• Clonal growth of plants is attained by a number of morphologically different organs (e.g. stolons, rhizomes, and roots), which are not functionally equivalent. Consequently, these clonal growth ...organ (CGO) types can determine functional traits that are associated with clonality, although little is known about their evolutionary flexibility or the constraining role they play on clonal traits.
• We investigated the rates of evolutionary change by which individual CGOs are acquired and lost using a set of 2652 species of Central European flora. Furthermore, we asked how these individual CGOs constrain functionally relevant clonal traits, such as lateral spread, number of offspring, and persistence of connections.
• We show that plants can easily switch in evolution among individual types of CGO and between clonal and nonclonal habits. However, not all these transitions are equally probable. Namely, stem-based clonal growth and root-based clonal growth constitute evolutionarily separate forms of clonal growth.
• Clonal traits are strongly constrained by individual CGO types. Specifically, fast lateral spread is attained by stolons or hypogeogenous rhizomes, and persistent connections are attained by all rhizome types. However, the ease with which clonal organs appear and disappear in evolution implies that plants can overcome these constraints by adjusting their morphologies.
Below-ground bud banks have experienced much recent interest due to discoveries that they (1) account for the majority of seasonal population renewal in many communities, (2) are crucial to ...regeneration following disturbance, and (3) have important consequences for plant population dynamics and plant and ecosystem function across a number of habitats.
This review presents an overview of the role of bud banks in plant population renewal, examines bud bank life history, summarizes bud bank traits and their potential ecological implications, synthesizes the response of bud banks to disturbance, and highlights gaps to guide future research. The characteristics and life history of buds, including their natality, dormancy, protection and longevity, provide a useful framework for advancing our understanding of bud banks. The fate of buds depends on their age, size, type, location, and biotic and abiotic factors that collectively regulate bud bank dynamics. A bud bank can provide a demographic storage effect stabilizing population dynamics, and also confer resistance to disturbance and invasion. Regeneration capacity following disturbance is determined by interactions among the rates of bud natality, depletion and dormancy (meristem limitation), and the resources available to support the regeneration process. The resulting response of plants and their bud banks to disturbances such as fire, herbivory and anthropogenic sources determines the community's regenerative capacity.
Vegetation responses to environmental change may be mediated through changes in bud bank dynamics and phenology. Environmental change that depletes the bud bank or prohibits its formation likely results in a loss of vegetation resilience and plant species diversity. Standardization of bud sampling, examination of bud banks in more ecosystems and their response to environmental variation and disturbance regimes, employment of stage-structured bud bank modelling and evaluation of the cost of bud bank construction and maintenance will benefit this expanding field of research.
In recent years, belowground plant ecology has experienced a booming interest. This has resulted in major advances towards a greater understanding of belowground plant and ecosystem functioning ...focused on fine roots, mycorrhizal associations and nutrient acquisition.
Despite this, other important functions (e.g., on‐spot persistence, space occupancy, resprouting after biomass removal) exerted by different belowground plant organs (e.g., roots, rhizomes, bulbs) remain largely unexplored.
Here, we propose a framework providing a comprehensive perspective on the entire set of belowground plant organs and functions. We suggest a compartment‐based approach. We identify two major belowground compartments, that is, acquisitive and nonacquisitive, associated with biomass allocation into these functions. Also, we recommend the nonacquisitive compartment to be divided into structural (e.g., functional roles carried out by rhizomes, such as sharing of resources, space occupancy) and nonstructural (e.g., functional roles exerted by carbohydrates reserve affecting resprouting ability, protection against climate adversity) subcompartments. We discuss methodological challenges—and their possible solutions—posed by changes in biomass allocation across growth forms and ontogenetic stages, and in relation to biomass partitioning and turnover.
We urge the implementation of methods and approaches considering all the belowground plant compartments. This way, we would make sure that key, yet less‐studied functions would be incorporated into the belowground plant ecology research agenda. The framework has potential to advance the understanding of belowground plant and ecosystem functioning by considering relations and trade‐offs between different plant functions and organs. At last, we identify four major areas where using the proposed compartment‐based approach would be particularly important, namely (a) biomass scaling, (b) clonality‐resource acquisition relations, (c) linkages between resprouting and changing environmental conditions and (d) carbon sequestration.
A plain language summary is available for this article.
Plain Language Summary
Foreign Language Funkční ekologie podzemních částí rostlinSummary in Czech
V posledních letech zažívá ekologie podzemních částí rostlin velký zájem výzkumníků po celém světě. Tento zájem přispěl k lepšímu porozumění funkce podzemních částí rostlin, zejména jemných kořenů a mykorhizy, které hrají významnou roli při získávání vody a živin. Jiné důležité funkce rostlin, jako je přežívání na daném místě, obsazování prostoru, nebo schopnost regenerace po poškození těla, zprostředkované například zásobními kořeny a oddenky, však zůstávají opomíjeny. S cílem napravit tuto situaci, navrhujeme integrovaný přístup, který umožní komplexnější pohled na celou řadu podzemních rostlinných orgánů a jejich funkcí. Na příkladech z literatury ukazujeme, jak zaměření pouze na jemné kořeny může omezit naši schopnost poznat ekologii rostlin. Navrhujeme přístup založený na rozlišení základních funkčních specializací podzemních orgánů. Identifikujeme dva hlavní funkční podzemní kompartmenty, za prvé akviziční, tj. podílející se na získávání vody a živin, a za druhé neakviziční, tj. podílející se na propojování různých částí rostliny, na klonálním růstu a na regeneraci po narušení. Diskutujeme metodologické problémy spojené s implementací tohoto přístupu a o jejich možných řešeních. Přestavujeme rozdíly v investicích do těchto podzemních kompartmentů u různých růstových forem a během života rostliny, stejně tak problémy související se stanovením biomasy a jejím obratem. Závěrem vyzýváme výzkumníky, aby při studium ekologie aplikovali metody a přístupy, které berou v úvahu všechny podzemní orgány rostlin. Pouze tímto způsobem zajistíme, aby méně studované, avšak zcela klíčové funkce podzemních orgánů rostlin, byly začleněny do výzkumného plánu funkčních ekologů. Příkladem může být jejich využití pro lepší odhad sekvestrace uhlíku v podzemních orgánech rostlin, což je důležité pro tvorbu celosvětových geochemických modelů.
Clonal growth of plants is mainly a result of the vegetative growth of organs hidden beneath the soil surface and producing potentially independent vegetative offspring. Clonal traits are difficult ...to measure due to inaccessibility of the space they inhabit and their morphological diversity. This causes great difficulties with descriptions, standardization of measurements across plant growth forms and, probably, a lack of appropriate questions that should be answered using them. The freely available CLO-PLA database (http://clopla.butbn.cas.cz/) can help to assess the roles of vegetative means of regeneration and spread in plant communities under the effect of various biotic and abiotic filters. It can serve as a source of reference on persistence traits of European temperate flora and, eventually, as a guide for trait sampling in other regions of the world.
Polyploidy is arguably the single most important genetic mechanism in plant speciation and diversification. It has been repeatedly suggested that polyploids show higher vegetative reproduction than ...diploids (to by-pass low fertility after the polyploidization), but there are no rigorous tests of it.
Data were analysed by phylogenetic regressions of clonal growth parameters, and vegetative reproduction in culture on the ploidy status of a large set of species (approx. 900) from the Central European Angiosperm flora. Further, correlated evolution of ploidy and clonal traits was examined to determine whether or not polyploidy precedes vegetative reproduction.
The analyses showed that polyploidy is strongly associated with vegetative reproduction, whereas diploids rely more on seed reproduction. The rate of polyploid speciation is strongly enhanced by the existence of vegetative reproduction (namely extensive lateral spread), whereas the converse is not true.
These findings confirm the old hypothesis that polyploids can rely on vegetative reproduction which thus may save many incipient polyploids from extinction. A closer analysis also shows that the sequence of events begins with development of vegetative reproduction, which is then followed by polyploidy. Vegetative reproduction is thus likely to play an important role in polyploid speciation.
Background and aims
Nutrient allocation and scaling affect plant strategy and metabolism but this information is rarely incorporated into fundamental ecological frameworks. One important question is ...whether plants with a different ecological strategy share the same nutrient allocation patterns.
Methods
Here, we tested scaling between nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) concentrations in aboveground tissues of 130 co-occurring Central European grassland species, and examined whether scaling is consistent within the competitor, stress-tolerator, ruderal (CSR) framework.
Results
Tissue element-element relationships were typically isometric (1:1 ratio). However, we observed a few anisometries: K accelerated with N (5:4 ratio), and the scaling of the combined suites of elements (N x P and K x Ca x Mg) deviated from isometry with a 3:4 ratio. We observed no N-Ca and P-Ca relationship. Scaling coefficients and normalisation constants were mostly consistent regardless of plant height or CSR strategy. However, N-Ca and Ca-Mg scaling was apparent only in less competitive species (C scores below median) and for P-K scaling, the normalisation constant was almost twice as high in ruderals than in less ruderal species.
Conclusion
Consistent and proportional nutrient allocation patterns in co-occurring species with different CSR strategies suggest dominant influence of common rules governing nutrient uptake and utilisation in temperate herbs. Tissue Ca could be an exception because its allocation with respect to N and Mg changes along the competitive spectrum, possibly reflecting the role of Ca in cell wall stability and integrity.
Plants possess a large variety of nonacquisitive belowground organs, such as rhizomes, tubers, bulbs, and coarse roots. These organs determine a whole set of functions that are decisive in coping ...with climate, productivity, disturbance, and biotic interactions, and have been hypothesized to affect plant distribution along environmental gradients. We assembled data on belowground organ morphology for 1712 species from Central Europe and tested these hypotheses by quantifying relationships between belowground morphologies and species optima along ecological gradients related to productivity and disturbance. Furthermore, we linked these data with species co-occurrence in 30 115 vegetation plots from the Czech Republic to determine relationships between belowground organ diversity and these gradients. The strongest gradients determining belowground organ distribution were disturbance severity and frequency, light, and moisture. Nonclonal perennials and annuals occupy much smaller parts of the total environmental space than major types of clonal plants. Forest habitats had the highest diversity of co-occurring belowground morphologies; in other habitats, the diversity of belowground morphologies was generally lower than the random expectation. Our work shows that nonacquisitive belowground organs may be partly responsible for plant environmental niches. This adds a new dimension to the plant trait spectrum, currently based on acquisitive traits (leaves and fine roots) only.
Clonal plants have more traits enabling individual persistence (larger belowground storage of buds and assimilates), whereas non-clonal plants have more traits enabling population persistence (a ...higher reliance on regeneration from seeds). This difference presumably makes those groups respond differently to disturbance. We asked whether this difference is already expressed in the first year of the plant’s life. In a pot experiment with 17 congeneric pairs of clonal and non-clonal herbs, we investigated response to a disturbance at the individual level. We were interested whether the leaf C/N ratio (a proxy reflecting active growth and photosynthetic efficiency), the R/S ratio (a proxy for belowground storage) and the amount of compensated biomass differ between clonal and non-clonal herbs. Moreover, we asked whether compensation for the loss of aboveground biomass after disturbance can be predicted by the R/S ratio or explained by the leaf C/N ratio. We found that clonal herbs have higher leaf C/N and R/S ratios than non-clonal herbs. Under disturbance, the leaf C/N and R/S ratios decreased in the clonal herbs and increased in the non-clonal herbs. However, the clonal and non-clonal plants did not differ in biomass compensation ability. Neither the R/S ratio nor the leaf C/N ratio explained the compensation abilities of the herbs. These results show that even though the growth strategies of clonal and non-clonal plants and their reactions to disturbance are different, the groups are similarly capable of compensating for the loss of aboveground biomass. Clonal plants do not have an advantage over non-clonal plants under disturbance during their first year of life.
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