Nejvíce citovaný článek - PubMed ID 11452308
Biological invasions are a major threat to biodiversity in species-rich regions. Therefore, it is important to understand mechanisms behind the long-term establishment of non-native fish species in aquatic environments in the Neotropical region. Here, we associated fish biomass, species richness, and the proportion of non-native species (contamination and Kempton's indices) to quantify the non-native pressure over fish biodiversity in lakes and rivers of the Parana River floodplain, seasonally, from 2000 to 2017. We divided species into native and non-native assemblages sampled in spatio-temporal gradients. Temporal trends were examined using linear regressions and generalised additive models. Fish biomass in gillnets increased for both native and non-native fish species, but their Kempton indices were inversely correlated. Extinction of native species occurred locally with biotic differentiation of non-native species in lakes, rivers, and ecosystem contamination. A constant increase in fish biomass resulted in overwhelming biodiversity of non-natives at the end of the time series evaluated. Native biotic resistance to introductions was not detected in deterministic trends. The observed patterns were consistent with previous studies showing native biotic homogenisation and extinction of species in response to biological invasions, landscape fragmentation, and riverine impoundments. Increases in abundance and species richness of non-native fish were the biodiversity drivers that resulted in non-native species outweighing native species in the Parana floodplain.
Effects of plant diversity on grassland productivity, or overyielding, are found to be robust to nutrient enrichment. However, the impact of cumulative nitrogen (N) addition (total N added over time) on overyielding and its drivers are underexplored. Synthesizing data from 15 multi-year grassland biodiversity experiments with N addition, we found that N addition decreases complementarity effects and increases selection effects proportionately, resulting in no overall change in overyielding regardless of N addition rate. However, we observed a convex relationship between overyielding and cumulative N addition, driven by a shift from complementarity to selection effects. This shift suggests diminishing positive interactions and an increasing contribution of a few dominant species with increasing N accumulation. Recognizing the importance of cumulative N addition is vital for understanding its impacts on grassland overyielding, contributing essential insights for biodiversity conservation and ecosystem resilience in the face of increasing N deposition.
- MeSH
- biodiverzita MeSH
- dusík MeSH
- ekosystém * MeSH
- pastviny * MeSH
- rostliny MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- dusík MeSH
Plant diversity effects on community productivity often increase over time. Whether the strengthening of diversity effects is caused by temporal shifts in species-level overyielding (i.e., higher species-level productivity in diverse communities compared with monocultures) remains unclear. Here, using data from 65 grassland and forest biodiversity experiments, we show that the temporal strength of diversity effects at the community scale is underpinned by temporal changes in the species that yield. These temporal trends of species-level overyielding are shaped by plant ecological strategies, which can be quantitatively delimited by functional traits. In grasslands, the temporal strengthening of biodiversity effects on community productivity was associated with increasing biomass overyielding of resource-conservative species increasing over time, and with overyielding of species characterized by fast resource acquisition either decreasing or increasing. In forests, temporal trends in species overyielding differ when considering above- versus belowground resource acquisition strategies. Overyielding in stem growth decreased for species with high light capture capacity but increased for those with high soil resource acquisition capacity. Our results imply that a diversity of species with different, and potentially complementary, ecological strategies is beneficial for maintaining community productivity over time in both grassland and forest ecosystems.
- MeSH
- biodiverzita * MeSH
- biomasa MeSH
- ekosystém * MeSH
- lesy MeSH
- pastviny MeSH
- rostliny MeSH
- Publikační typ
- časopisecké články MeSH
Ever-growing human population and nutritional demands, supply chain disruptions, and advancing climate change have led to the realization that changes in diversity and system performance are intimately linked. Moreover, diversity and system performance depend on heterogeneity. Mitigating changes in system performance and promoting sustainable living conditions requires transformative decisions. Here, we introduce the heterogeneity-diversity-system performance (HDP) nexus as the conceptual basis upon which to formulate transformative decisions. We suggest that managing the heterogeneity of systems will best allow diversity to provide multiple benefits to people. Based on ecological theory, we pose that the HDP nexus is broadly applicable across systems, disciplines, and sectors, and should thus be considered in future decision making as a way to have a more sustainable global future.
- Klíčová slova
- biodiversity-ecosystem functioning, diversity, global change, heterogeneity, homogenization,
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
BACKGROUND AND AIMS: The observed positive diversity effect on ecosystem functioning has rarely been assessed in terms of intraspecific trait variability within populations. Intraspecific phenotypic variability could stem both from underlying genetic diversity and from plasticity in response to environmental cues. The latter might derive from modifications to a plant's epigenome and potentially last multiple generations in response to previous environmental conditions. We experimentally disentangled the role of genetic diversity and diversity of parental environments on population productivity, resistance against environmental fluctuations and intraspecific phenotypic variation. METHODS: A glasshouse experiment was conducted in which different types of Arabidopsis thaliana populations were established: one population type with differing levels of genetic diversity and another type, genetically identical, but with varying diversity levels of the parental environments (parents grown in the same or different environments). The latter population type was further combined, or not, with experimental demethylation to reduce the potential epigenetic diversity produced by the diversity of parental environments. Furthermore, all populations were each grown under different environmental conditions (control, fertilization and waterlogging). Mortality, productivity and trait variability were measured in each population. KEY RESULTS: Parental environments triggered phenotypic modifications in the offspring, which translated into more functionally diverse populations when offspring from parents grown under different conditions were brought together in mixtures. In general, neither the increase in genetic diversity nor the increase in diversity of parental environments had a remarkable effect on productivity or resistance to environmental fluctuations. However, when the epigenetic variation was reduced via demethylation, mixtures were less productive than monocultures (i.e. negative net diversity effect), caused by the reduction of phenotypic differences between different parental origins. CONCLUSIONS: A diversity of environmental parental origins within a population could ameliorate the negative effect of competition between coexisting individuals by increasing intraspecific phenotypic variation. A diversity of parental environments could thus have comparable effects to genetic diversity. Disentangling the effect of genetic diversity and that of parental environments appears to be an important step in understanding the effect of intraspecific trait variability on coexistence and ecosystem functioning.
- Klíčová slova
- Arabidopsis thaliana, DNA methylation, competition, epigenetic diversity, functional traits, genetic diversity, intraspecific phenotypic variability, parental effects, productivity, transgenerational effects,
- MeSH
- Arabidopsis * genetika MeSH
- biologická variabilita populace MeSH
- ekosystém MeSH
- fenotyp MeSH
- genetická variace MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Biodiversity is known to increase ecosystem functioning. However, species vary in their contributions to ecosystem processes. Here, we investigated seven ecosystem functions based on the consumption of different resources in tropical ant communities. We analysed how different species influence site-level resource consumption, and determined how each species influenced performance and stability of these functions. Based on simulated extinctions, we identified 'key species' with significant functional contributions. We then investigated which traits, such as biomass, abundance, and specialisation, characterized them, and compared trait distributions across four sites to analyse differences in functional redundancy. Only few species significantly influenced ecosystem functions. Common generalist species tended to be the most important drivers of many ecosystem functions, though several specialist species also proved to be important in this study. Moreover, species-specific ecological impacts varied across sites. In addition, we found that functional redundancy varied across sites, and was highest in sites where the most common species did not simultaneously have the greatest functional impacts. Furthermore, redundancy was enhanced in sites where species were less specialised and had more even incidence distributions. Our study demonstrates that the ecological importance of a species depends on its functional traits, but also on the community context. It cannot be assessed without investigating its species-specific performance across multiple functions. Hence, to assess functional redundancy in a habitat and the potential for compensation of species loss, researchers need to study species-specific traits that concern functional performance as well as population dynamics and tolerance to environmental conditions.
- Klíčová slova
- Ecosystem processes, Formicidae, Functional performance, Functional redundancy, Resource consumption,
- MeSH
- biodiverzita * MeSH
- biomasa MeSH
- druhová specificita MeSH
- ekologie MeSH
- ekosystém * MeSH
- Formicidae * MeSH
- populační dynamika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Global change drivers are rapidly altering resource availability and biodiversity. While there is consensus that greater biodiversity increases the functioning of ecosystems, the extent to which biodiversity buffers ecosystem productivity in response to changes in resource availability remains unclear. We use data from 16 grassland experiments across North America and Europe that manipulated plant species richness and one of two essential resources-soil nutrients or water-to assess the direction and strength of the interaction between plant diversity and resource alteration on above-ground productivity and net biodiversity, complementarity, and selection effects. Despite strong increases in productivity with nutrient addition and decreases in productivity with drought, we found that resource alterations did not alter biodiversity-ecosystem functioning relationships. Our results suggest that these relationships are largely determined by increases in complementarity effects along plant species richness gradients. Although nutrient addition reduced complementarity effects at high diversity, this appears to be due to high biomass in monocultures under nutrient enrichment. Our results indicate that diversity and the complementarity of species are important regulators of grassland ecosystem productivity, regardless of changes in other drivers of ecosystem function.
- Klíčová slova
- drought, global change drivers, plant diversity, resource amendment, resource reduction, soil nutrients,
- MeSH
- biodiverzita * MeSH
- eutrofizace * MeSH
- fyziologie rostlin * MeSH
- období sucha * MeSH
- pastviny * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
- Severní Amerika MeSH
Phylogenetic distances of coexisting species differ greatly within plant communities, but their consequences for decomposers and decomposition remain unknown. We hypothesized that large phylogenetic distance of leaf litter mixtures increases differences of their litter traits, which may, in turn, result in increased resource complementarity or decreased resource concentration for decomposers and hence increased or decreased chemical transformation and reduction of litter. We conducted a litter mixture experiment including 12 common temperate tree species (evolutionarily separated by up to 106 Myr), and sampled after seven months, at which average mass loss was more than 50%. We found no effect of increased phylogenetic distance on litter mass loss or on abundance and diversity of invertebrate decomposers. However, phylogenetic distance decreased microbial biomass and increased carbon/nitrogen (C/N) ratios of litter mixtures. Consistently, four litter traits showed (marginally) significant phylogenetic signal and in three of these traits increasing trait difference decreased microbial biomass and increased C/N. We suggest that phylogenetic proximity of litter favours microbial decomposers and chemical transformation of litter owing to a resource concentration effect. This leads to a new hypothesis: closely related plant species occurring in the same niche should promote and profit from increased nutrient availability.
- Klíčová slova
- complementarity versus resource concentration hypotheses, decomposer, litter degradation, niche, phylogenetic biodiversity ecosystem functioning, phylogenetic signal of functional traits,
- MeSH
- bezobratlí fyziologie MeSH
- biodegradace MeSH
- biomasa MeSH
- dusík analýza MeSH
- fylogeneze MeSH
- lesy MeSH
- listy rostlin chemie klasifikace MeSH
- Magnoliopsida klasifikace fyziologie MeSH
- mikrobiota fyziologie MeSH
- půda chemie MeSH
- půdní mikrobiologie * MeSH
- stromy klasifikace fyziologie MeSH
- uhlík analýza MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Francie MeSH
- Názvy látek
- dusík MeSH
- půda MeSH
- uhlík MeSH
Biodiversity-ecosystem functioning experiments (BEF) typically manipulate sown species richness and composition of experimental communities to study ecosystem functioning as a response to changes in diversity. If sown species richness is taken as a measure of diversity and aboveground biomass production as a measure of community functioning, then this relationship is usually found to be positive. The sown species richness can be considered the equivalent of a local species pool in natural communities. However, in addition to species richness, realized diversity is also an important community diversity component. Realized diversity is affected by environmental filtering and biotic interactions operating within a community. As both sown species richness and the realized diversity in BEF studies (as well as local species pool vs observed realized richness in natural communities) can differ markedly, so can their effects on the community functioning. We tested this assumption using two data sets: data from a short-term pot experiment and data from the long-term Jena biodiversity plot experiment. We considered three possible predictors of community functioning (aboveground biomass production): sown species richness, realized diversity (defined as inverse of Simpson dominance index), and survivor species richness. Sown species richness affected biomass production positively in all cases. Realized diversity as well as survivor species richness had positive effects on biomass in approximately half of cases. When realized diversity or survivor species richness was tested together with sown species richness, their partial effects were none or negative. Our results suggest that we can expect positive diversity-productivity relationship when the local species pool size is the decisive factor determining realized observed diversity; in other cases, the shape of the diversity-functioning relationship may be quite opposite.
- MeSH
- biodiverzita * MeSH
- biomasa MeSH
- ekosystém * MeSH
- populační dynamika MeSH
- rostliny * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Arbuscular mycorrhizal (AM) symbiosis is among the factors contributing to plant survival in serpentine soils characterised by unfavourable physicochemical properties. However, AM fungi show a considerable functional diversity, which is further modified by host plant identity and edaphic conditions. To determine the variability among serpentine AM fungal isolates in their effects on plant growth and nutrition, a greenhouse experiment was conducted involving two serpentine and two non-serpentine populations of Knautia arvensis plants grown in their native substrates. The plants were inoculated with one of the four serpentine AM fungal isolates or with a complex AM fungal community native to the respective plant population. At harvest after 6-month cultivation, intraradical fungal development was assessed, AM fungal taxa established from native fungal communities were determined and plant growth and element uptake evaluated. AM symbiosis significantly improved the performance of all the K. arvensis populations. The extent of mycorrhizal growth promotion was mainly governed by nutritional status of the substrate, while the effect of AM fungal identity was negligible. Inoculation with the native AM fungal communities was not more efficient than inoculation with single AM fungal isolates in any plant population. Contrary to the growth effects, a certain variation among AM fungal isolates was revealed in terms of their effects on plant nutrient uptake, especially P, Mg and Ca, with none of the AM fungi being generally superior in this respect. Regardless of AM symbiosis, K. arvensis populations significantly differed in their relative nutrient accumulation ratios, clearly showing the plant's ability to adapt to nutrient deficiency/excess.
- MeSH
- biomasa MeSH
- Dipsacaceae růst a vývoj mikrobiologie fyziologie MeSH
- fylogeneze MeSH
- houby klasifikace izolace a purifikace fyziologie MeSH
- molekulární sekvence - údaje MeSH
- mykorhiza klasifikace izolace a purifikace fyziologie MeSH
- očkovadla agrotechnická klasifikace genetika izolace a purifikace fyziologie MeSH
- půda chemie MeSH
- symbióza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- půda MeSH
