Ecological Research

  • STATISTICS

    Vol. 36 (2021)
    No. submitted articles: 267
    No. accepted articles: 92

    stat

    Statistics in the 6 months (2021.07-12)
    Days to First Decision (All Manuscripts): 40.9 (days)
    Days to First Decision (Mss. with Final Decisions Only): 37.8 (days)

    Current issue
    (vol. 37, issue 2)
    Days for acceptance:
    118.71 (58–257)
    Days for Early View:
    158.43 (90–320)
    Days for publication:
    227.86 (167–377)

The 20th ECOLOGICAL RESEARCH AWARD

  • Transitions in coral communities over 17 years in the Sekisei Lagoon and adjacent reef areas in Okinawa, Japan

    Soyoka Muko, Go Suzuki, Mamoru Saito, Takashi Nakamura, Kazuo Nadaoka

    awd_Muko

    Ecological Research vol.34, No. 4 pp. 524–534

    Keywords: Assemblage type; Categorical clustering; Coral cover; Long‐term monitoring; RecruitmentAcoustic monitoring

    Abstract Long‐term monitoring reveals coral community responses to multiple disturbances that allow us to track their trajectories. We assessed the status of coral communities between 2000 and 2017 in the Sekisei Lagoon and adjacent areas in Okinawa, Japan, using an analysis of monitoring data collected from 196 research sites. Using categorical clustering, we ranked the coral cover in the sites according to five groups: (a) high, (b) intermediate, (c) low, (d) rapidly increasing and (e) unrecovered coral cover. We also identified the composition of assemblage types that were categorized according to the dominant species, and calculated the mean number of Acropora spp. juveniles for each group. Severe declines in the coral cover ranking were observed in response to bleaching events in 2007 and 2016. Although the coral cover rank of the other groups slowly returned to previous levels after the 2007 event, group 5, which accounted for 31% of all sites, did not. Group 5 sites were mainly located in the middle and southern area of the Sekisei Lagoon and along the Ishigaki Island, and were dominated by the Acropora spp., that are more susceptible to disturbances. The intermediate number of Acropora juveniles may also have hindered the recovery of corals in group 5 sites. Our study demonstrated that the coral community composition, in particular the proportion of Acropora spp. and juvenile recruitment, influenced the trajectory of coral cover and, therefore, should be considered when predicting the response of coral communities to climate change scenarios.

  • Species‐specific clonality in east Asian island flora: Phylogenetic and environmental constraints

    Junichi Fujinuma, Buntarou Kusumoto, Takayuki Shiono, Yasuhiro Kubota

    awd_Fujinuma

    Ecological Research vol.34, No. 5 pp. 577–586

    Keywords: Biogeography; Community assembly; Ecological niche; Functional trait; Macroecology


    Abstract Plant clonality is a ubiquitous trait observed in many phylogenetic clades and vegetations across tropical to arctic biomes. However, there is no consensus regarding determinant factors of species clonality; especially in the context of species assembly processes, ecological/evolutionary drivers of clonal growth remain largely unknown. To elucidate macroecological drivers of clonality, we examined phylogenetic conservatism/convergence of clonal growth in Japanese vascular plants and explored the ecological role of clonality. We created a dataset of clonal plants that were classified into phalanx, guerrilla and detachable clonal forms for 3,179 species, along with data regarding species geographical distributions and phylogenies. Then, we tested the association of phylogenetic and environmental factors with species clonality for three life‐form groups (fern, herb and woody species), and identified explanatory factors of clonal growth along large‐scale environmental gradients. Species clonality was phylogenetically constrained; specifically, for herb and woody species, phylogenetic signals across all the clonal growth forms, or especially the detachable form in ferns, were significant. Moreover, clonal growth of Japanese vascular plants was largely explained by taxonomic levels, and also partly by temperature, soil fertility, and species diversity in the distribution range, suggesting both processes; taxon‐dependent evolution of vascular plant clonality and evolutionary convergence of clonality across multiple clades of vascular plants relative to environmental constraints. Our findings demonstrated that species‐specific clonal growth, which acts as a trait related to abiotic/biotic niche, contributes to shaping large‐scale plant diversity patterns through species sorting along abiotic gradients.

  • Vegetation changes from 1984 to 2008 on Mount Usu, northern Japan, after the 1977–1978 eruptions

    Shiro Tsuyuzaki

    awd_Tsuyuzaki

    Ecological Research vol.34, No. 6 pp. 813–820

    Keywords: Convergence and divergence; Long‐term monitoring; Permanent plots; Vegetative reproduction; Volcanic succession

    Abstract The revegetation patterns after volcanic eruptions were monitored annually on Mount Usu, northern Japan, using over 25 years to detect successional changes. The vegetation was monitored by 2 × 5 m plots from 1984 and 2008 and by 5 × 5 m plots that were enlarged from the original plots from 1994 to 2008 due to increasing vegetation height. The thick tephra from these eruptions destroyed the former vegetation in 1977 and 1978. Diversity indexes were calculated, and nonmetric multidimensional scaling (NMDS) was conducted using the vegetation data with environmental factors. The cover of dominant species was higher in the large plots probably due to the vegetative expansion. Species richness and diversity continued to increase annually for 30 years after the eruptions. Well‐established plants were perennial forbs and trees and the species replacement occurred consistently. NMDS of small plot data suggested that elevation was related to the first axis, and year, litter volume and distance to the caldera rim were related to the second axis. Plot scores on the first axis suggested that deterministic factors, that is, elevation and its related factors, produced vegetation convergence but those on the second axis suggested that the vegetation change was in response to stochastic factors, such as litter accumulation and its related unmeasured factors, with year. The results indicated that the convergence or divergence was determined by the conflict between the net effects of deterministic and stochastic factors on vegetation development.

  • Responses of daphnids and other zooplankton populations to massive fish kill in Lake Suwa

    Hye‐Ji Oh, Yusuke Oda, Jin‐Yong Ha, Takamaru Nagata, Takayuki Hanazato, Yuichi Miyabara, Masaki Sakamoto, Kwang‐Hyeon Chang

    awd_Oh

    Ecological Research vol.34, No. 6 pp. 856–863

    Keywords: Copepods; Daphnia galeata; Fish predation; Hypomesus nipponensis; Rotifers



    Abstract In 2016, a massive fish kill of the planktivorous pond smelt Hypomesus nipponensis occurred in Lake Suwa, Japan. Pond smelt, which is important fish species from commercial and cultural perspectives, influences the zooplankton community in the lake. Following the massive fish kill, Daphnia galeata appeared and their population density increased to previously unseen levels by summer 2017. To help recover the fish population, larval pond smelt were released into the lake. Consequently, D. galeata has rarely appeared in Lake Suwa since summer 2017, except for a low‐density population observed in May–June 2018. These phenomena indicated that fish predation is a possible primary factor for suppressing daphnid populations in shallow eutrophic lake. Zooplankton populations showed species‐specific responses to the alterations in predation pressure. When the D. galeata population peaked after the fish kill event, rotifers, which are small‐sized competitors of daphnids, and calanoids tended to decrease in density. Rotifers then increased with the decrease in the daphnid populations due to the recovery of fish. Alternatively, cyclopoids, which demonstrated a similar population density following the fish kill event, tended to decrease when the fish population recovered. The population densities of Leptodora cf. kindtii/richardi and Bosmina spp. did not significantly differ between before the massive kill event and after pond smelt recovery. It is believed that the changes in zooplankton population densities observed in the present study may provide insights for further monitoring of aquatic food webs in eutrophic water systems, including Lake Suwa, where re‐oligotrophication is occurring and biological interactions are changing.