Abstract X‐ray fluorescence spectroscopy (XRF) is a relatively new method for non‐destructive elemental analysis of herbarium material that meets the scientific interest in being capable of discovering new hyperaccumulator plant species. Since the genus Noccaea (Brassicaceae family) is known to be one of the most numerous in term of the hyperaccumulator plant species it contains, especially those that hyperaccumulate Ni, the herbarium material available worldwide represents a great resource for expanding our knowledge of their elemental profiles. In this first systematic XRF scanning of herbarium specimens of the genus Noccaea, a total of 794 specimens from the collection of the National Museum of Natural History in Paris (MNHN) were analyzed, and the raw values obtained were corrected using regression formulas against inductively coupled plasma atomic emission spectroscopy data. Hyperaccumulation of Ni was detected in 90 specimens covering 21 taxa, with Ni concentrations reaching up to 48,700 mg kg−1 in Noccaea cappadocica, an ultramaficophyte from Syria. Zinc concentrations above the hyperaccumulation threshold were found in 210 specimens covering 23 taxa, most of which belonged to different subspecies of Noccaea caerulescens, with the highest concentration reaching up to 56,200 mg kg−1 in N. caerulescens subsp. caerulescens. Although the accumulation of Ni and Zn is contrasting in most of the specimens studied, in 10 specimens, predominantly belonging to N. caerulescens, simultaneous hyperaccumulation of Ni and Zn was found. This study also revealed previously unknown hyperaccumulation of Ni in several Noccaea taxa, as well as a simultaneous hyperaccumulation of Ni and Zn that needs to be confirmed by further experimental and field studies.

Abstract An instance of extreme accumulation of Zn by a plant species was found in the 19th century, and observations of unusually high concentrations of other elements (Cu, Co, Ni, Cd, Pb, As, Se) were recorded between the 1920s and 1970s. Of relevance to the study of ultramafic areas and their floras is the occurrence of extreme Ni accumulation. The term “hyperaccumulator” was introduced in 1976 to signify a species exhibiting a concentration that can be hundreds or thousands of times greater than that usually found in plants on most common soils. Concentration criteria that allow a species to be regarded as a hyperaccumulator have been defined and refined from time to time. The following account details my own involvement in the discovery of new examples of metal hyperaccumulation, with particular emphasis on Ni accumulation by plants of ultramafic floras worldwide. The interest in hyperaccumulators has prompted investigations into different aspects of the biota of metalliferous soils. The search for new examples of hyperaccumulation continues, aided in part by non‐destructive X‐ray fluorescence scanning of herbarium specimens, which previously served as a resource providing small fragments for sensitive but destructive analysis. Identification of species as hyperaccumulators must be supported by further field exploration to understand the factors governing the level of metal uptake, and to stimulate further work on plant systematics, biochemistry, genetics, and molecular biology. Applications to phytoremediation and agromining are worth pursuing in some cases. Conservation issues are important because many hyperaccumulators are rare and restricted in their distribution.

Abstract Further range expansion of invasive animal species can be prevented by controlling their behavior. Acoustic repellent is a promising approach to deter problematic animals from ecologically sensitive areas. To develop an acoustic repellent system for a green anole that was introduced to the Ogasawara islands in Japan, this study evaluated the deterrent effect of (1) a pattern sound of machine noise and (2) a mixture of artificial and biologically relevant sounds. We created a sound level gradient inside a small experimental cage in a laboratory setting and measured whether green anoles avoided the vicinity of a speaker. In approximately 80% of cases, both the pattern machine sound and the mixture sounds prevented green anoles from stepping into the vicinity of a speaker (<24 cm). The mixture sounds maintained the deterrent effect at a middle distance from a speaker (<72 cm), whereas the pattern machine sound did not work as a strong acoustic repellent at this distance. These results imply that the mixing of biotic and abiotic sounds can improve the effective range of acoustic repellent for green anoles. However, several shortcomings of the acoustic repellent system were also highlighted. Since a green anole is an insectivore predator, our findings will contribute to protecting endangered native insect fauna from the predation of non‐native lizard species.

Abstract The phytoplankton functional group (FG) classification system sensu Reynolds enables evaluating the ecological status of rivers using the Q(r) compositional index. Here, we apply the Q(r) index to analyze the ecological conditions of the Southern Bug River, at the entire river length, in the early 20th century, testing it first on historic river phytoplankton data. Moreover, we combined the FG approach with the saprobic index and taxonomic richness to assess the ecological status of the river more reliably. The Bray–Curtis Similarity index highlighted the spatial clustering of river sites that corresponded well to the bioregions of the Eastern Lowlands and the Pontian Province. The Q(r) index revealed a higher variation in ecological status among sites than the saprobic index. Therefore, we argue that the FG approach provides a sensitive ecological status indication approach for river phytoplankton, including historical human impacts. The method may improve understanding of reference conditions and assessing the ecological status of Ukrainian rivers, as requested by the European Water Framework Directive.

Abstract The aim of this study was to clarify the structure and regeneration status of mixed beech (Fagus crenata) forest on Mt. Toishi in the Sangun mountain range in northern Kyushu, a relatively low‐latitude region in Japan, with emphasis on forests at lower elevations. We focused on a mixed beech forest at a low elevation of Mt. Toishi and compared the forest structure of the target stands, including tree species and size, with the forest structure near the peaks of Mt. Toishi and Mt. Sangun. Deciduous broad‐leaf trees were dominant near the peaks, while evergreen broad‐leaf trees dominated at lower elevations, whereas the relative dominance of beech trees was not significantly different. Near the peaks, the number of large‐diameter beech trees forming the canopy decreased, and small‐diameter trees were present. The proportion of small‐sized trees was lower in the low‐elevation forest area than in the forest area near the peak. Even at lower elevations, juvenile beech trees grew in limited areas on steep slopes along forest roads. These sites suggested that regeneration of beech populations is possible even at low elevation.

Abstract Tropical lowland rainforests are considered to be ecologically important refugia of national and global significance, yet wide‐scale deforestation and degradation of tropical lowland rainforests lead to losses in biodiversity. Seed storage behavior information is required for the effective restoration of these forests. Here, we studied the seed storage behavior of 42 selected tropical lowland rainforest tree species from Sri Lanka with the aim to test the reliability of current experimental methods and predictive models to predict the desiccation sensitivity of seeds. Seed storage behavior was experimentally determined through the 100 seed method and the results were compared with three predictive models; thousand seed weight–moisture content (TSW–MC), seed coat ratio–seed mass (SCR–SM), and phylogenetic affiliation models. Based on the 100 seed method, 28 species were identified as desiccation sensitive and 14 species were identified as desiccation tolerant. Compared to the 100 seed method, the predictability of the SCR–SM model was 70%, whereas the TSW–MC and phylogenetic affiliation models showed 52% and 58% predictability, respectively. Due to its higher predictability, the SCR–SM model has a high potential to be an effective predictive tool of seed storage behavior. This study revealed that tropical lowland rainforests are dominated by trees producing desiccation‐sensitive seeds. Further, species dispersing seeds in the peak rainy season have desiccation‐sensitive seeds, while those dispersing seeds in the normal wet season have desiccation‐tolerant seeds. Another key finding was that 100% of the subcanopy species produce nonorthodox, that is, desiccation‐sensitive seeds, which gradually decrease from subcanopy to understory.

Abstract Disentangling the distribution patterns of biodiversity along altitudinal gradients and their drivers has been a hot topic in ecological research. Different forest strata show multiple distribution patterns influenced by different community assembly mechanisms. Here, we measure the dominant ecological processes affecting three forest strata (tree, shrub, and herb layers) along altitudinal gradients. We sampled plants with different forest strata in 21 plots located from 2500 to 3700 m in Lasha Mountain, northwestern Yunnan. The taxonomic alpha diversity of the herb layer showed a monotonic decreasing trend with increasing altitude, while the shrub layer was characterized by a single peak, and the tree layer showed no significant change with increasing altitude. We observed a decreasing pattern of phylogenetic diversity with increasing altitude in the herb layer, whereas phylogenetic diversity did not change in the tree and shrub layers. The phylogenetic structure of these three layers showed the same pattern: phylogenetic clustering at low altitudes and overdispersion at middle and high altitudes. The diversity and phylogenetic structure of the herb layer were driven by climate (average dry season precipitation) and topographic (slope and aspect) factors, while shrub layer diversity was mainly influenced by tree layer richness. Overall, the phylogenetic structure pattern of the three forest strata changed from clustered to overdispersed with increasing altitude, indicating that environmental filtering was the main driver at low altitudes, while interspecific competition dominated at middle and high altitudes.

The three principal fates of axillary meristem in flowering plants are growth (G), reproduction (R), and inactivity (I), the allocation relationship between each meristem and plant size in annual herbaceous species tends to change with altered precipitation patterns in arid and semiarid grassland. Decreased precipitation and seasonal drought caused the slope of allometry of meristems allocation in the three species significantly different from 1. Plasticity of meristem allocation to G, R, and I in Setaria viridis tended to be significantly greater in August under P(+) and P(++) while in Corispermum macrocarpum tended to be greater in July under P(−), P(− −), D1, and D2.

Abstract Trees in wetlands emit a significant amount of methane (CH4) into the atmosphere which is produced in the soil where anaerobic conditions prevail. However, only very few studies have considered the role of trees in the CH4 budget of mangrove forests. How tree CH4 emissions () vary between and within individuals, and how these emissions vary with the day/night alternation and the tidal cycle, have not yet been elucidated. We measured from buttress roots and stems on individuals of Bruguiera gymnorrhiza of different sizes. We also measured from trees and sediments over a 24‐h cycle. Higher was measured on the buttress roots than on the stems, with a decreasing trend with height along the stems on a majority of trees. exhibited large variations over a 24‐h cycle which were observed for the first time in this study. from sediment was twice higher at low tide compared to just before or after the flood period. from non‐submerged stem positions at high tide was four times higher during the day than during the night. On buttress roots and on stem portion which were submerged, high were measured at the beginning of the ebb tide even at night. A better understanding of variability from mangrove trees and its controls, at different time scales and along spatial gradients is needed for accurate estimation of CH4 budgets of mangrove forests.