Ecological Research

  • STATISTICS

    Vol. 32 (2017)
    No. submitted articles: 536
    No. accepted articles: 126

    stat

    Current issue
    (vol. 33, issue 3)
    Days for acceptance:
    94 (10–147)
    Days for online-first:
    123 (63–178)
    Days for publication:
    262 (95–335)

The 18th ECOLOGICAL RESEARCH AWARD

    
  • Seasonality of leaf litter and leaf area index data for various tree species in a cool-temperate deciduous broad-leaved forest, Japan, 2005–2014

    Shin Nagai, Kenlo Nishida Nasahara, Shinpei Yoshitake, Taku M.Saitoh awd_S_Nagai

    Ecological Research vol.32, No. 3 pp. 297

    Keywords: Deciduous broad-leaved forest; Ground-truth; Leaf litter; Leaf area index (LAI); Leaf mass per area; Leaf seasonality; Japan; Semi-empirical model; Species discrimination; Decadal data set

    Abstract This paper reports seasonal data regarding leaf litter for 14 deciduous broad-leaved species and one evergreen coniferous species as well as leaf area index (LAI) data for the 14 deciduous broad-leaved species in a cool-temperate deciduous broad-leaved forest in Japan. The seasonal leaf biomass of various tree species is important for accurately evaluating ecosystem functions such as photosynthesis and evapotranspiration under climate change. However, there is a lack of freely available, long-term data. We collected litterfall every 1 to 4 weeks from September or October to November or December each year from 2005 to 2014 in Takayama, Japan (36°08′46″N, 137°25′23″E, 1420 m a.s.l.). After sorting the litter into leaves (according to species categories), stems + branches, and “other”, we dried and weighed the litter groups. We also collected seasonal leaf data (number of leaves and leaf length and width) for each broad-leaved species, which we recorded every 1 to 4 weeks from April or May to October or November using multiple target shoots. To estimate the LAI in autumn for each deciduous broad-leaved species, we used a semi-empirical model of the vertical integration of leaf dry mass per unit leaf area. To estimate the LAI in spring and summer, we used the relationship between the LAI in autumn and the seasonal leaf data. Our data provide input, calibration, and validation parameters for determining LAI based on satellite remote-sensing observations or radiative transfer models and for use in ecosystem models.

  • How well are biodiversity drivers reflected in protected areas? A representativeness assessment of the geohistorical gradients that shaped endemic flora in Japan

    Buntarou Kusumoto, Takayuki Shiono, Masashi Konoshima, Atsushi Yoshimoto, Takayuki Tanaka, Yasuhiro Kubota
    awd_Kusumotoawd_Kusumotoawd_Kusumotoawd_Kusumoto

    Ecological Research vol.32, No. 3 pp. 299–311

    Keywords: Continental island; Evolutionary distinctiveness; Minimum set analysis; Plant species richness; Protected area network

    Abstract Protected areas function as a lifeboat that can preserve the origins and maintenance of biodiversity. We assessed the representativeness of biodiversity in existing protected areas in Japan using a distribution dataset and phylogenetic tree for 5565 Japanese vascular plant species. We first examined the overlap of species distribution with the existing protected areas and identified the minimum set representing all plant species. Second, we evaluated the relative importance of environmental variables in explaining the spatial arrangement of protected areas using a random forest model. Finally, we clarified how potential drivers of plant diversity were sufficiently captured within the protected areas network. Although the protected areas captured the majority of species, nearly half of the minimum set areas were selected from outside the existing protected areas. The locations of existing protected areas are mainly associated with geographical and socio-economic factors rather than key biodiversity features (including evolutionary distinctiveness). Moreover, critical biodiversity drivers, which include current climate, paleoclimatic stability, and geographical isolation, were biasedly emulated within the existing protected areas. These findings demonstrate that current conservation planning fails to represent the ecological and evolutionary processes relevant to species sorting, dispersal limitation, and allopatric speciation. In particular, under-representativeness of historically stable habitats that function as evolutionary hotspots or refugia in response to climate changes may pose a threat to the long-term persistence of Japan’s endemic biota. This study provides a fundamental basis for developing prioritization measures to retain species assembly processes and in situ diversification along current climatic and geohistorical gradients.

  • Tree hollows can affect epiphyte species composition

    awd_Tatsumiawd_Tatsumi

    Shinichi Tatsumi, Takayuki Ohgue, Wakana Azuma, Veera Tuovinen, Yume Imada, Akira S. Mori, Göran Thor, Åsa Ranlund

    Ecological Research vol.32, No. 4 pp. 503–509

    Keywords: Biodiversity; Cryptogams; Bryophytes; Lichens; Tree cavities

    Abstract Tree hollows often harbor animals and microorganisms, thereby storing nutritive resources derived from their biological activities. The outflows from tree hollows can create unique microenvironments, which may affect communities of epiphytic organisms on trunk surfaces below the hollows. In this study, we tested whether the species richness and composition of epiphytic bryophytes (liverworts and mosses) and lichens differ above and below tree hollows of Aria japonica and Cercidiphyllum japonicum in a Japanese temperate forest. The species richness of epiphytic bryophytes and lichens did not differ above and below hollows; however, the species composition of bryophytes differed significantly above and below hollows. Indicator species analyses showed that the moss species Anomodon tristis and the liverwort species Porella vernicosa were significantly more common below than above hollows, while the liverwort species Radula japonica and four lichen species, including Leptogium cyanescens, occurred more frequently above than below hollows. Our results highlight that tree hollows can produce unique microenvironments on trunk surfaces that potentially contribute to the maintenance of epiphytic diversity on a local scale.

  • Web image search revealed large-scale variations in breeding season and nuptial coloration in a mutually ornamented fish, Tribolodon hakonensis

    awd_Atsumiawd_Atsumi Keisuke Atsumi, Itsuro Koizumi

    Ecological Research vol.32, No. 4 pp. 567–578

    Keywords: Citizen science; Global climate change; Google Trends; Sexual selection; Reinforcement

    Abstract Geographic variations in reproductive traits are important for evolutionary biology, but often difficult to investigate because of the need for a large-scale survey and the ephemeral nature of secondary sexual characteristics. Here, using web image searches (Google Images and Twitter), we revealed large-scale geographic variations (>1500 km) in breeding timing and nuptial coloration in the mutually ornamented fish, Japanese dace (Tribolodon hakonensis). As this fish is easily caught and many anglers upload their photographs on the web, we were able to find a total of 401 high-resolution photographs from all over Japan. Breeding periods were determined from dates of photographs with/without nuptial coloration, which matched with previous studies. We also found that breeding periods might have advanced three weeks over the last 80 years in the Chitose River, potentially because of climate change. Additionally, the pattern of latitudinal cline for breeding timing revealed delayed timing in higher latitudes, although regional variations were also high. Finally, we quantified the patterns of nuptial coloration for this mutually ornamented fish, and confirmed that over 80% of individuals showed typical colorations, but others showed rare phenotypes that were never previously described, including an intermediate coloration between T. hakonensis and a potentially hybridizing species, T. brandtii. Our web-based method for estimating breeding phenology could be adopted for organisms with temporal sexual characteristics, such as plants (e.g., flowering time) and some fishes. Web image analyses are still preliminarily with many limitations, but could be promising for investigating variations in visible traits.

  • Impact of climate change on alpine vegetation of mountain summits in Norway

    awd_Vanneste Thomas Vanneste, Ottar Michelsen, Bente Jessen Graae, Magni Olsen Kyrkjeeide, Håkon Holien, Kristian Hassel, Sigrid Lindmo, Rozália Erzsebet Kapás, Pieter De Frenne

    Ecological Research vol.32, No. 4 pp. 579–593

    Keywords: Alpine vegetation; Climate change; Resurvey study; Thermophilization; Cryptogams

    Abstract Climate change is affecting the composition and functioning of ecosystems across the globe. Mountain ecosystems are particularly sensitive to climate warming since their biota is generally limited by low temperatures. Cryptogams such as lichens and bryophytes are important for the biodiversity and functioning of these ecosystems, but have not often been incorporated in vegetation resurvey studies. Hence, we lack a good understanding of how vascular plants, lichens and bryophytes respond interactively to climate warming in alpine communities. Here we quantified long-term changes in species richness, cover, composition and thermophilization (i.e. the increasing dominance of warm-adapted species) of vascular plants, lichens and bryophytes on four summits at Dovrefjell, Norway. These summits are situated along an elevational gradient from the low alpine to high alpine zone and were surveyed for all species in 2001, 2008 and 2015. During the 15-year period, a decline in lichen richness and increase in bryophyte richness was detected, whereas no change in vascular plant richness was found. Dwarf-shrub abundance progressively increased at the expense of lichens, and thermophilization was most pronounced for vascular plants, but occurred only on the lowest summits and northern aspects. Lichens showed less thermophilization and, for the bryophytes, no significant thermophilization was found. Although recent climate change may have primarily caused the observed changes in vegetation, combined effects with non-climatic factors (e.g. grazing and trampling) are likely important as well. At a larger scale, alpine vegetation shifts could have a profound impact on biosphere functioning with feedbacks to the global climate.

  • Integrating isotopic, microbial, and modeling approaches to understand methane dynamics in a frequently disturbed deep reservoir in Taiwan

    awd_Itohawd_ItohMasayuki Itoh, Hisaya Kojima, Pei-Chi Ho, Chun-Wei Chang, Tzong-Yueh Chen, Silver Sung-Yun Hsiao, Yuki Kobayashi, Megumu Fujibayashi, Shuh-Ji Kao, Chih-hao Hsieh, Manabu Fukui, Noboru Okuda, Takeshi Miki, Fuh-Kwo Shiah

    Ecological Research vol.32, No. 6 pp. 861–871

    Keywords: Methane production; Methane oxidizing bacteria; Food web model; Isotope ecology; Environmental microbiology

    Abstract It has been estimated that more than 48% of global methane emissions from lakes and reservoirs occur at low latitudes (<24°). To improve this estimate, knowledge regarding underexplored ecosystems, particularly deep lakes and reservoirs in Asian monsoon regions, is needed because the magnitude of methane emissions is influenced by lake bathymetry and climatic conditions. We conducted long-term studies beginning in 2004 at Feitsui Reservoir (FTR) in Taiwan, a subtropical monomictic system with a maximum depth of 120 m to monitor seasonal and interannual variations of three key characteristics and to understand the mechanisms underlying these variations. Key characteristics investigated were as follows: (1) the balance of primary production and heterotrophic respiration as a determinant of vertical oxygen distribution, (2) methane production at the bottom of the reservoir, oxidation in the water column, and emissions from the lake surface, and (3) the contribution of methane-originated carbon to the pelagic food web through methane-oxidizing bacteria (MOB). This review highlights major achievements from FTR studies integrating isotopic, microbial, and modeling approaches. Based on our findings, we proposed two conceptual models: (1) a model of methane dynamics, which addresses the differences in methane emission mechanisms between deep and shallow lakes, and (2) a spatially explicit model linking benthic methane production to the pelagic food web, which addresses the diversity of MOB metabolisms and their dependence on oxygen availability. Finally, we address why long-term studies of subtropical lakes and reservoirs are important for better understanding the effects of climate on low- to mid-latitude ecosystems.