Ecological Research最新文献

The worldwide decline of mangroves, driven by land-use changes, contributes to global carbon emissions. Nevertheless, there is still uncertainty surrounding the effects of mangrove deforestation on carbon emissions. Only a few studies have attempted to quantify its implications for the carbon budget, especially at the landscape level. We conducted a field assessment of carbon stock, losses or emissions associated with the conversion of these ecosystems, along with quantifying the impact of this conversion on the carbon budget using carbon sequestration rates in various types of mangrove ecosystems, including intact and varying ages of naturally regenerated mangroves within the Merlimau–Kuala Sebatu landscape. Results show that the estimated total ecosystem carbon (TEC) stock for clear-cut sites was 149.06 ± 7.56 Mg C ha⁻¹, whereas the TEC stock for intact sites was 280.65 ± 16.92 Mg C ha⁻¹; however, no significant difference was observed (p > 0.05). Using a stock-change approach, the equivalent carbon emissions are 482.93 Mg ha⁻¹ CO₂e. This is among the lowest measured C emissions from land use in the tropics. Remarkably, the landscape-scale carbon budget remained favorable, with a net positive balance of 2835 Mg C yr⁻¹, mainly due to the carbon sink capacity and expansion of natural regeneration of the intact mangrove site (796 Mg C yr⁻¹). Our research identifies a deforestation threshold of 75%, at which the carbon budget approaches neutrality. These findings therefore emphasize the importance of protecting intact forests and managing regenerated mangroves sustainably, as younger mangroves help sequester carbon and reduce deforestation emissions.

Due to policies supporting large-scale expansion of plantation forestry, about 40% of the forests in Japan are planted forests, such as Japanese cedar (Cryptomeria japonica) and hinoki cypress (Chamaecyparis obtusa). We present the largest freely available EcoPlate dataset for planted forests in Japan, comprising data collected from a network of 74 planted forest sites (114 plots) in regions ranging from cool-temperate to subtropical. The EcoPlate is a 96-well microplate that contains three sets of 31 “response wells” with different carbon substrates. The utilization of each carbon substrate by the microbial community is quantified based on the color development of the well during incubation, providing a multifunctional index of the soil microbial community. Soil properties (water content, carbon, nitrogen, the carbon/nitrogen (C/N) ratio, and pH) essential for interpreting the EcoPlate results were also analyzed. Using a standardized protocol, soil was sampled between July and November 2021. A preliminary principal coordinate analysis (PCoA) was performed on the temporal integration of color density using the 31 substrates. PCo1 explained 36.5% of the variance of the overall absorbance of all substrates. A model of environmental factors, including elevation, and a model of soil properties, including pH, water content, and carbon, were the best-fit models. EcoPlate data allow us to test hypotheses related to community ecology and the ecosystem functions of the soil microbial community in planted forests on a regional scale. The complete data set for this abstract published in the Data Article section of the journal is available in electronic format in MetaCat in JaLTER at https://jalter.diasjp.net/data/ERDP-2024-08.

The overabundance of certain deer species is emerging as a critical issue in many forested regions across the Northern Hemisphere, including those in Japan. In the field of deer impact studies, the prevailing notion has been that overabundant deer populations could cause drastic changes of ecosystem states. This study comprises a review of the historical discussion surrounding ecosystem changes caused by deer overabundance, from theoretical frameworks to in situ observations and experiments. The synthesis highlights the potential for state transitions, shifting ecosystems from forest to nonforest states, and in some scenarios to a so-called alternative stable states. However, detecting these transitions poses challenges due to the enduring impacts of past deer activity and the nonequilibrium nature of forest dynamics. Furthermore, this study reveals additional multifield complexities arising from the interactive effects of deer overabundance and global changes on future forest dynamics. To address these challenges, new avenues for research are proposed, emphasizing the importance of sustained efforts in conducting valuable long-term studies.

Crotalaria is a genus of ~600 species of legumes predominantly found in (sub)tropical regions of Africa and Australia. Crotalaria novae-hollandiae from Australia is a polymetallic zinc (Zn)-cadmium(Cd)-copper(Cu) hyperaccumulator, but only when growing in metalliferous soils. This study aimed to test metal tolerance in Australian Crotalaria species to establish whether metal tolerance is a trait shared between Crotalaria species not known to occur on metalliferous soils. The hyperaccumulator Crotalaria novae-hollandiae and two non-metallophytes, Crotalaria mitchellii and Crotalaria medicaginea, were exposed to different treatments containing Cu-lead(Pb)-Zn in the form of spiked soils. Foliar samples were analyzed for total elemental concentrations and spectrophotometric analysis was undertaken to assess photosynthetic pigments (chlorophyll a + b and carotenoids) as indicators of stress and polyphenols as an indicator of tolerance. No significant differences in metal accumulation were found in the Crotalaria species, and all exhibited a high level of tolerance toward Zn. However, C. novae-hollandiae exhibited the greatest tolerance toward Zn but had low tolerance toward Cu, while none accumulated foliar Pb. Tolerance to Zn appears to be a trait shared between the Crotalaria species tested. None of the tested Crotalaria species exhibited tolerance toward Cu, and none accumulated Pb.

We assessed the effects of soil type on the concentrations of seven elements (calcium, potassium, sulfur, phosphorus, iron, manganese, zinc) in plants using x-ray fluorescence (XRF) analysis and plant specimens collected from calcareous and ultramafic soil areas, and ‘general soils’ (other types of soil represented by Brown Forest soils and Andosols) of Japan. Compared with the plants from other types of soils, the means of these seven elements were lower in plants originating from ultramafic soils, especially in phosphorus. Plants from calcareous soil areas had high iron and zinc concentrations on average, but this tendency was biased by plants collected on Mt. Fujiwara, which had extremely high average values of these elements. Calcium concentration in plants had a negative correlation with zinc or iron from calcareous or general soils, respectively, and iron showed positive correlations with zinc, manganese, and sulfur in plants from calcareous, ultramafic, and general soils, respectively. These correlations were not found in plants from general soils, suggesting that these relationships reflect the chemical characteristics of soil types. On the contrary, plants from all soil types showed a positive correlation between sulfur and phosphorus, whereas a positive correlation between potassium and phosphorus was found in plants from calcareous and general soils, but not in ultramafic plants, which instead showed a weak, but statistically significant correlation between potassium and sulfur. Statistically, iron and sulfur concentrations were positively correlated in all soil types, but manganese showed a low correlation with the other elements.

Potentially toxic metals and metalloids (PTMs) may become a concern to plant and animal health when soil concentrations exceed toxicity limits. These limits are often exceeded in polluted environments (anthropogenic sources) and may transfer through the trophic system, from contaminated soil to plants, and thereafter to herbivores and predators. The aim of this mini review was to consider trophic transfer of PTMs in terrestrial ecosystems, focusing on arthropods as the endpoint. ScienceDirect® was used as search engine with a set of keywords. The most assessed PTMs were Cd, Pb, and Zn, and 63% of all PTMs considered in research were attributed to anthropogenic sources. Industrial or mining sites were most frequently studied, and agricultural sites the least. Brassica was the most studied plant genus as the main extractor of PTMs from the soil as they are easy growing food plants known to take up PTMs. Research mostly focused on primary consumers, with Coleoptera being the most investigated arthropod order, probably because of the diversity of the order and its common occurrence worldwide. Most research was conducted in Europe, while South America and Africa only contributed 6.8% and 2.6%, respectively. The majority of the investigated articles (61%) assessed trophic transfer. From those, only 24% directly measured PTM transfer with experimental trials and included only one trophic level, that is, primary consumers, while 7% of research directly measured PTM transfer across multiple trophic levels (primary and secondary consumers).

In subalpine fir wave forests, strips of dead and weakened trees occur perpendicular to the slope next to strips of healthy trees. To reveal the transpiration by weakened Abies veitchii trees exposed to increased atmospheric evaporative demand, we investigated the ecophysiological traits closely related to the growth and transpiration, comparing them with those of the healthy trees and saplings in the fir wave of Mt. Shimagare in central Japan. The transpiration rate (E) was investigated using sap flux sensors to measure heat pulse velocity and compared with the surrogate for the needle water demand, which was computed using a multilayered gas and energy transfer model (modeled E, E_mod). Weakened trees exhibited smaller diameter growth and narrower sapwood than healthy trees, as well as lower heat pulse velocity compared with healthy saplings. However, needle-level traits did not differ significantly between weakened and healthy trees. Needle water potential at midday was as negative as the needle turgor loss point, and the measured heat pulse velocity increased linearly with E_mod but leveled off above a certain E_mod value in weakened trees and healthy saplings, suggesting that trees restricted E to balance the needle water budget. Heat pulse velocity of weakened trees leveled off at E_mod lower than that of healthy saplings, probably due to lower capacity for water supply to the needles. Restriction of E would occur less frequently but be necessary for both weakened and healthy A. veitchii on Mt. Shimagare to avoid hydraulic failure, sacrificing photosynthetic carbon assimilation.

The 10th International Conference on Serpentine Ecology was held in Nancy, France on June 12–16, 2023. The main goals of the conference were to create a platform for the exchange of ideas and experiences and to promote scientific dialogue among scientists from numerous fields who share expertise in the study of ultramafic habitats worldwide. The proceedings of the conference are being published as two Special Issues of Ecological Research, of which this is the second. In this article, we present the major topics and provide some highlights of the contributions to the 10th International Conference on Serpentine Ecology.

Wing morphology plays a pivotal role in avian flight capabilities and ecological adaptations across diverse environments. Consequently, wing measurement data are used frequently in comparative analyses and hypothesis exploration to understand avian evolution. Among the parameters representing wing morphology, wingspan and wing area are relatively challenging to obtain compared to simpler measures such as wing length and hand-wing index. This study aimed to enhance accessibility to existing wingspan and wing area data by compiling measurements from 25 literature sources, in addition to unpublished data. The dataset covers 856 species across 95 families and 28 orders. Although the inclusion proportion varies widely among orders, ranging from 0% to 100%, this initial dataset forms a foundation for a more comprehensive database on avian wing morphology. The complete dataset for this abstract published in the Data Paper section of the journal is available in electronic format in MetaCat in JaLTER at https://jalter.diasjp.net/data/ERDP-2024-04. [Correction added on 6 January 2025, after first online publication: The URL for the dataset has been updated.] The dataset will be updated continuously, with the latest version available on figshare in CSV and Microsoft Excel formats (https://doi.org/10.6084/m9.figshare.23537892.v2).