SPECIAL FEATURE Freshwater biodiversity in human-dominated landscapes
Imperiled freshwater mussels in drainage channels associated with rare agricultural landscape and diverse ?sh communities
J.N.Negishi ?H.Tamaoki ?N.Watanabe ?
S.Nagayama ?M.Kume ?Y.Kayaba ?M.Kawase
Received:11August 2013/Accepted:27March 2014/Published online:23April 2014óThe Japanese Society of Limnology 2014
Abstract Identi?cation of landscape structures that pre-dict the distribution of aquatic organisms has the potential to provide a practical management tool for species con-servation in agricultural drainage channels.We tested the hypothesis that sites with imperiled freshwater mussels have distinct rural landscape structures and are character-ized by the presence of diverse ?sh communities.In central Japan,the proportion of developed land use in surrounding areas was compared among sites with mussel populations (mussel sites)and randomly chosen sites (random sites)across multiple spatial scales (with a radius ranging from 100to 3,000m).Mussel sites were characterized by a much lower proportion of developed land (mean 5–18%)compared with random sites (mean 32–35%)at a scale of B 300m.The areas that met the landscape criteria for mussel sites across multiple scales constituted only 0.23%of the area that was presumed to have suitable slope and elevation as a mussel https://www.doczj.com/doc/3e12789080.html,ndscape metrics derived from mussel sites to locate unknown populations had a low predictability (16.7%).Sites with mussels were located close to each other and had ?sh communities with higher
taxonomic diversity than in sites without mussels.In addition,mussel taxonomic richness was a good predictor of ?sh community diversity.The quantitative measures of landscape structure may serve as a useful tool when pri-oritizing or identifying areas for conservation of mussels and ?sh if spatially autocorrelated distribution of habitat and other critical environmental factors such as habitat connectivity are also considered.
Keywords Development áIndicator áPaddy ?elds áUnionoida áUrbanization
Introduction
In Japan,rice paddy ?elds,which constitute approximately 7%of national land as the most widespread cropland type ([50%;Sato 2001),have been a part of landscapes for centuries,providing habitats for unique sets of species (Natuhara 2012).Of particular importance are the environ-mental characteristics similar to those of natural ?oodplains (Elphick 2000)and the presence of a mosaic of different landscape components (i.e.,paddy ?elds,forests,ponds,and networks of small creeks and ditches)that are closely cou-pled through food webs (Katoh et al.2009).Modernization of landscape elements (i.e.,land consolidation that converts small land parcels into larger ones with the installation of pipeline systems for irrigation water management)and the urbanization of ?elds (i.e.,land use conversion)are both pressing causes of reduced species diversity in rice-paddy landscapes (Takahashi 1994;Natuhara 2012).
There is a growing body of literature on the ecological roles of drainage channel networks in agricultural land-scapes (Herzon and Helenius 2008).The relative impor-tance of ditch communities to regional species diversity has
Handling Editor:Nisikawa Usio.
J.N.Negishi (&)áH.Tamaoki áN.Watanabe
Faculty of Environmental Earth Science,Hokkaido University,N10W5,Sapporo,Hokkaido 060-0810,Japan e-mail:negishi@ees.hokudai.ac.jp
J.N.Negishi áS.Nagayama áM.Kume áY.Kayaba
Aqua Restoration Research Center,Public Works Research Institute,Mubanchi,Kanyuuchi,Kawashimakasada-machi,Kakamigahara,Gifu 501-6021,Japan
M.Kawase
Department of Human Science,Aichi Mizuho College,2-13,Shunko-cho,Mizuho-ku,Nagoya 467-0867,Japan
Limnology (2014)15:237–247DOI 10.1007/s10201-014-0430-7
been relatively well studied,with unique species often being identi?ed(Armitage et al.2003;Williams2004). Degradation of ditch habitat quality has been related to runoff from agricultural crop?elds with high levels of agro-chemicals(pesticides and fertilizers)(Janse et al. 1998;Biggs et al.2007).Physical modi?cations of channel structures including concrete lining and the placement of migration barriers,such as vertical drops,have also been related to decreased species diversity in drainage channel systems(Katano et al.2003;Nagayama et al.2012;Nat-uhara2012).Recent ecological studies with the aim of developing species conservation strategies have empha-sized the importance of landscape structure in accounting for species distribution across multiple spatial scales (Gergel et al.2002;Marchand2004).Such attempts have been made for organisms in riverine channels(e.g.,Wang et al.2001;Cao et al.2013),but not in drainage channel networks.The latter tend to be smaller in size,located in more upstream areas,and regulated more strongly(i.e.,?ow rate;e.g.,Negishi and Kayaba2009),and thus better understanding of ecosystem processes characteristic of drainage channels is needed.
Identi?cation of areas that harbor high species richness at the local scale and/or make major contributions to spe-cies diversity at the regional scale would greatly facilitate prioritization of sites for conservation(Moilanen and Wilson2009).Such a prioritization approach is critically important in paddy-dominated landscapes because drainage channel management for species conservation inevitably assumes secondary importance to that of increased agri-cultural production(Herzon and Helenius2008).Among aquatic organisms,freshwater mussels(order:Unionoida) can be used as an indicator for biodiversity in low-land aquatic ecosystems,especially other macroinvertebrates and?sh(Aldridge et al.2007;Negishi et al.2013). Besides,freshwater mussels are one of the most imperiled groups of organisms(Lydeard et al.2004;Negishi et al. 2008).Several empirical relationships between the com-munity structure and distribution of freshwater mussels and landscape metrics,such as catchment geology,have been reported(Arbuckle and Downing2002;Daniel and Brown 2013).
Landscape structure in the surrounding areas may affect mussel distribution in agricultural drainage channel.First, urbanization could affect mussel habitat quality because ef?uents from industrial and household sources impair water quality(Onikura et al.2006).Local hydraulic con-ditions,which are a strong factor determining mussel dis-tribution(Morales et al.2006;Allen and Vaughn2010), may be altered as a result of?ashier runoff hydrographs from impervious urban surfaces(Xu and Wu2006).Sec-ond,the encroachment of non-agricultural human land uses in surrounding areas often coincide with improvements in agricultural infrastructure in the area,such as the mod-ernization of ditch structures and irrigation systems(J.N. Negishi,personal observation).We hypothesized that sites with remaining populations of freshwater mussels have distinct rural landscape structures.This study aimed to develop a practical scheme for the identi?cation of loca-tions of mussel habitat,where diverse?sh communities also occur based on landscape metrics over a large area ([10,000km2).Speci?c objectives were to(1)identify the landscape structures(i.e.,the areal proportion of non-agricultural areas in surrounding areas)characteristic of mussel habitats at various spatial scales;(2)test the ef?-cacy of the identi?ed landscape structures in predicting potential mussel habitats;and(3)test the use of mussel community structure as an indicator of?sh community structure.We predicted that mussel habitats in drainage channels are associated with rural landscapes having low levels of non-agricultural human land uses and are char-acterized by the presence of?sh communities with rela-tively high species richness.
Methods
Study site
The study was conducted between April and August2011 in the lowlands of the Tokai region,including Aichi,Gifu, and Mie prefectures(Fig.1).We collected as much information about the locations of existing unionoid mussel populations in agricultural channel networks a priori as we could?nd in the published literature,unpublished records, and knowledge from local people and researchers(see Acknowledgements).Between23and26April,each location was visited to con?rm the presence of mussels. Our criteria for study site selection were:(1)sites were located in agricultural channels for single(drainage)or dual(irrigation and drainage)purpose(s);(2)sites had[10 individual live mussels within an approximately2person-hour search;(3)sites were located a minimum of800-m channel length from each other;(4)sites were not con-nected to each other within the same drainage channel networks before connecting to main river channels in downstream areas.The sites located immediately down-stream of agricultural ponds(reservoirs for irrigation water supply)were excluded because there was the possibility that local populations were largely maintained by emi-grants from the source populations within the ponds. Consequently,we identi?ed26sites(hereafter mussel sites;Figs.1,2).These sites had one of the following unionoid taxa:Anodonta spp.,Unio douglasiae nipponen-sis Martens,Inversidens brandti Kobelt,Obovalis omiensis Heimburg,Pronodularia japanensis Lea,or Lanceolaria
grayana Lea.It was later found that one of the mussel sites was located downstream of the other in the same drainage channel and was excluded when conducting?sh and mussel https://www.doczj.com/doc/3e12789080.html,ndscape analyses were redone by excluding this site,but this did not change the interpreta-tion of statistical results and negligibly affected the criteria used to quantify landscape structures.
Delineation of habitable area
We conducted our study in three regions that contained mussel sites,each of which comprised several neighboring watersheds(Fig.1).This approach was employed to reduce the possibility that our analyses contained the area in which distribution of mussels is biogeographically limited by the legacy of marine transgressions.The entire area of the three regions is hereafter referred to as the total area (Fig.2).We recorded the geographical locations of the mussel sites using GPS(CS60,Garmin Co.,USA)and registered on GIS(Arcmap,ver.9.3,ESRI Co.,USA). Using the surface elevation distribution(50-m resolution, Geospatial Information Authority of Japan),a digital ele-vation model(DEM)was generated.A ground surface slope distribution model(50-m resolution;DSM)was also (e)
created based on DEM.We calculated the average eleva-tion and slope of each site by calculating average DEM and DSM values within the100-m radius buffer polygon sur-rounding each site.We carefully examined the data and excluded the slope values where the100-m buffer polygon enclosed unusual topographic variations such as adjacent hill slopes because the DSM was particularly sensitive to such errors(this occurred at?ve sites).Channel slope can limit mussel distribution by potentially mediating hydraulic forces on the benthic habitat conditions(Arbuckle and Downing2002).Temperature can also limit mussel dis-tribution because of the physiological thermal tolerance of mussels and/or that of their host?sh species whose dis-tribution can determine the distribution of mussels(Gal-braith et al.2010;Schwalb et al.2011;Negishi et al.2013; Schwalb et al.2013).Thus,we have delineated the area that fell within the range of slopes(0.001–3.45%)and elevations(13.0–86.71m)as a proxy of temperature vari-ation of the mussel sites as potentially habitable for mus-sels(hereafter habitable area)within the total area(Figs.1, 2).
Landscape structures of mussel sites
To examine how rare the landscape structures of the mussel sites were in the study area,we randomly chose sites (random sites)within the habitable area(total of26sites) (Fig.2).Random sites were used to represent the average landscape structure present within the habitable area,and we did not con?rm the occurrence of mussels in random sites.First,continuous square grid cells of5009500m were generated to cover the habitable area so that all cells were completely contained within them(grid cells).A total of26grid cells(random cells)was selected so that the number of selections in each region equaled the numbers of mussel sites within each region.Central points of each random cell were considered as random sites(Fig.1).The use of5009500-m grid cells was to assure that randomly selected sites were apart from each other and from mussel sites by at least800-m channel length(i.e.,minimum dis-tances among mussel sites).
We de?ned the developed areas whose surface was covered by landscape components that are not agricultural ?elds or natural features such as forests and water bodies (i.e.,rivers and lakes).We used nation-wide land use census data(land use database in1997,Ministry of Land, Infrastructure,Transport and Tourism,50-m grid resolu-tion)and assigned golf courses,residential areas,trans-portation?elds(e.g.,roads and airports),barren land,and commercial districts as the developed landscape compo-nents.We created50-m raster data,with each grid cell being assigned1(developed)or0(other land uses).We calculated the proportion of developed areas for mussels as well as random sites at multiple spatial scales(circles with a buffer radius of100,200,300,500,1,000,or3,000m) using the GIS buffering and zonal and focal statistics functions(Fig.1).
Locating potential sites containing unknown mussel populations
Based on the landscape structures of known mussel sites de?ned by land-use patterns at multiple spatial scales,we attempted to identify the locations of unknown sites with mussel populations(i.e.,potential sites).We delineated and calculated the area that met the landscape structure criteria for the mussel sites at respective spatial scales; the criteria were set at95%con?dence intervals of the means of the proportion of the developed area for mussel sites.We determined the area that met the criteria of each spatial scale,as well as all spatial scales(i.e., potential areas)from the habitable area using the GIS focal statistics function.For example,the potential area constrained by the criteria at all spatial scales refers to the area within which any given locations had the pro-portion of developed land in surrounding areas within the criteria for mussel sites at all spatial scales examined (Fig.2
).
We excluded habitable areas in Mie prefecture(see Fig.1)from further analyses because distant locations rendered frequent visiting for observations and sampling impractical.We initially attempted to randomly choose candidates for potential sites within the potential area as was done for the selection of random sites using the500-m grid cells;the selected cells were referred to as candidate cells.We chose18candidate cells,the number same as that of initially designated mussel sites.However,preliminary analyses revealed that the number of cells meeting such criteria was too small(\10cells)to conduct a random selection(see results for more detail).As an alternative,we selected cells based on the criteria set based on the maxi-mum value of the proportion of developed area at a spatial scale of500m(53.8%),which provided[100cells.When randomly chosen,18candidate cells were placed on areas dominated by large rivers([90%)or the areas without noticeable agricultural drainage channel networks,candi-date cells were re-chosen by a random selection procedure (this occurred once).
Mussel and?sh surveys
Fish and mussel communities were surveyed in the summer period between8and13August when?ow is stable,and no noticeable precipitation was recorded in the preceding 2weeks.In the water management cycles for rice culti-vation in the area,this period typically provides the largest amount of water within the channel(Negishi et al.2013). The exact locations of the potential sites within candidate cells were determined as follows:The geographical coor-dinates for the central points of chosen grid cells were determined by GIS and located in the?eld by GPS.The sampling sites were chosen by the following criteria:Upon arrival at the location,the closest drainage channel was located.The site suitability was con?rmed when it was for drainage or irrigation/drainage purpose(s),had decent water quality and perennial?ow,and was of a comparable size to that of the mussel sites.The presence of perennial ?ow with decent water quality was con?rmed by the occurrence of freshwater Mollusca such as Pleuroceridae sp.and Viviparidae sp.Only those whose wetted channel width was within the range of that in the mussel sites were selected.When the closest one did not meet these criteria, the next closest ones were progressively examined until the criteria were met.
At each study site,two sections having a longitudinal length ten times the average wetted surface width(ran-ge=45–320cm)were set for mussel surveys with a dis-tance of20times the width between each section.In each section,electrical conductivity(EC),pH,and water tem-perature were recorded using a multiparameter water quality probe(WM-22EP;DKK-TOA Co.,Japan).Mussels were quanti?ed by collecting all mussels within the belt transects(a dimension of259the wetted channel width) equally spaced along a longitudinal pro?le.The total number of transects was proportional to the section length (n=4–32),and total areas searched ranged from0.9to 36.8m2.Mussels were collected by thoroughly sieving the sediment using baskets(1-cm mesh),identi?ed,enumer-ated,and measured along their longest shell axes.Fish communities were surveyed by enclosing a section(209 the length of the wetted width)in the area upstream of the mussel survey sections.To avoid disturbing the?sh com-munities,the survey was conducted prior to the mussel survey.Fish were caught by conducting two passes of catches using triangular scoop nets(34cm wide and 33-cm-high mouth opening;44cm long;2-mm mesh) aligned perpendicularly to the channel.Furthermore,spe-ci?c areas such as those with a fast current and along the channel edge were thoroughly searched for?shes using scoop nets(up to5min by two or three personnel depending on the channel size).Fish were identi?ed,enu-merated,and photographed to digitally estimate their body sizes.Collected organisms were released back to the cap-ture area immediately after the measurements had been taken.
Statistical analyses
Repeated measures two-way analysis of variance (ANOVA)was conducted to examine the effects of spatial scale and site characteristics(mussel sites vs.random sites or mussel sites vs.potential sites)and their interactions on the proportion of developed areas in surrounding areas.Site identity was included as a repeated measures factor.When signi?cant interaction terms were detected,the proportion of developed lands was compared between site types at each scale using Student’s t tests.A correlogram of Mor-an’s I was constructed to assess the degree of spatial autocorrelation in the presence/absence data obtained from ?eld surveys on mussels:presence data from the present sites(initially designated mussel sites in addition to some potential sites with mussel populations)and absence data from absent sites(remaining potential sites without mus-sels).Environmental variables(GIS-calculated elevation and slope,water temperature,pH,EC,and?ow rate)were compared between present and absent sites using Welch’s t tests.Fish community metrics were calculated as the abundance,taxonomic richness,and Shannon-Wiener index.These?sh metrics,calculated for both communities, included all taxa and those excluding bitterlings;bitterlings require live mussels for spawning(Negishi et al.2013). Mussel community metrics were calculated with the pooled data from two sections in terms of abundance and mussel taxonomic richness.Fish and mussel abundance was
expressed as density(the number of individuals either per 1m2or100m2).Mussel indicator roles were examined in two ways.First,?sh community metrics were compared between present and absent sites using Welch’s t tests. Second,relationships between mussel and?sh community metrics were examined by regression analysis(12cases in total)with the former as independent and the latter as dependent variables.All statistical analyses were con-ducted in R2.10.1(R Development Core Team2008)with a signi?cance level of0.05.The Bonferroni correction was applied to the statistical signi?cance level when appropriate.
Results
The change pattern of the proportions of developed lands in the surrounding areas in response to variable spatial scales differed between the sites with known mussel populations and those of randomly chosen sites(interaction effect: F5,245=6.8,p\0.001).The differences in landscape structures between two types of sites were particularly high at relatively small spatial scales(Fig.3a).The proportions of developed lands were signi?cantly lower for the sites with known mussel populations compared with those of randomly chosen sites(site effect:F1,49=12.22, p\0.001;Fig.3a).The proportions of developed lands were signi?cantly lower at sites with mussels at the spatial scales of100,200,and300m when compared at respective spatial scales(Fig.3a).
The areal extent of lands(potential areas)that fell within the landscape conditions of mussel sites at different spatial scales became disproportionately less with decreasing spatial scale(Table1).Approximately7%of the total area
was selected as within the slope and elevation range of sites with existing mussel populations(habitable area).The areal extent of the potential area that met the landscape-level criteria of mussel sites across all spatial scales only con-stituted0.23%of the habitable area.The potential sites, which were selected based on the criteria of maximal areal proportion of developed land at a scale of500m(53.8%), had landscape structures similar to those of mussel sites (Fig.3b).The change pattern of the proportions of devel-oped lands in the surrounding areas in response to variable spatial scales did not differ between two types of sites (interaction effect:F5,165=0.17,p=0.97).The potential sites had a proportion of developed lands similar to that of mussel sites in the surrounding area(site effect: F1,33=1.16,p=0.29;Fig.3b)with a signi?cant effect of spatial scale(F5,165=18.84,p\0.001).
In total,2,128individuals were found:1,764P.jap-anensis,118L.grayana,56O.omiensis,78Inversidens brandti,107Anodonta spp.,and5U.douglasiae nip-ponensis.We found mussels in3out of18potential sites (at least one live individual in the quadrat survey) (Fig.4a).A clear spatial structure was revealed in the distribution of present and absent sites with Moran’s correlogram indicating statistically signi?cant positive autocorrelation for small-distance categories(Fig.4b).It is important to note that three potential sites with mussels were close to each other or close to the sites with known mussel populations,augmenting the patchy distribution. Sites with mussels(including the three potential sites with mussels)and those without mussels were similar to each other in the measured environmental variables (Table2).Mean(±SD)mussel density(individuals/m2), irrespective of taxon,at sites with mussel populations was29.6(±57.3)individuals/m2.In total,2,390?sh, consisting of24taxa,were collected(Appendix of Table3);their body length was\15cm.When
compared
between sites with and without mussels,?sh species richness with all taxa included and taxa excluding bit-terling species were both higher at the sites with mussels compared with those without(Fig.5;p\0.001).The Shannon-Wiener index did not differ among site types (p[0.20).Mussel taxonomic richness was positively associated with?sh species richness(both with and without bitterlings)and the Shannon-Wiener index cal-culated from all taxa included(Fig.6).Mussel abundance did not have any predictive effect on?sh community metrics(p[0.12).
Discussion
We demonstrated that the landscape structure surround-ing agricultural drainage channels with imperiled unio-noid mussels was characterized by rural landscapes having a signi?cantly lower level of land development compared with common landscapes in the area with similar elevation and slope ranges.This difference was more pronounced when landscape structure was exam-ined at relatively small spatial scales.These results agree with our prediction that mussel habitats possess rela-tively rare rural landscape features in the region.The interpretation of our?ndings requires caution because
we did not compare landscape structures between the sites with and without mussels.Also,we did not con-strain our analyses to the areas where only the landscape structures varied,with other important factors(see the next paragraph)being more or less controlled when selecting random sites.
The absence of GIS-ready digital data resources of drainage channel networks across a large area prevented us
(a)
(b)
Fig.4Spatial distribution of sites with mussels(?lled circles)and without mussels(open circles)(a)and spatial correlogram of the occurrence(presence or absence)of mussels where the abscissa is distance classes and the ordinate Moran’s I coef?cient(b).In a,three sites accompanied by an arrow denote sites that were initially chosen as potential sites and had mussel populations,whereas the gray areas denote the habitable area.**Signi?cant with Bonferroni-corrected probability(p=0.05/10;p=0.005).*Signi?cant at the probability level p=0.05(i.e.,before applying the Bonferroni correction)
Table2General characteristics of study reaches with(present)and without(absent)freshwater mussels
Present
(n=20a)
Absent
(n=15)
Statistical
signi?cance Elevation(m)43.61±18.1632.88±16.72p=0.08 Slope(%)0.69±0.570.57±0.43p=0.67 Temp.(°C)27.45±2.1026.42±1.35p=0.08 pH7.12±0.697.80±0.62p=0.01 EC(l S/cm)9.81±7.159.41±3.52p=0.83 Flow rate(m3/s)0.19±0.310.15±0.11p=0.63 Mean±SD are shown.Statistical signi?cance as the result of Weltch’s t tests is also shown;signi?cance level is Bonferroni cor-rected(p=0.05/6;p=0.008)
a Sample size was15for slope as the?ve sites were excluded because an unusual land surface slope was estimated because of the presence of a steep hillslope near the channel
Table1Areal extent of the potential area that met the criteria of mussel site landscape structures at different spatial scales and their relative availability(%)relative to total and habitable areas
Area(km2)Availability(%)
Total area6,399.32
Habitable area473.897.41
3,000-m buffer criteria131.2627.70a
1,000-m buffer criteria113.5523.96a
500-m buffer criteria97.6820.61a
300-m buffer criteria64.6313.64a
200-m buffer criteria58.2412.29a
100-m buffer criteria45.689.64a Multiple-scale criteria 1.070.23a
For example,7.41%of total area is considered suitable for mussel habitat based on the range of elevation and slope of sites with mus-sels;9.64%of the habitable area was considered suitable for mussel habitat when considering landscape structure obtained for the sur-rounding area of mussel sites at the scale of100m(the area within a circular buffer having a radius of100m)
a These values were calculated as a proportion relative to the habit-able area
from taking into the account spatial attributes of drainage channel networks when delineating areas potentially suit-able as mussel habitats.For example,drainage density(i.e., total length of channels in a given unit area;see Benda
et al.2004),which is analogous to habitat availability, could have been particularly meaningful.Thus,it is pos-sible that some of the random sites were selected from areas where highly urban landscapes dominated and as a result few drainage channels existed(relatively low habitat availability).Consequently,the differences in landscape structure between the mussel and random sites can be partly a re?ection of the differences in land-use patterns (rural vs.urban)and not necessarily those around drainage channels.Despite such limitations,the results implied that a quantitative measure of rare landscape structure is useful when narrowing down the areas where mussel habitat is likely to occur.
We showed that areas with landscape structures charac-teristic of mussel sites across multiple spatial scales consti-tuted only a fraction of the habitable area in the region (0.23%)and was much less when compared with the areas estimated at respective spatial scales(Table2).This suggests that mussel sites can be more accurately de?ned by consid-ering landscape metrics quanti?ed at multiple spatial scales. Our?ndings underscore the importance of considering land-scape structures at multiple spatial scales when explaining organism distribution patterns(see also Marchand2004; Stephens et al.2004).Furthermore,landscape structure characteristic of mussel sites were more pronounced and became rarer at relatively small spatial scales.Cao et al. (2013)examined the relationships between landscape metrics and riverine mussel habitat conditions and also reported the disproportionately strong in?uences of landscape conditions in a close proximity(i.e.,riparian zone).In the study region, the increase of developed land surfaces within the area a rel-atively short distance from mussel sites likely causes a dis-proportionately large drop in potential habitat availability and may degrade mussel habitat quality more
severely.
Unknown mussel populations were found at only a few potential sites(16.7%),indicating limited usefulness of landscape structure as a single predictor of mussel habitat distribution.A patchy distribution of sites with mussels was apparent,and an understanding and incorporation of its cause can improve the predictive model of mussel distribution. Patchy distribution of mussels(mussel beds)is relatively well reported at within-channel scales as well as at broader regional to continental scales(Vaughn and Taylor2000; Strayer2008).At larger scales,in particular,host?sh spe-cies’distribution may be the one of the most important fac-tors(Vaughn and Taylor2000;Schwalb et al.2011).A patchy distribution can be caused by natural barriers(e.g., drainage divide)for the dispersal of mussels(or host?sh species)or as a result of human-induced fragmentation and shrinkages of formerly broad distribution range(Strayer 2008).Fish migrate seasonally up from rivers to drainage channels or rice paddies via drainage channels(e.g.,Katano et al.2003).The placements of vertical drops impassable for ?sh is common in modernized drainage channel networks (Miyamoto2007).In agricultural channels,therefore,the reduction or loss of connectivity among channels and/or between channels and downstream rivers might have frag-mented the mussel habitat by limiting movement of host?sh with attached glochidia.Other potentially important factors on a local scale,such as?ow velocity,hydraulic forces,and physical channel structures,may also play a role in con-trolling the distribution of mussels(Allen and Vaughn2010; Matsuzaki et al.2011;Nagayama et al.2012;Negishi et al. 2013).These factors independently or in combination with other factors can affect habitat conditions of mussels directly or indirectly by limiting distribution of host?sh species. Future studies should examine the relative importance of multiple factors such as habitat fragmentation and local habitat conditions in relation to natural dispersal ranges of host?sh species(Schwalb et al.2011;Cao et al.2013; Schwalb et al.2013).
Fish species richness was higher at sites with mussels compared to sites without mussels despite similar physico-chemical habitat conditions.This is consistent with the ?ndings that the occurrence of mussels is associated with the presence of relatively species-rich?sh communities (e.g.,Vaughn and Taylor2000;Negishi et al.2013).Mussel species such as I.brandti,O.omiensis,and P.japanensis co-occur with bitterlings through host-parasite relationships (Kitamura2007;Terui et al.2011).Importantly,when the bitterlings were removed,signi?cant differences in?sh community species richness remained.This implies that the greater?sh species richness observed in the mussel sites was not the sole consequence of the addition of species having a commensal relationship with mussels,but also several other ecological processes(Negishi et al.2013). Furthermore,the mussel taxonomic diversity gradient pre-dicted?sh community taxonomic richness with mussels and the Shannon-Wiener index relatively well.We previously tested?sh and mussel communities in a\100m2area including some of the mussel sites used in the present study and reported the relationships between?sh and mussel community structure in different seasons(Negishi et al. 2013).A discrepancy in the present study is that Negishi et al.(2013)reported less explanatory power of mussels for ?sh community structure in the summer period.A cause of such a discrepancy may be scale-dependent relationships between the community structure of?sh and mussels(e.g., Schwalb et al.2013).The mechanisms between species richness and?sh community structure also merit future research.We argue that unionid mussel can be used as an indicator of?sh habitat quality over a large scale ([10,000km2)at least within the area having elevation and slope ranges of mussel sites.
Our overall?ndings suggest that the quantitative measures of landscape structure may serve as a useful tool when prioritizing or identifying areas for conserva-tion of mussels and?sh if spatially autocorrelated dis-tribution of habitat and other critical environmental factors such as local habitat quality and habitat connec-tivity are also considered.It is important to recognize the landscape structure in the rural landscape has changed in recent decades largely because of abandonment of agri-cultural lands and land development associated with urbanization(Nakamura and Short2001;Fujihara et al. 2005).Therefore,the landscape criteria quanti?ed in the present study should not be taken as an ideal habitat condition for https://www.doczj.com/doc/3e12789080.html,rmation on the historical dis-tribution of mussels and land-use changes across a large area would provide crucial insights into optimal habitat conditions for mussels.
Acknowledgments Members of Gifu–Mino Ecological Research Group,in particular Y.Miwa and K.Tsukahara,provided logistical support in the?eld.J.Kitamura of Mie Prefectural Museum provided us with information on mussel habitats.We are also indebted to two anonymous reviewers whose comments greatly improved the article. We thank the Global COE program of MEXT at Hokkaido University and the Ministry of Environment,Japan,for funding the research. This work was also supported by a Grant-in-Aid for Young Scientists (B)to JNN(24710269).
Appendix See Table3.
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Table3Taxon list and general characteristics of?sh communities in the study reaches
Family Species name Present(n=20)Absent(n=15)
Cyprinidae
Rhodeus ocellatus ocellatus17.12±45.86(194.44)0
Tanakia lanceolata35.81±94.88(395.83)0
Tanakia limbata190.86±404.25(1,693.12)0
Carassius sp. 6.43±18.00(74.07) 2.22±8.31(33.33)
Nipponocypris sieboldii85.78±173.04(732.64)40.30±150.77(604.44)
Nipponocypris temminckii46.37±101.26(324.79) 2.47±9.24(37.04)
Zacco platypus 6.82±23.67(105.82)10.15±21.54(71.11)
Abbottina rivularis9.29±39.31(180.56)0
Gnathopogon elongatus65.12±208.52(958.33) 3.54±9.16(30.86)
Hemibarbus barbus0 1.19±4.43(17.78)
Pseudogobio esocinus 4.83±11.91(48.61)0
Sarcocheilichthys variegatus variegatus0.17±0.76(3.47)0
Rhynchocypris logowskii steindachneri 1.10±4.07(18.52)7.11±21.78(86.42)
Rhynchocypris oxycephalus jouyi0.17±0.76(3.47)0
Pseudorasbora parva 4.08±16.63(76.39)0
Adrianichthyidae
Oryzias latipes59.48±183.58(833.33)225.91±613.96(2,455.56) Cobitidae
Cobitis biwae 1.66±4.48(15.87)29.71±107.92(433.33)
Cobitis sp. 1.19±5.19(23.81)0
Misgurnus anguillicaudatus63.48±103.56(370.37)109.06±199.33(740.74)
Paramisgurnus dabryanus0 3.29±12.32(49.38) Gobiidae
Rhinogobius sp.42.67±36.65(128.47)75.64±134.90(444.44) Odontobutidae
Odontobutis obscura0.69±3.03(13.89)0
Petromyzontidae
Lethenteron reissneri00.82±3.08(12.35) Siluridae
Silurus asotus00.46±1.73(6.94) Abundances for the sites with and without mussels are shown;mean±SD(maximum values;minimum values were all zero)
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The way 的用法 Ⅰ常见用法： 1)the way+ that 2)the way + in which（最为正式的用法） 3)the way + 省略（最为自然的用法） 举例：I like the way in which he talks. I like the way that he talks. I like the way he talks. Ⅱ习惯用法： 在当代美国英语中，the way用作为副词的对格，“the way+ 从句”实际上相当于一个状语从句来修饰整个句子。 1)The way =as I am talking to you just the way I’d talk to my own child. He did not do it the way his friends did. Most fruits are naturally sweet and we can eat them just the way they are—all we have to do is to clean and peel them. 2）The way= according to the way/ judging from the way The way you answer the question, you are an excellent student. The way most people look at you, you’d think trash man is a monster. 3）The way =how/ how much No one can imagine the way he missed her. 4）The way =because
The way的用法及其含义（二） 二、the way在句中的语法作用 the way在句中可以作主语、宾语或表语： 1.作主语 The way you are doing it is completely crazy.你这个干法简直发疯。 The way she puts on that accent really irritates me. 她故意操那种口音的样子实在令我恼火。The way she behaved towards him was utterly ruthless. 她对待他真是无情至极。 Words are important, but the way a person stands, folds his or her arms or moves his or her hands can also give us information about his or her feelings. 言语固然重要,但人的站姿,抱臂的方式和手势也回告诉我们他(她)的情感。 2.作宾语 I hate the way she stared at me.我讨厌她盯我看的样子。 We like the way that her hair hangs down.我们喜欢她的头发笔直地垂下来。 You could tell she was foreign by the way she was dressed. 从她的穿著就可以看出她是外国人。 She could not hide her amusement at the way he was dancing. 她见他跳舞的姿势，忍俊不禁。 3.作表语 This is the way the accident happened.这就是事故如何发生的。 Believe it or not, that's the way it is. 信不信由你, 反正事情就是这样。 That's the way I look at it, too. 我也是这么想。 That was the way minority nationalities were treated in old China. 那就是少数民族在旧中
定冠词the的用法： 定冠词the与指示代词this ,that同源,有“那(这)个”的意思,但较弱,可以和一个名词连用,来表示某个或某些特定的人或东西. (1)特指双方都明白的人或物 Take the medicine.把药吃了. (2)上文提到过的人或事 He bought a house.他买了幢房子. I've been to the house.我去过那幢房子. (3)指世界上独一无二的事物 the sun ,the sky ,the moon, the earth (4)单数名词连用表示一类事物 the dollar 美元 the fox 狐狸 或与形容词或分词连用,表示一类人 the rich 富人 the living 生者 (5)用在序数词和形容词最高级,及形容词等前面 Where do you live?你住在哪? I live on the second floor.我住在二楼. That's the very thing I've been looking for.那正是我要找的东西. (6)与复数名词连用,指整个群体 They are the teachers of this school.(指全体教师) They are teachers of this school.(指部分教师) (7)表示所有,相当于物主代词,用在表示身体部位的名词前 She caught me by the arm.她抓住了我的手臂. (8)用在某些有普通名词构成的国家名称,机关团体,阶级等专有名词前 the People's Republic of China 中华人民共和国 the United States 美国 (9)用在表示乐器的名词前 She plays the piano.她会弹钢琴. (10)用在姓氏的复数名词之前,表示一家人 the Greens 格林一家人(或格林夫妇) (11)用在惯用语中 in the day, in the morning... the day before yesterday, the next morning... in the sky... in the dark... in the end... on the whole, by the way...
“tｈｅwａｙ+从句”结构的意义及用法 首先让我们来看下面这个句子: Ｒead the foｌloｗｉnｇpassagｅａnd talkａbout ｉt wi ｔh your classmaｔes．Try tｏｔeｌl whaｔyｏu thiｎk ｏf Tom aｎd ｏｆｔhe ｗay the chiｌｄrenｔrｅated ｈim. 在这个句子中，ｔhe waｙ是先行词,后面是省略了关系副词that或in whｉch的定语从句。 下面我们将叙述“the ｗaｙ+从句”结构的用法。 1.tｈe wａy之后，引导定语从句的关系词是tｈat而不是hoｗ,因此，<<现代英语惯用法词典＞＞中所给出的下面两个句子是错误的：Ｔhｉs is ｔｈeｗayｈowｉtｈａppened. This is the way how he ａlwａｙs treats me. 2．在正式语体中,thaｔ可被in which所代替;在非正式语体中，ｔhat则往往省略。由此我们得到theｗay后接定语从句时的三种模式：1) tｈe ｗaｙ＋ｔhａt-从句２）the way +ｉn whiｃh－从句3) the ｗay +从句 例如：Ｔｈe way(in whiｃh ，thａt) ｔhｅｓｅｃomｒade ｓloｏｋａｔｐrobｌems is wrong．这些同志看问题的方法
不对。 Ｔｈｅｗａy(that ,ｉn ｗhiｃh)yoｕ’ｒe doinｇit is comple ｔeｌy crａzy.你这么个干法,简直发疯。 Wｅａdmiｒｅd him for thｅｗay ｉｎｗhｉch he fａｃeｓdiｆficultieｓ． Waｌlａｃe ａｎd Ｄarwiｎｇreed ｏn the way ｉｎwhi ｃh ｄｉfｆｅrｅnt forms ｏf life had ｂegｕn.华莱士和达尔文对不同类型的生物是如何起源的持相同的观点。 Thｉs is ｔｈe ｗaｙ（tｈａｔ) hｅdｉd it. I lｉkeｄｔhe waｙ(ｔhat) ｓｈeｏｒganized ｔhe ｍeetｉng． 3.theｗay(tｈat)有时可以与hｏw(作“如何”解）通用。例如： That’s tｈe ｗaｙ(tｈaｔ) shｅspoke. = Tｈat’s how shｅspoke.
表示“方式”、“方法”，注意以下用法： 1.表示用某种方法或按某种方式，通常用介词in(此介词有时可省略)。如： Do it (in) your own way. 按你自己的方法做吧。 Please do not talk (in) that way. 请不要那样说。 2.表示做某事的方式或方法，其后可接不定式或of doing sth。 如： It’s the best way of studying [to study] English. 这是学习英语的最好方法。 There are different ways to do [of doing] it. 做这事有不同的办法。 3.其后通常可直接跟一个定语从句(不用任何引导词)，也可跟由that 或in which 引导的定语从句，但是其后的从句不能由how 来引导。如： 我不喜欢他说话的态度。 正：I don’t like the way he spoke. 正：I don’t like the way that he spoke. 正：I don’t like the way in which he spoke. 误：I don’t like the way how he spoke. 4.注意以下各句the way 的用法： That’s the way (=how) he spoke. 那就是他说话的方式。 Nobody else loves you the way(=as) I do. 没有人像我这样爱你。 The way (=According as) you are studying now, you won’tmake much progress. 根据你现在学习情况来看，你不会有多大的进步。 2007年陕西省高考英语中有这样一道单项填空题： ——I think he is taking an active part insocial work. ——I agree with you_____. A、in a way B、on the way C、by the way D、in the way 此题答案选A。要想弄清为什么选A，而不选其他几项，则要弄清选项中含way的四个短语的不同意义和用法，下面我们就对此作一归纳和小结。 一、in a way的用法 表示：在一定程度上，从某方面说。如： In a way he was right.在某种程度上他是对的。注：in a way也可说成in one way。 二、on the way的用法 1、表示：即将来(去)，就要来(去)。如： Spring is on the way.春天快到了。 I'd better be on my way soon.我最好还是快点儿走。 Radio forecasts said a sixth-grade wind was on the way.无线电预报说将有六级大风。 2、表示：在路上，在行进中。如： He stopped for breakfast on the way.他中途停下吃早点。 We had some good laughs on the way.我们在路上好好笑了一阵子。 3、表示：(婴儿)尚未出生。如： She has two children with another one on the way.她有两个孩子，现在还怀着一个。 She's got five children，and another one is on the way.她已经有5个孩子了，另一个又快生了。 三、by the way的用法
The way的用法及其含义（一） 有这样一个句子：In 1770 the room was completed the way she wanted. 1770年，这间琥珀屋按照她的要求完成了。 the way在句中的语法作用是什么？其意义如何？在阅读时，学生经常会碰到一些含有the way 的句子，如：No one knows the way he invented the machine. He did not do the experiment the way his teacher told him.等等。他们对the way 的用法和含义比较模糊。在这几个句子中，the way之后的部分都是定语从句。第一句的意思是，“没人知道他是怎样发明这台机器的。”the way的意思相当于how；第二句的意思是，“他没有按照老师说的那样做实验。”the way 的意思相当于as。在In 1770 the room was completed the way she wanted.这句话中，the way也是as的含义。随着现代英语的发展，the way的用法已越来越普遍了。下面，我们从the way的语法作用和意义等方面做一考查和分析： 一、the way作先行词，后接定语从句 以下3种表达都是正确的。例如：“我喜欢她笑的样子。” 1. the way+ in which +从句 I like the way in which she smiles. 2. the way+ that +从句 I like the way that she smiles. 3. the way + 从句(省略了in which或that) I like the way she smiles. 又如：“火灾如何发生的，有好几种说法。” 1. There were several theories about the way in which the fire started. 2. There were several theories about the way that the fire started.
way 的用法 【语境展示】 1. Now I’ll show you how to do the experiment in a different way. 下面我来演示如何用一种不同的方法做这个实验。 2. The teacher had a strange way to make his classes lively and interesting. 这位老师有种奇怪的办法让他的课生动有趣。 3. Can you tell me the best way of working out this problem? 你能告诉我算出这道题的最好方法吗？ 4. I don’t know the way (that / in which) he helped her out. 我不知道他用什么方法帮助她摆脱困境的。 5. The way (that / which) he talked about to solve the problem was difficult to understand. 他所谈到的解决这个问题的方法难以理解。 6. I don’t like the way that / which is being widely used for saving water. 我不喜欢这种正在被广泛使用的节水方法。 7. They did not do it the way we do now. 他们以前的做法和我们现在不一样。 【归纳总结】 ●way作“方法，方式”讲时，如表示“以……方式”，前面常加介词in。如例1； ●way作“方法，方式”讲时，其后可接不定式to do sth.，也可接of doing sth. 作定语，表示做某事的方法。如例2，例3；
t h e-w a y-的用法
The way 的用法 "the way+从句"结构在英语教科书中出现的频率较高, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或 in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 一.在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮.
way的用法总结大全 way的用法你知道多少，今天给大家带来way的用法，希望能够帮助到大家，下面就和大家分享，来欣赏一下吧。 way的用法总结大全 way的意思 n. 道路,方法,方向,某方面 adv. 远远地，大大地 way用法 way可以用作名词 way的基本意思是“路,道,街,径”,一般用来指具体的“路,道路”,也可指通向某地的“方向”“路线”或做某事所采用的手段,即“方式,方法”。way还可指“习俗,作风”“距离”“附近,周围”“某方面”等。 way作“方法,方式,手段”解时,前面常加介词in。如果way前有this, that等限定词,介词可省略,但如果放在句首,介词则不可省略。
way作“方式,方法”解时,其后可接of v -ing或to- v 作定语,也可接定语从句,引导从句的关系代词或关系副词常可省略。 way用作名词的用法例句 I am on my way to the grocery store.我正在去杂货店的路上。 We lost the way in the dark.我们在黑夜中迷路了。 He asked me the way to London.他问我去伦敦的路。 way可以用作副词 way用作副词时意思是“远远地,大大地”,通常指在程度或距离上有一定的差距。 way back表示“很久以前”。 way用作副词的用法例句 It seems like Im always way too busy with work.我工作总是太忙了。 His ideas were way ahead of his time.他的思想远远超越了他那个时代。 She finished the race way ahead of the other runners.她第一个跑到终点,远远领先于其他选手。 way用法例句
t h e_w a y的用法大全
The way 在the way+从句中, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或 in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 如果怕弄混淆，下面的可以不看了 另外，在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮. the way=according to the way/judging from the way 4)The way you answer the qquestions, you must be an excellent student. 从你回答就知道,你是一个优秀的学生. 5)The way most people look at you, you'd think a trashman was a monster. 从大多数人看你的目光中,你就知道垃圾工在他们眼里是怪物. the way=how/how much 6)I know where you are from by the way you pronounce my name. 从你叫我名字的音调中,我知道你哪里人. 7)No one can imaine the way he misses her. 人们很想想象他是多么想念她. the way=because 8) No wonder that girls looks down upon me, the way you encourage her. 难怪那姑娘看不起我, 原来是你怂恿的
The way 的用法 "the way+从句"结构在英语教科书中出现的频率较高, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 一.在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮.
the way=according to the way/judging from the way 4)The way you answer the qquestions, you must be an excellent student. 从你回答就知道,你是一个优秀的学生. 5)The way most people look at you, you'd think a trashman was a monster. 从大多数人看你的目光中,你就知道垃圾工在他们眼里是怪物. the way=how/how much 6)I know where you are from by the way you pronounce my name. 从你叫我名字的音调中,我知道你哪里人. 7)No one can imaine the way he misses her. 人们很想想象他是多么想念她. the way=because 8) No wonder that girls looks down upon me, the way you encourage her. 难怪那姑娘看不起我, 原来是你怂恿的 the way =while/when(表示对比) 9)From that day on, they walked into the classroom carrying defeat on their shoulders the way other students carried textbooks under their arms. 从那天起,其他同学是夹着书本来上课,而他们却带着"失败"的思想负担来上课.
The way的用法及其含义（三） 三、the way的语义 1. the way=as（像） Please do it the way I’ve told you.请按照我告诉你的那样做。 I'm talking to you just the way I'd talk to a boy of my own.我和你说话就像和自己孩子说话一样。 Plant need water the way they need sun light. 植物需要水就像它们需要阳光一样。 2. the way=how（怎样，多么） No one can imagine the way he misses her.没人能够想象出他是多么想念她！ I want to find out the way a volcano has formed.我想弄清楚火山是怎样形成的。 He was filled with anger at the way he had been treated.他因遭受如此待遇而怒火满腔。That’s the way she speaks.她就是那样讲话的。 3. the way=according as （根据） The way you answer the questions, you must be an excellent student.从你回答问题来看，你一定是名优秀的学生。 The way most people look at you, you'd think a trash man was a monster.从大多数人看你的目光中,你就知道垃圾工在他们眼里是怪物。 The way I look at it, it’s not what you do that matters so much.依我看，重要的并不是你做什么。 I might have been his son the way he talked.根据他说话的样子，好像我是他的儿子一样。One would think these men owned the earth the way they behave.他们这样行动，人家竟会以为他们是地球的主人。
一．Way：“方式”、“方法” 1.表示用某种方法或按某种方式 Do it (in) your own way. Please do not talk (in) that way. 2.表示做某事的方式或方法 It’s the best way of studying [to study] English.。 There are different ways to do [of doing] it. 3.其后通常可直接跟一个定语从句(不用任何引导词)，也可跟由that 或in which 引导的定语从句 正：I don’t like the way he spoke. I don’t like the way that he spoke. I don’t like the way in which he spoke.误：I don’t like the way how he spoke. 4. the way 的从句 That’s the way (=how) he spoke. I know where you are from by the way you pronounce my name. That was the way minority nationalities were treated in old China. Nobody else loves you the way(=as) I do. He did not do it the way his friend did. 二．固定搭配 1. In a/one way：In a way he was right. 2. In the way /get in one’s way I'm afraid your car is in the way， If you are not going to help，at least don't get in the way. You'll have to move－you're in my way. 3. in no way Theory can in no way be separated from practice. 4. On the way (to……) Let’s wait a few moments. He is on the way Spring is on the way. Radio forecasts said a sixth-grade wind was on the way. She has two children with another one on the way. 5. By the way By the way，do you know where Mary lives? 6. By way of Learn English by way of watching US TV series. 8. under way 1. Elbow one’s way He elbowed his way to the front of the queue. 2. shoulder one’s way 3. feel one‘s way 摸索着向前走；We couldn’t see anything in the cave, so we had to feel our way out 4. fight/force one’s way 突破。。。而前进The surrounded soldiers fought their way out. 5.. push/thrust one‘s way（在人群中）挤出一条路He pushed his way through the crowd. 6. wind one’s way 蜿蜒前进 7. lead the way 带路，领路；示范 8. lose one‘s way 迷失方向 9. clear the way 排除障碍，开路迷路 10. make one’s way 前进，行进The team slowly made their way through the jungle.
在the way+从句中, the way 是先行词, 其后是定语从句.它有三种表达形式:1) the way+that 2)the way+ in which 3)the way + 从句(省略了that或in which),在通常情况下, 用in which 引导的定语从句最为正式,用that的次之,而省略了关系代词that 或in which 的, 反而显得更自然,最为常用.如下面三句话所示,其意义相同. I like the way in which he talks. I like the way that he talks. I like the way he talks. 如果怕弄混淆，下面的可以不看了 另外，在当代美国英语中,the way用作为副词的对格,"the way+从句"实际上相当于一个状语从句来修饰全句. the way=as 1)I'm talking to you just the way I'd talk to a boy of my own. 我和你说话就象和自己孩子说话一样. 2)He did not do it the way his friend did. 他没有象他朋友那样去做此事. 3)Most fruits are naturally sweet and we can eat them just the way they are ----all we have to do is clean or peel them . 大部分水果天然甜润,可以直接食用,我们只需要把他们清洗一下或去皮. the way=according to the way/judging from the way 4)The way you answer the qquestions, you must be an excellent student. 从你回答就知道,你是一个优秀的学生. 5)The way most people look at you, you'd think a trashman was a monster. 从大多数人看你的目光中,你就知道垃圾工在他们眼里是怪物. the way=how/how much 6)I know where you are from by the way you pronounce my name. 从你叫我名字的音调中,我知道你哪里人. 7)No one can imaine the way he misses her. 人们很想想象他是多么想念她. the way=because 8) No wonder that girls looks down upon me, the way you encourage her. 难怪那姑娘看不起我, 原来是你怂恿的 the way =while/when(表示对比) 9)From that day on, they walked into the classroom carrying defeat on their shoulders the way other students carried textbooks under their arms.
“the way+从句”结构的意义及用法 首先让我们来看下面这个句子： Read the following passage and talk about it with your classmates. Try to tell what you think of Tom and of the way the children treated him. 在这个句子中，the way是先行词，后面是省略了关系副词that 或in which的定语从句。 下面我们将叙述“the way+从句”结构的用法。 1．the way之后，引导定语从句的关系词是that而不是how,因此，<<现代英语惯用法词典>>中所给出的下面两个句子是错误的：This is the way how it happened. This is the way how he always treats me. 2. 在正式语体中，that可被in which所代替；在非正式语体中，that则往往省略。由此我们得到the way后接定语从句时的三种模式：1) the way +that-从句2) the way +in which-从句3) the way +从句 例如：The way(in which ,that) these comrades look at problems is wrong.这些同志看问题的方法不对。
The way(that ,in which)you’re doing it is completely crazy.你这么个干法，简直发疯。 We admired him for the way in which he faces difficulties. Wallace and Darwin greed on the way in which different forms of life had begun.华莱士和达尔文对不同类型的生物是如何起源的持相同的观点。 This is the way (that) he did it. I liked the way (that) she organized the meeting. 3.the way(that)有时可以与how(作“如何”解)通用。例如： That’s the way (that) she spoke. = That’s how she spoke. I should like to know the way/how you learned to master the fundamental technique within so short a time. 4．the way的其它用法：以上我们讲的都是用作先行词的the way，下面我们将叙述它的一些用法。
定冠词the的12种用法 定冠词the 的12 种用法，全知道?快来一起学习吧。下面就和大家分享，来欣赏一下吧。 定冠词the 的12 种用法，全知道? 定冠词the用在各种名词前面，目的是对这个名词做个记号，表示它的特指属性。所以在词汇表中，定冠词the 的词义是“这个，那个，这些，那些”，可见，the 即可以放在可数名词前，也可以修饰不可数名词，the 后面的名词可以是单数，也可以是复数。 定冠词的基本用法： (1) 表示对某人、某物进行特指，所谓的特指就是“不是别的，就是那个!”如： The girl with a red cap is Susan. 戴了个红帽子的女孩是苏珊。 (2) 一旦用到the，表示谈话的俩人都知道说的谁、说的啥。如：
The dog is sick. 狗狗病了。(双方都知道是哪一只狗) (3) 前面提到过的，后文又提到。如： There is a cat in the tree.Thecat is black. 树上有一只猫，猫是黑色的。 (4) 表示世界上唯一的事物。如： The Great Wall is a wonder.万里长城是个奇迹。(5) 方位名词前。如： thenorth of the Yangtze River 长江以北地区 (6) 在序数词和形容词最高级的前面。如： Who is the first?谁第一个? Sam is the tallest.山姆最高。 但是不能认为，最高级前必须加the，如： My best friend. 我最好的朋友。 (7) 在乐器前。如： play the flute 吹笛子
Way用法 A:I think you should phone Jenny and say sorry to her. B:_______. It was her fault. A. No way B. Not possible C. No chance D. Not at all 说明：正确答案是A. No way，意思是“别想！没门！决不！” 我认为你应该打电话给珍妮并向她道歉。 没门！这是她的错。 再看两个关于no way的例句： （1）Give up our tea break? NO way! 让我们放弃喝茶的休息时间？没门儿！ （2）No way will I go on working for that boss. 我决不再给那个老板干了。 way一词含义丰富，由它构成的短语用法也很灵活。为了便于同学们掌握和用好它，现结合实例将其用法归纳如下： 一、way的含义 1. 路线
He asked me the way to London. 他问我去伦敦的路。 We had to pick our way along the muddy track. 我们不得不在泥泞的小道上择路而行。 2. （沿某）方向 Look this way, please. 请往这边看。 Kindly step this way, ladies and gentlemen. 女士们、先生们，请这边走。 Look both ways before crossing the road. 过马路前向两边看一看。 Make sure that the sign is right way up. 一定要把符号的上下弄对。 3. 道、路、街，常用以构成复合词 a highway（公路），a waterway（水路），a railway（铁路），wayside（路边）
way/time的特殊用法 1、当先行词是way意思为”方式.方法”的时候,引导定语从句的关系词有下列3种形式： Way在从句中做宾语 The way that / which he explained to us is quite simple. Way在从句中做状语 The way t hat /in which he explained the sentence to us is quite simple. 2、当先行词是time时,若time表示次数时,应用关系代词that引导定语从句,that可以省略; 若time表示”一段时间”讲时,应用关系副词when或介词at/during + which引导定语从句 1.Is this factory _______ we visited last year? 2.Is this the factory-------we visited last year? A. where B in which C the one D which 3. This is the last time _________ I shall give you a lesson. A. when B that C which D in which 4.I don’t like the way ________ you laugh at her. A . that B on which C which D as 5.He didn’t understand the wa y ________ I worked out the problem. A which B in which C where D what 6.I could hardly remember how many times----I’ve failed. A that B which C in which D when 7.This is the second time--------the president has visited the country. A which B where C that D in which 8.This was at a time------there were no televisions, no computers or radios. A what B when C which D that