Ecological Research最新文献

Saussurea ochiaiana Kadota (Asteraceae) is a perennial herb endemic to serpentine areas in western Japan. To date, only two locations are known habitats for this species of unknown ecological requirements. Therefore, this study aimed to clarify the environmental factors that limit the germination and seedling growth of this species, which is an essential requirement for designing a suitable conservation strategy. Our germination experiments, in which the achenes were subjected to a gradually increasing temperature and a gradually decreasing temperature after short (1 month) or long (4 months) storage, indicated that the achenes required a long cold stratification for germination. In an experiment where plants collected at the study site were potted individually, they did not grow under strongly shaded conditions consisting of only 10% relative photosynthetic photon flux density (RPPFD), but grew well under moderately shaded conditions (50% RPPFD). No significant differences in seedling growth were observed among the three pH conditions tested (pH 4, 6, and 8). Although average seedling shoot weight was significantly larger at low Ca:Mg molar ratios (0.6 and 0.3) than at high substrate Ca:Mg molar ratios (15 and 1.5) in pot culture experiments, the difference between treatments was not very large (<20%). Habitat conditions suitable for the regeneration of this species are decreasing because of climate change and the depopulation of rural communities (reduction in management); therefore, urgent conservation strategies, including ex situ conservation, are needed.

Natural regeneration after mining activities depends largely on the soil seed bank (SSB) and aboveground vegetation (AGV) richness and composition. We evaluated the species diversity pattern of the SSB and AGV on soil and technosol across second-growth Atlantic Forests (SGFs) after mining tailings deposition in Mariana, southeastern Brazil. Two second-growth Atlantic seasonal semideciduous forests of different stand ages were selected: a 3-year-old stand of SGF re-growing on tailings (SGF tailings) and a 30-year-old stand of native reference forest not affected by tailings (SGF nontailings). Overall, the results showed significant differences in forest attributes (species richness and composition) in the SSB and AGV between the two forest patches evaluated (SGF tailings and SGF nontailings). Moreover, both nonzoochoric and zoochoric dispersed species of AGV showed significant differences between second-growth forests, with higher variability of community-weighted mean in SGF tailings. The result shows smaller differences in species richness between forest types for both SBB (ranging 85 and 90 species) and AGV (~55 species). Despite the time difference between the secondary forest and the absence of zoochoric species in the tailings seed bank, the AGV that are re-growing on mining tailings presented a high proportion of zoochoric species. This pattern of species richness and community composition variability observed in the technosol seed bank, and AGV that are re-growing after the deposition of mining tailings are important recovery indicators for plant communities affected.

Long-term monitoring of forest tree communities is a basis for elucidating forest structure and dynamics and for evaluating ecosystem functions such as primary production. Because global climate change is changing forest ecosystems from the local to the global scale, it is essential to document long-term monitoring data of forests to examine the temporal and geographical trends of forest changes. We report monitoring data of 45 forest plots (average area 0.69 ha; range 0.0325–6.25 ha) at 27 sites in Japan. These plots are situated within 32.38° N to 43.36° N and at elevations ranging from 8 to 2453 m above sea level. The forest plots include both old-growth and secondary forests, and cover various forest biomes, such as warm-temperate evergreen forests, temperate deciduous broadleaved forests, and boreal or sub-alpine coniferous forests. In each plot, all living trees and lianas larger than a certain minimum size (typically 15 cm stem girth at breast height) were repeatedly measured and survival and recruitment of stems were recorded over 5–40 years (average 17.3 years). The data are presented in the format used by the Monitoring Sites 1000 Project in Japan (Ishihara et al. 2011, Ecological Research, 26, 1007–1008) and in the sample-based Darwin Core format. This dataset expands existing open monitoring data for Japanese forests and thereby facilitates further meta-analysis of forest community structures and changes in relation to climate change and other drivers. The complete data set for this abstract is available in electronic format in MetaCat in JaLTER at http://db.cger.nies.go.jp/JaLTER/metacat/metacat/ERDP-2024-03.1/jalter-en.

Ailanthus altissima is one of the major invasive trees at a global scale. Despite numerous reports about its invasiveness in different habitats, so far it was not observed on harsh ultramafic soils and to colonize the vegetation of these outcrops. In this paper we show that the species can also spread in these habitats in the Mediterranean region and is able to cope with the severe anomalies of ultramafic soils. We sampled A. altissima in four ultramafic outcrops of central Italy and in control sites to unravel the behavior of this species toward the typically high soil concentrations of trace metals, such as Ni, Cr and Co, as well the imbalance of the Ca:Mg quotient. A similar sampling was performed for the native Fraxinus ornus that occurs naturally on a broad range of soils, including those from ultramafic rocks. Trace metal concentrations in leaves of both species were below toxicity thresholds, but A. altissima showed lower translocation and bioaccumulation factors (TF and BF, respectively) for Ni. Compared with F. ornus, the invasive species displayed higher leaf concentrations of Mg, thus suggesting a higher tolerance of potentially toxic levels of this element. Moreover, the higher TF and BF values for Ca in both control and serpentine populations suggested that A. altissima was more able to extract and accumulate this macronutrient in leaves in respect to F. ornus. Given the inherent deficiency of this element in ultramafic soils, efficient use of Ca could be a key trait contributing to the invasiveness of A. altissima on these soils.

This dataset summarizes the research on the impacts of Invasive Alien Species (IAS) documented in Brazil from 1981 to 2022 and was used to subsidize the Brazilian Platform on Biodiversity and Ecosystem Services. Impacts of non-native plants and animals, but not microorganisms and fungi, on terrestrial and aquatic (freshwater and marine) environments were included in this review. Most of the literature reviewed consisted of published articles, plus a few book chapters, dissertations, theses, and reports. We found 1003 records of ecological and economic impacts (970 negative and 33 positive) caused by 239 different species, as well as effects on people's well-being. Understanding and assessing all ecological interactions of IAS in nature, as well as evaluating their contributions to humans, can be a complex task. However, the current scientific evidence from Brazil suggests that negative impacts of IAS are far more common than positive impacts, highlighting the importance of avoiding novel introductions. From a conservationist perspective, the simple presence of IAS may cause the negative impact of changing the original structure and processes of nature. This is of special concern in megadiverse countries like Brazil, where interactions among species are multiple and complex. Therefore, we believe this extensive review is an important contribution to the national knowledge of IAS and the improvement of global databases, which must be periodically reviewed. The complete dataset for this abstract published in the Data Article section of the journal is available in electronic format in MetaCat in JaLTER at http://db.cger.nies.go.jp/JaLTER/metacat/metacat/ERDP-2024-01.1/jalter-en.

Plant species with overlapping distributions are expected to experience the same historical events. In contrast, species with different preferred habitat types may exhibit incongruent phylogeographic patterns because of their habitat-dependent demographic changes in spite of their overlapping distributions. On the western side of the Japanese Archipelago, boreal forest and non-forest vegetation were dominant during the last glacial period; subsequently, temperate forests expanded, and open vegetation (e.g., grasslands) decreased. Such vegetation shifts can result in incongruent phylogeographic patterns among temperate forest and grassland species; however, few phylogeographic studies have investigated this hypothesis. Here, we evaluated the phylogeographic structure of two related Geranium species that occur in grassland (Geranium krameri) and temperate forest (Geranium shikokianum) habitats using chloroplast genome sequencing and nuclear genome-wide single-nucleotide polymorphisms genotyping. The phylogeographic structure was stronger for the temperate forest species than the grassland species, despite its currently scattered distribution for grassland species. The observed patterns indicate that the phylogeographic histories of these species were influenced by their habitat configurations since the last glacial period. During the ice age, grasslands in Japan were much more widespread than today; this would have enabled the grassland species to form a continuous distribution, leading to low divergence among regional populations. In contrast, the significant genetic divergence within the forest species can be attributed to the glacial isolation of regional populations. Our genetic results suggest that vegetation transitions have variously controlled the population dynamics of two species with overlapping distributions.

Odontarrhena muralis (Brassicaceae) is a nickel hyperaccumulator species from the Balkans used as a “metal crop” in nickel phytomining. This study aimed to determine the elemental distribution, focusing on nickel, in fresh-hydrated plant tissue (stems, leaves and inflorescences), to clarify where nickel is localized at the tissue and cellular scale-level and to infer the physiological response to its hypertolerance and hyperaccumulation. For the analysis, intact plant organs of O. muralis were subjected to elemental imaging using synchrotron-based micro-X-ray fluorescence (μXRF). The predominant distribution of nickel occurs in the epidermal tissue and at the base of the trichomes, which are also the main sinks for calcium deposition. The obtained results represent a further contribution to the knowledge of the physiological characteristics of this hyperaccumulating “metal crop” species and, consequently, to its application in sustainable metal extraction using phytomining.

The nickel hyperaccumulator Bornmuellera tymphaea has been evaluated for use in agromining in Greece with very promising results. This study examines propagation of this species based on cuttings, which provides rapid multiplication and clonal propagation of genotypes with useful genetic traits and offers obvious advantages over propagation by seed. Apical cuttings, 10 cm long, obtained from plants in the field, were propagated on mist benches under greenhouse conditions. Four treatments based on the rooting medium were evaluated: (a) perlite, (b) perlite + peat 1:1 (v/v), (c) ultramafic soil, and (d) ultramafic soil + perlite 1:1 (v/v). Completely randomized blocks were used in a 4 × 2 factorial design, using 4 different propagation rooting media and 2 levels of auxins (with or without the use of indole-3-butyric acid [IBA]), with 3 replicates of 28 cuttings. The response to perlite medium was best in terms of rooting: 75% without IBA and 71.33% with IBA, and the dry weight of roots was 0.18 g and of shoots 0.34 g. Perlite + peat 1:1 (v/v) medium also resulted in rooting in more than 55% of cuttings whereas cuttings grown in ultramafic soil showed very low rooting (<27%). Based on the findings, B. tymphaea has an aptitude for vegetative propagation by cuttings with survival values and rooting greater than 70%. Perlite combined with the application of auxin (ΙΒΑ) is recommended.