies and ultimately leading to abrupt changes in community composition.

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Nitric oxide signalling in plant interactions with pathogenic fungi and oomycetes

Journal of Experimental Botany ◽

10.1093/jxb/eraa596 ◽

2020 ◽

Author(s):

Tereza Jedelská ◽

Lenka Luhová ◽

Marek Petřivalský

Keyword(s):

Nitric Oxide ◽

Current Knowledge ◽

Biotic Interactions ◽

Decisive Role ◽

Pathogenic Fungi ◽

Plant Colonization ◽

No Production ◽

Plant Interactions ◽

Oriented Growth ◽

Plant Pathogen Interactions

Abstract Nitric oxide (NO) and reactive nitrogen species have emerged as crucial signalling and regulatory molecules across all organisms. In plants, fungi and fungi-like oomycetes, NO is involved in the regulation of multiple processes during their growth, development, reproduction, responses to the external environment and biotic interactions. It has become evident that NO is produced and used as signalling and defence cues by both partners in multiple forms of plant interactions with their microbial counterparts, ranging from symbiotic to pathogenic modes. This review summarizes current knowledge on NO role in plant-pathogen interactions, focused on biotrophic, necrotrophic and hemibiotrophic fungi and oomycetes. Actual advances and gaps in the identification of NO sources and fate in plant and pathogen cells are discussed. We review the decisive role of time- and site-specific NO production in germination, oriented growth and active penetration of filamentous pathogens to the host tissues, as well in pathogen recognition, and defence activation in plants. Distinct functions of NO are highlighted on diverse interactions of host plants with fungal and oomycete pathogens of different lifestyles, where NO in interplay with reactive oxygen species govern successful plant colonization, cell death and resistance establishment.

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