栗山 武夫

Deer species were repeatedly overexploited and protected for their meat and fur and they had strong impacts on ecosystems and human society by damaging crops and planted trees, altering vegetation, deer vehicle collision, and increasing ticks that vector zoonosis. To accomplish appropriate population management, the historical demography and its main driver need to be clarified. In this study, we estimated the historical demography of effective population size ( Ne) of sika deer ( Cervus nippon Temminck) in Hokkaido and Hyogo Prefectures of the Japanese archipelago. We estimated Ne of >100 generations from present (2020) by folded single nucleotide polymorphisms (SNP) frequency spectra and, within 100 generations from present, by linkage disequilibrium between SNP. In Hokkaido, Ne drastically increased around 3.0 ky BP and decreased around 100–150 years ago with the assumption of their generation length as 4 or 9 years. The Ne decreased by a 10th before the recent bottleneck. In Hyogo, Ne increased around 80 and 1 ky BP and decreased around 100–250 years ago. Ne decreased by a 100th before the recent bottleneck. After these recent bottlenecks, Ne of both regions recovered and the current Ne has nearly reaches the highest level of the last 100 ky BP. Literature survey and paleoclimate indicates that the decrease and increase of Ne of sika deer in Japanese archipelago may be caused by variations in the hunting activity of humans rather than climate change or the top predator extinction.

<p>著者らは岐阜県の森林内に設置した自動撮影カメラによって，イノシシSus scrofa幼獣の頸部に噛みつき，捕獲を試みるニホンテンMartes melampusの姿を記録したため報告する．撮影時期は出産ピーク直後の6月下旬であり，襲われたイノシシは生後間もない幼獣であったと考えられる．ニホンテンがイノシシ幼獣を積極的に捕獲し，餌資源として利用しているかは不明であるが，イノシシ幼獣にとって潜在的な捕食者であると考えられる．</p>

© 2018 The Authors. Ecology and Evolution published by John Wiley &amp; Sons Ltd. Dispersal as well as population growth is a key demographic process that determines population dynamics. However, determining the effects of environmental covariates on dispersal from spatial-temporal abundance proxy data is challenging owing to the complexity of model specification for directional dispersal permeability and the extremely high computational loads for numerical integration. In this paper, we present a case study estimating how environmental covariates affect the dispersal of Japanese sika deer by developing a spatially explicit state-space matrix model coupled with an improved numerical integration technique (Markov chain Monte Carlo with particle filters). In particular, we explored the environmental drivers of inhomogeneous range expansion, characteristic of animals with short dispersal. Our model framework successfully reproduced the complex population dynamics of sika deer, including rapid changes in densely populated areas and distribution fronts within a decade. Furthermore, our results revealed that the inhomogeneous range expansion of sika deer seemed to be primarily caused by the dispersal process (i.e., movement barriers in fragmented forests) rather than population growth. Our state-space matrix model enables the inference of population dynamics for a broad range of organisms, even those with low dispersal ability, in heterogeneous landscapes, and could address many pressing issues in conservation biology and ecosystem management.

© 2018, Springer Nature Limited. Ichthyosaurs are extinct marine reptiles that display a notable external similarity to modern toothed whales. Here we show that this resemblance is more than skin deep. We apply a multidisciplinary experimental approach to characterize the cellular and molecular composition of integumental tissues in an exceptionally preserved specimen of the Early Jurassic ichthyosaur Stenopterygius. Our analyses recovered still-flexible remnants of the original scaleless skin, which comprises morphologically distinct epidermal and dermal layers. These are underlain by insulating blubber that would have augmented streamlining, buoyancy and homeothermy. Additionally, we identify endogenous proteinaceous and lipid constituents, together with keratinocytes and branched melanophores that contain eumelanin pigment. Distributional variation of melanophores across the body suggests countershading, possibly enhanced by physiological adjustments of colour to enable photoprotection, concealment and/or thermoregulation. Convergence of ichthyosaurs with extant marine amniotes thus extends to the ultrastructural and molecular levels, reflecting the omnipresent constraints of their shared adaptation to pelagic life.

Water chestnuts (Trapa spp.) dominate many shallow eutrophic lakes, and impact aquatic fauna. Use of Trapa beds by animals may vary with the growth stage of Trapa, but little is known regarding when and how animals use Trapa and nearby, non-Trapa habitat. To clarify seasonal habitat use by the Trapa-feeding chrysomelid beetle (Galerucella nipponensis), we examined seasonal changes in the density of G. nipponensis from Trapa beds and from adjacent emergent vegetation. Furthermore, to determine whether habitat use by beetles is associated with their physiological state, we measured their oviposition and foraging activities. The density of G. nipponensis in each life-stage changed seasonally, with a high density of adults inhabiting emergent vegetation in July, after beetle densities in Trapa beds had declined. Adults collected from Trapa beds showed active egg-laying and foraging activities, while beetles collected from emergent vegetation were in reproductive diapause. This is the first report of G. nipponensis leaving its host plant to initiate summer diapauses in another habitat type.

・兵庫県では野生動物の生息状況と農業被害程度を、地域単位で経年変化を追跡するため、約4200ある農業集落を対象とした鳥獣害アンケートと、約6700人の狩猟者を対象とした出猟カレンダー調査を毎年度実施している。・鳥獣害アンケートは2003年度から開始し、2005年度から2016年度までの12年間の回答率の平均は73%であった。・シカ・イノシシを対象にした出猟カレンダーは1997年度(イノシシについては2002年度)から実施しており、密度の指標として銃猟時の目撃効率、箱わなとくくりわなの捕獲効率を集計している。

・鳥獣害アンケートにおけるシカ・イノシシによる農業被害の程度と、集落周辺の森林面積割合、密度指標の関係性の分析を行った。・シカ・イノシシの密度指標として、出猟カレンダーから集計した銃猟時の目撃効率、箱わなの捕獲効率を用い、農業被害との関係性を比較した。・シカ・イノシシいずれも密度指標と森林面積割合を組み合わせることで、より被害程度が説明され、シカによる被害は、周辺1000m以内での森林面積割合が高い集落で、イノシシによる被害は周辺100mの森林面積割合が高い集落で深刻化しやすい傾向がみられた。・景観構造の違いを考慮した場合、森林内の銃猟時の目撃効率よりも、集落周辺で設置されることの多い箱わなでの捕獲効率の方が、被害程度との関係性が強かった。・目撃効率と被害程度の関係性は、兵庫県全体での個体数管理の目標設定の基準として使われてきたが、集落単位で被害分析や対策の評価を行う場合には、景観構造の違いを考慮し、箱わなでの捕獲効率を指標とすることが有効である。

While induced defense of aquatic organisms against predators has been considerably studied by both laboratory and field research, our understanding is still limited about, for example, whether induced defense is variable between microhabitats within the same lake and how multiple predators influence induced defense in the natural environment. Here, we examined whether a rotifer species, Brachionus calyciflorus showed a different development degree of induced defenses against its predator Asplanchna and cyclopoid copepods between the microhabitats of a macrophyte bed consisting of Trapa species and open water. B. calyciflorus was more abundant and had larger posterolateral spines as a defensive trait in open water than in the Trapa bed. Asplanchna was more abundant in open water than in the Trapa bed, whereas cyclopoids were more abundant in the Trapa bed. Both of the predators significantly affected the development of the defense trait. The effect of Asplanchna on the defense trait was positive, whereas the effect of cyclopoids was negative. Thus, a spatial difference in the development degree of induced defense between the microhabitats occurred as the dense Trapa bed influenced the abundance of the two predators. The results also suggest that the induced defense of B. calyciflorus was effective in reducing the predation pressure from Asplanchna while B. calyciflorus was not able to avoid predation by cyclopoids in the Trapa bed.

The holotype (MHM-K2) of the Eocene cheloniine Tasbacka danica is arguably one of the best preserved juvenile fossil sea turtles on record. Notwithstanding compactional flattening, the specimen is virtually intact, comprising a fully articulated skeleton exposed in dorsal view. MHM-K2 also preserves, with great fidelity, soft tissue traces visible as a sharply delineated carbon film around the bones and marginal scutes along the edge of the carapace. Here we show that the extraordinary preservation of the type of T. danica goes beyond gross morphology to include ultrastructural details and labile molecular components of the once-living animal. Haemoglobin-derived compounds, eumelanic pigments and proteinaceous materials retaining the immunological characteristics of sauropsid-specific beta-keratin and tropomyosin were detected in tissues containing remnant melanosomes and decayed keratin plates. The preserved organics represent condensed remains of the cornified epidermis and, likely also, deeper anatomical features, and provide direct chemical evidence that adaptive melanism a biological means used by extant sea turtle hatchlings to elevate metabolic and growth rates-had evolved 54 million years ago.

Brown and green are the most commonly imitated colors in prey animals because both colors occur in a range of habitats. Many researchers have evaluated survival with respect to background color matching, but the pigment cell mechanisms underlying such coloration are not known. Dorsal coloration of East Asian Takydromus lizards has shifted from green to brown or from brown to green on multiple occasions during the diversification of the genus, thus giving us an opportunity to examine the cellular mechanisms of background color matching. Brown and green skin were found to differ with respect to the morphological characteristics of iridophores, with different thicknesses of the reflecting platelets and the cytoplasmic spacing between platelets, despite a shared vertical arrangement of pigment cells, i.e., xanthophores in the upper layer, iridophores in the middle layer, and melanophores at the bottom of the dermal layer, among the different Takydromus lizards. Iridophores of brown skin reflected longer wavelengths of light than those of green skin, which may be attributed to the thicker platelets and longer distances between platelets in brown skin. We discuss the potential role of genetic and intracellular mechanisms explaining the thickness and orientation of the light-reflecting platelets of iridophores in Takydromus lizards. (C) 2016 Elsevier GmbH. All rights reserved.

The combination of body stripes and vivid blue tail color has independently evolved in different lizard families. To understand how and when lizards developed this coloration, we microscopically compared the embryonic development of pigment cells in two island populations of Plestiodon latiscutatus that exhibit either striped and blue tailed or inconspicuously striped and blue tailed juveniles, based on the newly determined 12 normal developmental stages of embryos from shortly after egg laying to just before hatching. We focus on the role of the melanophores in the body stripe and the role of iridophore morphotypes in the extent of blue tail coloration. The melanophore density in the black background region was higher in lizards with vivid stripes than in lizards with drab stripes. Iridophores started to fill the dermal space that was not yet occupied by melanophores, which resulted in a higher iridophore density in stripes than in the inter-stripe regions. We also discovered that iridophores with thin platelets reflecting blue structural coloration appeared at a specific region in the tail at stage 11. The position of the tail where iridophores emerged coincided with the boundary area separating anterior brown and green colored tail from posterior blue colored tail after hatching.

Juveniles of numerous lizard species have a vividly blue-coloured tail that likely serves to deflect predator attacks toward the autotomizable tail rather than the lizard's body. The shades of blue colour in the tails of juvenile Plestiodon latiscutatus lizards vary across populations, most notably among those island populations with different predator assemblages. Here, we determine if this intraspecific variation is associated with the differences in colour vision capabilities of lizard predator species. If associated, it would be evidence for local adaptation of tail colour phenotype - natural selection is maximizing the conspicuousness of the tail to the dominant predator species to increase the chance of successfully deflecting attacks. We also use transmission electron microscopy (TEM) to determine the proximate cellular mechanisms that produce the shades of blue in different populations. We revealed that lizard tails with vivid blue reflectance evolved in communities with either weasel or snake predators, two groups of animals with the ability to detect blue wavelengths. However, lizard tail UV reflectance was much higher in populations with only snake predators; that snakes can detect UV, yet weasels cannot, suggests that high UV reflectance is an adaptation to increase tail conspicuousness specifically to snake predators. Finally, a cryptic brown tail evolved independently on the islands where birds are the primary lizard predator. We suggest that because birds have keen visual acuity; a brown, camouflaged phenotype is more advantageous. We also determined through TEM that the thickness of light reflecting platelets in iridophores, and densities of iridophores and xanthophores, predicted the wavelengths and intensity of light reflected by the lizard tail. For example, blue coloration was produced by selective reflection of short wavelengths of light by the thin light reflecting platelets of the iridophore. Greater iridophore density increased light reflectance, while greater xanthophore density decreased light reflectance.

Elucidating the ultimate and proximate mechanisms of melanistic color pattern formation has become an important focus of evolutionary biology. There are relatively few studies, however, examining the composition and architecture of pigment cells in melanistic reptiles. The typical color pattern of the skink Plestiodon latiscutatus, which inhabits the Izu Islands and Izu Peninsula of Japan, consists of brown dorsal coloration, five vivid yellowish white stripes, and a blue tail (in juveniles). We have observed melanistic morphs at a low frequency (&lt;0.05%). Based on a histological examination of pigment cells, we determined that the melanistic morph of P. latiscutatus collected from Shikine in the Izu Islands possesses only dermal melanophores and lacks the xanthophores and iridophores seen in the normal coloration. This arrangement of pigment cells differs from the only other studied melanistic lizard, Sceloporus undulatus, in which the dark skin of the melanistic morph results from a simple increase in the density of melanophores relative to xanthophores and iridophores. Our findings indicate that associations between color pattern phenotypes and the expression of candidate color genes, such as Mc1r, are more complex than previously assumed; coloration in reptiles is controlled not only by cellular processes related to single pigment production but also by the differentiation of multiple pigment cells.

Postembryonic changes in the dermal and epidermal pigment cell architecture of the striped and nonstriped morph of the Japanese four-lined snake Elaphe quadrivirgata were examined to reveal stripe pattern formation after hatching. The striped and nonstriped morphs were distinguishable at the hatching, suggesting that the basis of stripe pattern was formed during embryonic development. In the striped morph, the color of stripes changed from red-brown in juveniles to vivid dark-brown in adults, and density of dermal melanophore increased much more in the stripe than background dorsal scales with growth. This increase in density of dermal melanophore was accompanied not only by the increased epidermal melanophore density but also by the change in vertical structures of dermal melanophore. By contrast, the density of epidermal and dermal melanophore evenly increased over the dorsal scales in the nonstriped morph. Thus, the increased vividness of the stripe pattern after hatching is achieved through localized increase of melanophore density particularly in the stripe region but not over the whole dorsal scales. (C) 2015 Wiley Periodicals, Inc.

Using mitochondrial DNA sequences, we surveyed genetic features of 12 individuals of Cynops pyrrhogaster introduced into Hachijojima Island, in order to estimate their possible origin in the main islands of Japan. The phylogenetic analysis revealed that the 12 examined newts of the introduced population display no genetic diversity and share characteristics with the conspecific population of Shikoku and thus belong to the WESTERN Clade proposed by earlier studies. Our results suggest that the Hachijojima population, having experienced a drastic founder effect, stems from very few individuals from the Shikoku District approximately 650 km to the west.

A long-standing interest in ecology and wildlife management is to find drivers of wildlife population dynamics because it is crucial for implementing the effective wildlife management. Recent studies have demonstrated the usefulness of state-space modeling for this purpose, but we often confront the lack of the necessary time-series data. This is particularly common in wildlife management because of limited funds or early stage of data collection. In this study, we proposed a Bayesian model averaging technique in a state-space modeling framework for identifying the drivers of wildlife population dynamics from limited data. To exemplify the utility of Bayesian model averaging for wildlife management, we illustrate here the population dynamics of wild boars Sus scrofa in Chiba prefecture, central Japan. Despite the fact that our data are limited in both temporal and spatial resolution, Bayesian model averaging revealed the potential influence of bamboo forests and abandoned agricultural fields on wild boar population dynamics, and largely enhanced model predictability compared to the full model. Although Bayesian model averaging is not commonly used in ecology and wildlife management, our case study demonstrated that it may help to find influential drivers of wildlife population dynamics and develop a better management plan even from limited time-series data.

It has been observationally confirmed that the color of birds, such as kingfisher and red-flanked bluetail, is a structural color owing to the interference of the light within a sponge structure inside a barb. In this study, we consider the air rod photonic crystal to which disorder is introduced into the translation vectors and the radius as a model of the structural color of red-flanked bluetail; the optical property of the model is numerically analyzed and is compared with that of the structural color. Copyright (C) EPLA, 2014

Predation may create strong natural selection pressure on the phenotype and life history characteristics of prey species. The Izu scincid lizards (Plestiodon latiscutatus) that inhabit the four Japanese Izu Islands with only bird predators are drab brown, mature later, lay small clutches of large eggs, and hatch large neonates. In contrast, skinks on seven islands with both snake and bird predators are conspicuously colored, mature early, lay large clutches of small eggs, and hatch small neonates. We test the hypothesis that these suites of traits have evolved independently on each island via natural selection pressures from one of two predator regimes - birds-only and birds + snakes. Using two mtDNA genes and a nuclear locus, we infer a time-calibrated phylogeny of P. latiscutatus that reveals a basal split between Mikura and all islands south, and Miyake, all islands north, and the Izu Peninsula. Populations inhabiting Miyake, Niijima, Shikine, and Toshima are not monophyletic, suggesting either multiple colonizations or an artifact of incomplete lineage sorting (ILS). We therefore developed novel phylogenetic comparative analyses that assume either a multiple colonization or more restrictive single colonization ILS scenario and found 1) statistically significant support for the of different suites of phenotypic and life history characteristics with the presence of bird-only or bird + snake predator assemblages, and 2) strong phylogenetic support for at least two independent derivations of either the "bird-only" or "snakes + birds" phenotypes regardless of colonization scenario. Finally, our time-calibrated phylogeographic analysis supports the conclusion that the ancestor to modern Izu Island P. latiscutatus dispersed from the mainland to the Izu proto-islands between 3-7.6 million years ago (Ma). These lineages remained present in the area during successive formation of the islands, with one lineage re-colonizing the mainland 0.24-0.7 Ma.

In a color polymorphic snake, Elaphe quadrivirgata, adults exhibit distinct color patterns such as striped, pale-striped, non-striped, banded, and melanistic morphs. To evaluate a heredity model of color pattern polymorphism, we examined correspondence of color morphs between mother snakes and their offspring based on the quantitative evaluation of individual variation in stripe pattern vividness with digital image analysis of skin coloration. Striped, pale-striped, and non-striped morphs were recognized in adult E. quadrivirgata, but the cluster analyses revealed only two groups of hatchlings, which were characterized by the presence and absence of the stripe pattern. Because the stripes of E. quadrivirgata are expected to become vivid with growth but do not fade, hatchlings categorized as the striped morph will become the striped morph in adults, and pale-striped and non-striped morphs will differentiate from the non-striped group of hatchlings after a certain period of growth. Observed frequencies of striped and non-striped neonates hatched from the clutches laid by striped, pale-striped, and non-striped females supported the assumption that the striped/nonstriped pattern polymorphism follows the rule of incomplete-dominance heredity model of one locus with two alleles and that the striped morph is dominant over the non-striped morph. © 2014 by The Herpetological Society of Japan.

To provide histological foundation for studying the genetic mechanisms of color-pattern polymorphisms, we examined light reflectance profiles and cellular architectures of pigment cells that produced striped, nonstriped, and melanistic color patterns in the snake Elaphe quadrivirgata. Both, striped and nonstriped morphs, possessed the same set of epidermal melanophores and three types of dermal pigment cells (yellow xanthophores, iridescent iridophores, and black melanophores), but spatial variations in the densities of epidermal and dermal melanophores produced individual variations in stripe vividness. The densities of epidermal and dermal melanophores were two or three times higher in the dark-brown-stripe region than in the yellow background in the striped morph. However, the densities of epidermal and dermal melanophores between the striped and background regions were similar in the nonstriped morph. The melanistic morph had only epidermal and dermal melanophores and neither xanthophores nor iridophores were detected. Ghost stripes in the shed skin of some melanistic morphs suggested that stripe pattern formation and melanism were controlled independently. We proposed complete- and incomplete-dominance heredity models for the stripe-melanistic variation and striped, pale-striped, and nonstriped polymorphisms, respectively, according to the differences in pigment-cell composition and its spatial architecture. J. Morphol. 274:1353-1364, 2013. (c) 2013 Wiley Periodicals, Inc.

On the island of Hachijojima, central Japan, a formerly abundant population of native lizard, Plestiodon latiscutatus has become endangered by predation from an alien weasel (Mustela itatsi). Recently, an alien lizard, P. japonicus, became established on the island. The impact of the alien lizard and current distribution of the native lizard were assessed by field surveys and DNA analyses. The native lizard was sparsely distributed in the western part of the island. The alien lizard occurred in the northeastern region of the island. Between these regions, several hybrid populations were identified, including some with non-F1 genotypes, suggesting that introgression is occurring. The distribution of the weasel was examined based on field observations, allowing us to estimate predator impacts on both lizard species. We found evidence that the weasel was present throughout the entire island, suggesting that the alien lizard was able to become established despite the presence of the weasel. This indicates that the alien lizard is likely to expand its habitat range and that introgression may spread. We conclude that P. latiscutatus populations will become increasingly endangered by the synergism of genetic introgression from P. japonicus and predation pressure from the weasel.

伊豆諸島はフィリピン海プレート上に形成された南北に連なる海洋島である。本土から数100kmほどしか離れていないため、種の供給地となったであろう日本本土の生物相との比較も行いやすい。本研究で紹介するのは、伊豆諸島と伊豆半島に生息する被食者(オカダトカゲPlestiodon latiscutatus)の形質が地域によって異なること、その淘汰圧として異なる捕食者相(イタチ:哺乳類、シマヘビ:ヘビ類、アカコッコ:鳥類)にさらされていること、さらにその被食者-捕食者系がどのような進化史をたどってきたのかを分子系統地理学により解明する試みの3 点である。今回は特に、捕食者の注意を引き付け、胴体や頭部への攻撃をそらす機能をもつ尾の色に注目する。オカダトカゲは、異なる色覚をもつ捕食者(イタチ、シマヘビ、鳥類)に対応した尾の色を進化させていることが、至近要因(色素細胞の構造)の解明と究極要因(捕食者の色覚との関係、捕食-被食関係の成立)の考察により示唆された。至近要因の解明により、体色は皮膚にある3種類の色素細胞(黄色素胞・虹色素胞・黒色素胞)の組合せで作られ、尾部の茶色・緑色・青色の割合は反射小板の厚さの異なる虹色素胞と黄色素胞の出現位置が体軸にそって前後に移動することで尾の色の地理的な変異を引き起こしていることが示唆された。また究極要因として考えられる捕食者の色覚と尾の色を比較すると、同所的に生息する捕食者の色覚の違いによってヘビ・イタチには目立つ青色を、色覚が最も発達した鳥類には目立たない茶色に適応してきた結果であることが考えられた。また、各島でのオカダトカゲと捕食者の侵入年代のずれによって、トカゲの尾部の色彩は侵入してきた捕食者に応じて複数回にわたり変化した可能性が高いことが予想された。

Aim We infer the biogeography and colonization history of a dispersal-limited terrestrial vertebrate, the Japanese four-lined ratsnake (Elaphe quadrivirgata), to reveal the number of times mainland populations have invaded the Izu Archipelago of Japan, the mainland sources of these colonists, and the time-scale of colonization. We compare these results with those of past studies in an attempt to uncover general biogeographical patterns. Moreover, we briefly examine the significance of colonization history when evaluating the evolution of body size and melanism of the Izu Island E. quadrivirgata populations. Location The Izu Islands (Oshima, Toshima, Niijima, Shikine, Kozu, Tadanae and Mikura), a volcanic archipelago off the Pacific coast of central Japan. Methods We obtained DNA sequences of the mitochondrial cytochrome b gene (1117 base pairs) from 373 individual snakes sampled from seven of the Izu Islands and 25 mainland localities. We employed partitioned Bayesian phylogenetic analyses assuming a relaxed molecular clock to estimate phylogenetic relationships among extant haplotypes and to give an explicit temporal scale to the timing of clade divergence, colonization history and tempo of body-size evolution. Moreover, we employed model-based biogeographical analysis to calculate the minimum number of times E. quadrivirgata colonized the Izu Islands. Results We found evidence that three separate regions of the Izu Archipelago have been colonized independently from mainland ancestors within the past 0.58-0.20 Ma. The Izu Peninsula plus Oshima and Mikura were both colonized independently from lineages inhabiting eastern mainland Japan. The Toshima, Niijima, Shikine, Kozu and Tadanae populations all derive from a single colonization from western mainland Japan. Oshima has been subject to three or possibly four colonizations. Main conclusions These results support the hypothesis that the extreme body-size disparity among island populations of this ratsnake evolved in situ. Moreover, the fact that the dwarf, melanistic population inhabiting Oshima descends from multiple mainland colonization events is evidence of an extremely strong natural selection pressure resulting in the rapid evolution of this unique morphology. These results contrast with theoretical predictions that natural selection pressures should play a decreased role on islands close to the mainland and/or subject to frequent or recent immigration.

Characterizing the spatial variation in the CO2 flux at both large and small scales is essential for precise estimation of an ecosystem&apos;s CO2 sink strength. However, little is known about small-scale CO2 flux variations in an ecosystem. We explored these variations in a Kobresia meadow ecosystem on the Qinghai-Tibetan plateau in relation to spatial variability in species composition and biomass. We established 14 points and measured net ecosystem production (NEP), gross primary production (GPP), and ecosystem respiration (Re) in relation to vegetation biomass, species richness, and environmental variables at each point, using an automated chamber system during the 2005 growing season. Mean light-saturated NEP and GPP were 30.3 and 40.5 mu mol CO2 m(-2) s(-1) [coefficient of variation (CV), 42.7 and 29.4], respectively. Mean Re at 20A degrees C soil temperature, Re-20, was -10.9 mu mol CO2 m(-2) s(-1) (CV, 27.3). Re-20 was positively correlated with vegetation biomass. GPP(max) was positively correlated with species richness, but 2 of the 14 points were outliers. Vegetation biomass was the main determinant of spatial variation of Re, whereas species richness mainly affected that of GPP, probably reflecting the complexity of canopy structure and light partitioning in this small grassland patch.

Microscopically observed of the lizards with conspicuous body stripes and blue tail coloration was to identify types and combination of cells. There was a vertical combination of xanthophores, iridophores and melanophores, with xanthophores in the uppermost layer, iridophores in the intermediate layer, and melanophores in the basal layer, and different vertical combination of pigment cells produced different skin coloration. Skin with yellowish-white had vertical orders of xanthophores, iridophores and melanophores in an identical manner. Skin showing blue color had iridophores above the melanophores. In addition, the thickness of reflecting platelets in the blue tail was less than in the yellowish-white or brown areas in the body. The skin with black coloration had only melanophores.