Statistical analysis on ecological adaptation of pelagic Amphipoda in the East China Sea

This article studied the diversity of Amphipoda＇s environmental adaptation using statistic method- ology based on the seasonal investigation data obtained from the East China Sea waters （23°30′- 33°N, 118°30′128°E） from 1997 to 2000. Fifty-four Amphipoda species were identified： among which eight species could stand a temperature difference over 10 ℃ and eight species could tolerate the temperature gap ranged from 5 to 10 ℃; while only six species could stand the salinity fluctuation more than 5. Based on above facts as well as calculated optimal temperature and salinity we divided all Amphipoda species into four groups： （1） eurythermic and euryhalinous species including Lestrigonus schizogeneios, L. macrophthalmus, Tetrathyrus forcipatus, L. bengalensis and Hyperi- oides sibaginis; （2） temperate-warm species containing Hyperoche medusarum, Parathemisto gau- dichaudi, Themisto japonica and Hyperia galba; （3） oceanic tropical species consisted of Oxycephalus clausi~ Lyeaea pulex, Eupronoe minuta, Simorhychotus antennarius, O. poreelus, Platyscelus ovoides and Rhabdosoma ahitei; （4） subtropical species involving one nearshore subtropical water species （Corophium uenoi） and 37 offshore subtropical ones. Compared with other zooplankton such as Eu- phausia and Chaetognatha, Amphipoda was characterized by low dominance but wide distribution in the East China Sea, and this could be ascribed to its high adaptation diversity.

Ecological adaptation of Reaumuria soongorica root system architecture to arid environments

The architectural parameters of Reaumuria soongorica root system in different habitats of Gansu Province, China were analyzed to examine its ecological adaptability to arid environments. Results show that： （1） Topological indices of R. Soongorica root sys- tem are small in all habitats, and root branching pattem tends to be dichotomous. Also, the indices gradually increase in the Min- qin windblown sand region and the Zhangye Gobi region in Hexi Corridor, which indicates that drought tends to produce her- ringbone-like root branching pattems. （2） Fractal dimension values ofR. Soongorica root system are small and not obvious in the Minqin windblown sand region and the Zhangye Gobi region in Hexi Corridor, with values of 1.1778 and 1.1169, respectively. Fractal dimension values are relatively large in Jiuzhoutai semi-arid hilly and gully region of the Loess Plateau, which indicates that the R. Soongorica root system has better fractal characteristics in this region than in the other regions. （3） Total branching ra- tios of the R. Soongorica root system in arid regions of Hexi Corridor are smaller than that in the Jiuzhoutai semi-arid hilly and gully region of the Loess Plateau. This shows that root branching ability in the semi-arid region is stronger, and it decreases to some degree with increased drought. （4） The root connection lengths of R. soongorica root system are long in all habitats, but there are significant length differences between the different habitats. The root connection length at the Minqin windblown sand region is the longest. It is concluded that R. soongoriea adapts to arid environments by decreasing root branching, decreasing root overlap and increasing root connection length, which makes its root branching pattern tend to be herringbone-like to reduce com- petition in root internal environment for nutrients and to enhance root absorption rate of nutrients, and ensure effective nutrition space. Thus the roots can absorb enough water and nutrients in resource-poor settings to ensure normal physiological requirements.

Ecological Adaptability of Introduced Bamboo Species

To enrich ornamental bamboo species in south Henan, 22 ornamental bamboo species were introduced from Anji County, Zhejiang Province, and quadrat survey was adopted to study the ecological adaptability of the introduced species. The results showed that 14 of the introduced species survived in south Henan, and particularly Phyllostachys vivax f. aureocaulis, Phyllostachys vivax f. huanwen, Phyllostachys aureosulcata f. spectabilis, Bambusa multiplex, Phyllostachys nigra, Pseudosasa amabilis, Pleioblastus maculatus showed good performance in height growth, diameter growth and resistance, so these species are most suitable for the promotion in south Henan.

Responses of root growth of Alhagi sparsifolia Shap. (Fabaceae) to different simulated groundwater depths in the southern fringe of the Taklimakan Desert, China

Alhagi sparsifolia Shap. （Fabaceae） is a spiny, perennial herb. The species grows in the salinized, arid regions in North China. This study investigated the response characteristics of the root growth and the dis- tribution of one-year-old A. sparsifolia seedlings to different groundwater depths in controlled plots. The eco- logical adaptability of the root systems of A. sparsifolia seedlings was examined using the artificial digging method. Results showed that： （1） A. sparsifolia seedlings adapted to an increase in groundwater depth mainly through increasing the penetration depth and growth rate of vertical roots. The vertical roots grew rapidly when soil moisture content reached 3%-9%, but slowly when soil moisture content was 13%-20%. The vertical roots stopped growing when soil moisture content reached 30% （the critical soil moisture point）. （2） The morphological plasticity of roots is an important strategy used by A. sparsifolia seedlings to obtain water and adapt to dry soil conditions. When the groundwater table was shallow, horizontal roots quickly expanded and tillering increased in order to compete for light resources, whereas when the groundwater table was deeper, vertical roots developed quickly to exploit space in the deeper soil layers. （3） The decrease in groundwater depth was probably respon- sible for the root distribution in the shallow soil layers. Root biomass and surface area both decreased with soil depth. One strategy of A. sparsifolia seedlings in dealing with the increase in groundwater depth is to increase root biomass in the deep soil layers. The relationship between the root growth/distribution of A. sparsifolia and the depth of groundwater table can be used as guidance for harvesting A. sparsifolia biomass and managing water resources for forage grasses. It is also of ecological significance as it reveals how desert plants adapt to arid environments.

Response and adaptation to the accumulation and distribution of photosynthetic product in peanut under salt stress

To clarify the response and adaptability of peanut under salt stress,Huayu 25 was used as the material,and non-salt stress(CK),0.15% salt stress(S1),and 0.3% salt stress(S2) were applied as three treatments.The study analysed the effects of salt stress on photosynthetic characteristics,photosynthetic substances accumulation and distribution as well as the ecological adaptability of peanuts.The results showed that net photosynthetic rate(Pn),SPAD value,leaf area,and peanut yield were reduced under salt stress.Pn in CK was 13.71 and 28.72% higher than that in S1 and S2 at the 50 th day after planting,respectively.At the same growth period,the SPAD value among treatments was ranked as follows: CK>S1>S2.The 100-pod mass,100-kernel mass,kernel rate to pod,and pod mass per plant were reduced under salt stress,and the trend was CK>S1>S2.The distribution proportion of dry matter in different organs of peanut plant was changed to adapt to such stress.Roots under salt stress intensively distributed in a 0-40 cm soil layer for salt resistance.Dry mass proportion in stems and pods increased during the vegetative stage and early period of reproductive stage,respectively.The maximum growth rates of the pod volume,pod dry weight,and seed kernel dry weight all declined,and the pod and kernel volume at harvest were reduced,improving the seed plumpness under salt stress.This finding could be useful in growing peanut in saline soil.

Cyber-Physical-Social System Between a Humanoid Robot and a Virtual Human Through a Shared Platform for Adaptive Agent Ecology

Two artificial agents(a humanoid robot and a virtual human) are enriched with various similar intelligence,autonomy, functionalities and interaction modalities. The agents are integrated in the form of a cyber-physical-social system(CPSS) through a shared communication platform to create a social ecology. In the ecology, the agents collaborate(assist each other) to perform a real-world task(search for a hidden object)for the benefits of humans. A robot-virtual human bilateral trust model is derived and a real-time trust measurement method is developed. The role of taking initiative in the collaboration is switched between the agents following a finite state machine model triggered by bilateral trust, which results in a mixedinitiative collaboration. A scheme is developed to evaluate the performance of the agents in the ecology through the CPSS.The results show that the robot and the virtual human perform satisfactorily in the collaboration through the CPSS. The results thus prove the effectiveness of the real-world ecology between artificial agents of heterogeneous realities through a shared platform based on trust-triggered mixed-initiatives. The results can help develop adaptive social ecology comprising intelligent agents of heterogeneous realities to assist humans in various tasks through collaboration between the agents in the form of a CPSS.

Response of C:N:P in the plant-soil system and stoichiometric homeostasis of Nitraria tangutorum leaves in the oasis-desert ecotone,Northwest China

Nitraria tangutorum nebkhas are widely distributed in the arid and semi-arid desert areas of China.The formation and development of N.tangutorum nebkhas are the result of the interaction between vegetation and the surrounding environment in the process of community succession.Different successional stages of N.tangutorum nebkhas result in differences in the community structure and composition,thereby strongly affecting the distribution of soil nutrients and ecosystem stability.However,the ecological stoichiometry of N.tangutorum nebkhas in different successional stages remains poorly understood.Understanding the stoichiometric homeostasis of N.tangutorum could provide insights into its adaptability to the arid and semi-arid desert environments.Therefore,we analyzed the stoichiometric characteristics of N.tangutorum in four successional stages,i.e.,rudimental,developing,stabilizing,and degrading stages using a homeostasis model in an oasis-desert ecotone of Northwest China.The results showed that soil organic carbon(SOC),total nitrogen(TN),and total phosphorus(TP)contents and their ratios in the 0-100 cm soil depth were significantly lower than the averages at regional and global scales and were weakly influenced by successional stages in the oasis-desert ecotone.TN and TP contents and C:N:P in the soil showed similar trends.Total carbon(TC)and TN contents in leaves were 450.69-481.07 and 19.72-29.35 g/kg,respectively,indicating that leaves of N.tangutorum shrubs had a high storage capacity for C and N.Leaf TC and TN contents and N:P ratio increased from the rudimental stage to the stabilizing stage and then decreased in the degrading stage,while the reverse trend was found for leaf C:N.Leaf TP content decreased from the rudimental stage to the degrading stage and changed significantly in late successional stages.N:P ratio was above the theoretical limit of 14,indicating that the growth of N.tangutorum shrubs was limited by P during successional stages.Leaf N,P,and N:P homeostasis in four successional stages was identified as''strictly homeostasis''.Redundancy analysis(RDA)revealed that soil acidity(pH)and the maximum water holding capacity were the main factors affecting C:N:P stoichiometric characteristics in N.tangutorum leaves.Our study demonstrated that N.tangutorum with a high degree of stoichiometric homeostasis could better cope with the arid desert environment.

Study on Karyotype of Hobby (Falco subbuteo) and Kestrel (Falco tinnunculus)

This paper reported karyotypes of the Hobby and Kestrel collected from the suburb of Qiqihaer City. These karyotypes were compared and analyzed, on the basis of the study of karyotypes of nine birds species in Falconiformes by Bian Xiaozhuang and Li Qingwei. It was considered that differences in habits of birds and ecological environment not only cause falcons to differ from others, but also differences in a genus, even within a species. This difference may result from fusion of microchromosomes.

Phenotypic Plasticity in Embryonic Development of Reptiles:Recent Research and Research Opportunities in China

Adaptive developmental plasticity can enable an organism to modify its phenotype rapidly, in response to local （and perhaps, unpredictable） conditions, by altering reaction norms during development. Previous studies on this topic have been dominated by western scientists, employing western study systems and approaches. Recently, the expansion of Chinese ecological research has seen a broadening of studies taxonomically （phylogenetically）. Here, we briefly summarize research that has been conducted on developmental plasticity in Chinese reptiles over the past two decades, and suggest productive directions for future studies in this field. There are exciting research opportunities in this field in China, and we call for increased collaboration between western and eastern scientists to elucidate the role of developmental plasticity in evolutionary responses of organisms to environmental changes. As human activities increase the intensity and frequency of such changes, the need to understand responses of biological systems becomes an increasingly urgent priority.

Endocast Morphological Variation and Its Driving Forces in Scutiger boulengeri

Cranialendocasts canbeusedasareliable proxy for brain size,reflecting the evolutionary and environmental selection pressure of species.Although studies on endocasts in amphibians have increased in recent years,those performed on endocasts of Anura are comparatively rare,especially at the intraspecific level.Here,using a high-altitude endemic toad-Scutiger boulengeri-as a model,through the application of integrative methods(morphology,anatomy,phylogeny,and ecology),we studied intraspecific variations in endocast morphology and explored its driving forces.Three-dimensional reconstruction and the brain-to-endocranial cavity(BEC)index suggested that the endocast of S.boulengeri can reflect brain morphology to a large extent.Elliptic Fourier analysis andprincipal componentanalysis revealedgreat variability in the cranial endocast morphology among individuals,as well as the variation concentrated in the regions of telencephalon and optic tectum.In the species,individuals with large bodies are accompanied by a larger endocast size;the relative endocast sizes have significant cladedifferences but no sexual dimorphism.Additionally,the relative endocast sizes of S.boulengeri were not associated with phylogenetic history and aquatic preference but were positively correlated with altitude and negatively correlated with oxygen content,temperature,and precipitation factors(annual mean temperature,temperature seasonality,annual precipitation,and precipitation seasonality).Thesefindings suggested that high-altitude and extreme environmental conditions acted as important selectiveforces in morphological variation of the cranial endocastof S.boulengeri.

Sophora davidii： A Native Shrub Used for Rocky Desertification Control and Development

Sophora davidii has strong adaptability and is tolerant of cold,drought,barren soil,fire,trampling,mowing,etc. Besides,it has good ecological benefit and a variety of uses. It is an excellent native shrub species for the control of rocky desertification,as well as the preferred tree species for the ecological control of mountainous areas with severe and extremely severe rocky desertification and shallow soil. It has wide prospects in the follow-up development of the controlled rock desertification regions. The afforestation technology of planting bimonthly seedlings in small ponds has low cost and good effect,so S. davidii is an ideal tree species to replace Dodonaea viscosa in afforestation.

Interspecific differences and ecological correlations between scale number and skin structure in freshwater fishes

Fish skin is mainly composed of the epidermis,dermis,and its derivative scales.There is a wide diversity in scale number in fishes,but the diversity of skin structure lacks systematic histological comparison.This research aimed to improve our understanding of the functional relationship between the scale number and the skin structure in freshwater fishes and to determine which ecological factors affect the scale number and skin structure.First,we presented a method to quantify skin structure in fish and histologically quantified the skin structure of 54 freshwater fishes.Second,we collected the scale number and habitat information of 509 Cyprinidae fishes in China and explored which ecological factors were related to their scale number.Third,common carp and scaleless carp were used as models to study the effects of scale loss on swimming.We found a strong negative correlation between scale thickness and scale number.The main factor affecting the skin structure of fishes was the species’water column position,and the skin of benthic fishes was the most well-developed(thicker skin layers(dermis,epidermis)or more/larger goblet cells and club cells).The scale number was related to two factors,namely,temperature and water column position,and cold,benthic and pelagic adaptation may have contributed to increased scale numbers.Only in benthic fishes,the more well-developed their skin,the more scales.In common carp,scale loss did not affect its swimming performance.In summary,we suggest that there is a rich diversity of skin structure in freshwater fishes,and the scales of fish with well-developed skin tend to degenerate(greater number/smaller size/thinner,or even disappear),but the skin of fish with degenerated scales is not necessarily well developed.

Morphological and skeletal comparison and ecological adaptability of Mandarin fish Siniperca chuatsi and big-eye Mandarin fish Siniperca kneri

Most of the closely related fish species are similar in appearance,with slight differences.This study evaluated 35 morphological characteristic parameters and the number,shape,and spatial location of bones in the skull and vertebrae of the mandarin fish Siniperca chuatsi and big-eye mandarin fish Siniperca kneri.We can understand their ecological adaptability,compare their morphological and skeletal differences,and elucidate the relationship between their phenotypic trait differences and skeletal characteristics.The results were as follows:1.The Student’s t-test results revealed significant differences between S.chuatsi and S.kneri in terms of head depth,head back length,snout length,interorbital distance,distance of the eyes from the oral fissure,and width between the posterior trunk and base of the caudal fin.Principal component and discriminant analysis showed that the main morphological differences between S.chuatsi and S.kneri were in the eye position,head hump and body shape.2.There was no significant difference in the number and shape of the skull and vertebrae between S.chuatsi and S.kneri,but they differed in spatial position.The terminus of the maxilla in S.chuatsi is located at the lower border of the postorbital bone,but at the anterior in S.kneri.The size of head hump is closely related to the spatial location of the splanchnocranium in S.chuatsi and S.kneri.The angles between the caudal vertebrae centrum and each of the following:the neural arch and spine;haemal arch and spine of S.chuatsi are larger than those of S.kneri.In conclusion,the morphological differences between S.chuatsi and S.kneri are closely related to the spatial position of skeleton.These phenotypic differences reflect the ecological adaptation of mandarin fish to different natural environments.

Adaptation to a Warming-Drying Trend Through Cropping System Adjustment over Three Decades:A Case Study in the Northern Agro-Pastural Ecotone of China

Long-term field monitoring data and historical crop data are useful to assess the impacts of climate change and to manage cropping systems. The objectives of this study are to understand the cropping system response to a warming-drying trend in the northern agro-pastural ecotone （NAE） of China and to document how farmers can adapt to the warming-drying trend by changing cropping system structure and adjusting planting date. The results indicate that a significant warming-drying trend existed in the NAE from 1980 to 2009, and this trend significantly decreased crop （spring wheat, naked oat, and potato） yields. Furthermore, the yield decreased by 16.2%-28.4% with a 1℃ increase in maximum temperature and decreased by 6.6%-11.8% with a 10% decrease in precipitation. Considering food security, water use efficiency, and water ecological adaptability in the semi-arid NAE, cropping system structure adjustment （e.g., a shift from wheat to potato as the predominant crop） and planting date adaptation （e.g., a delay in crop planting date） can offset the impact of the warming-drying trend in the NAE. Based on the successful offsetting of the impact of the warming-drying trend in the NAE, we conclude that farmers can reduce the negative effects of climate change and minimize the risk of crop failure by adapting their cropping system structure at the farming level.

Epidermal characters of Tamarix L.(Tamaricaceae) from Northwest China and their taxonomic and palaeogeographic implications

The taxonomical position of species of the genus Tamarix(Tamaricaceae) has been criticized because of their gross morphological similarities(such as slender, smooth and reddish-brown branches,grey-green foliage and scale leaves), and their systematic relationships remain unclear. In this paper, the leaf epidermal features of 17 species from China are studied based on the micro-morphological characters of the epidermal cells, stomata, salt glands, papillae and epidermal hairs. According to the studies, the leaf epidermal features, together with the character of the flower, are taxonomically clearly distinct. The establishment of Tamarix albiflonum is consolidated. Tamarix korolkowi and Tamarix ramosissima have minimal differences in epidermal characters, and the former is suggested to be a junior synonym. Tamarix ramosissima, Tamarix tarimensis, Tamarix arceuthoides and Tamarix hohenackeri are most similar with respect to their leaf epidermis; considering the common morphological features, habit, distribution and especially the hybridization, it is suggested that these four species are closely genetically related and that the variations among them are probably intraspecific. The new taxonomical evidence indicates the occurrence of13 species and four variants in China. Presently, Tamarix is a typical plant of arid and semi-arid regions, but its Eocene ancestors lived in warm and humid climates in the coastal areas of the ancient Mediterranean Sea.Thus, the papillae or epidermal hairs, which are outgrowths of the outer epidermal cells facilitating the leaf to respond to water stress and commonly seen in the plants growing in arid or semi-arid areas rather than the plants in warm and humid climates, are of relatively recent origin in Tamarix. The primitive species lack papillae or epidermal hairs, while in evolved species these structures are abundant. Based on the ecological adaptations of the epidermal features, the palaeogeographic implications of Tamarix in the Late Cenozoic of Northwest China are also discussed.

Coprophilous myxomycetes: Recent advances and future research directions

Species of myxomycetes are adapted to different ecological niches and occupy different microhabitats.The majority of species have a wide ecological amplitude and may be found on various kinds of substrata.Some species have narrower ecological niches and are restricted to or mainly found on one special kind of substratum.Coprophilous species grow on dung or on a substratum in close contact with dung.The vast majority of records stem from moist chamber cultures on dung from herbivorous mammals,but several species have also been recorded on droppings from birds.A limited number of species can be regarded as truly coprophilous in that they have predominantly or in some cases only been recorded on dung.Some of these species are known from very few collections and their dependence on dung may therefore be difficult to judge.No correlation is absolute and species regarded as coprophilous may sometimes,although rarely,turn up on other types of substrata.Dung is rich in bacteria and nutrients and is a favourable substratum for myxomycetes.Many species normally inhabiting other habitats are occasionally found on dung,and up to now about 114 species have been reported from this kind of substratum,a number that will continue to grow.At least three species,Licea alexopouli,Kelleromyxa fimicola and Trichia brunnea,have thick-walled spores,a possible adaptation to passing through the intestinal tract of a herbivore before germination can take place.