Analysis Of Characteristics Of Plant Functionalgroups And Response For Landscape Pattern At Multi-scale In Different Land-form Areas

In this study, Gongyi city of Henan Province, a typical agricultural region in the middle and lower reaches of the Yellow River, was taken as the study area for investigation of the plant species of seminatural habitat(namely, artificial forest, shrub and farmland) in three different physiognomy types(such as river plains, hilly ground, low-middle mountain area). Based on the plant life form,all plant species in the survey area can be classificated into different plant functional groups(PFGs). The distribution characteristics of PFGs are analyzed in different land-form areas and different habitats. Then we examine whether the present distributions of PFGs of plant species in the semi-natural habitat established on different land-form areas are related to the past surrounding landscapes at different time periods and spatial scales, and discusse the multi-scale effects of past landscapes varied significantly among the PFGs. Research shows that the relantionship between richness of PFGs and environmental factors by multiple model reasoning method(MMI).The results show that:(1)The distribution characteristic of PFGs in different land-form areas is different. Study area with rich plant resources, after field investigations, a total of 76 such plants branch, 239 genera and 336 species. Based on the plant life form, all species are classificated into seven PFGs. In terms of functional group of species, the species richness of Annuals and biennials grasses(AG) is 14, Perennial grasses(PG) is 15, Annuals and biennials forbs(AF) is 81, Perennial forbs(PF) is 142, Shrubs and semi-shrubs(SS) is 52 and Tree Species(TS) is 32.(2)Low-middle mountain area at different time and space scales has the highest percentage of seminalnatural habitats, second is hilly ground, and the lowest is river plains. The species richness of total species and each PFGs of in different land form has significantly positive or negative correlation with seminalnatural habitat proportions at smaller spatial scales such as 250m、500m. Then the important spatial scales of surrounding landscapes were also different among the total and PFGs.The species richness of river planes landscape was correlated with seminal-natural habitat proportions in 2011, then the species richness of hilly ground and middle and low-middle mountain area is correlated with proportion of seminalnatural habitats in 1990 and 2001,the results suggested that PFGs of hilly ground and low-middle mountain area exhibit distinct time-lags in response to historical landscape change.(3) The explanation variables in hypotheses models matrix quality(H2), habitat quality(H3), matrix quality change(H4), habitat change(H5) change over scale in three different landforms. But topographyenvironmental conditions(H1) changes over without scales only reflect geographical conditions around samples in three geomorphic types. Altitude is a factor has the most significant difference in different physiognomy types; slope has increased gradually with the increase of altitude, most of slope Angle in NE and SE quadrant. As found in studies, north-facing samples were poorer in species respect to those located on south and east facing slopes, which emphasizes the role of SE quadrant grasslands on local species richness. The positive effect of distance to rivers may be mainly explained by the higher water stress existing in samples located in the flood plain, which influenced the vegetation patterns. Another reason may be related to crop land use practiced in proximity to rivers and meadows which could influence the presence of plant species in these locations. Larger distance to roads represents smaller interference.(4) For the river plain geomorphic type, species richness of AG and PG is mainly related to the H3 at all spatial scales; Species richness of AF and TS has an obvious relationship with H5 at limited spatial scales, but as scale increases, relationship with H3 becomes more significant. Species richness of PF and SS has a strong scale dependence on the landscape and environmental factors, and explaining model for different richness of different scales are varies. But Species richness of PF at all scales have no impacts from H3.For the hilly geomorphic type, species richness of AG has an obvious relationship with H2 at limited spatial scales, but as scale increases, relationship with H3 becomes more significant. Species richness of AF have no dependence on the spatial scales degree, but mainly have significantly relevance with topographical and environmental factors; species richness of PF mainly associated with the terrain environmental factors H1; Species richness of PG mainly dependent on landscape elements in stand of H1, which is environment topographic factors; for the SS, in range of 250 m and 750 m spatial landscape scales, model H2, which relationship is most significant, need to be considered only, for the rest scales, terrain-environmental factors H1 environmental factor, which have the most significant model relationships, need to be considered only; TS species richness have a relatively obvious scale dependence, mainly have close relationship with H2, H3, H5, which are related with the matrix and habitat characteristics and habitat changes, do not influenced by the terrain environment factor.For the low-middle mountain geomorphic type, species richness of AG at all spatial scales are mainly affected by H3; species richness of AF has an obvious relationship with H5 at limited spatial scales, but as scale increases, relationship with H3 becomes more significant. Species richness of PF has a strong scale dependence on the landscape and environmental factors, and explaining model for different richness of different scales are varies. Species richness of PG & TS mainly relevant with H3 and H5; but in all scales PG have no impacts from the terrain- environmental factors; the species richness of SS mainly influenced byH2 and H3.For the total species, total species richness plains mainly influenced by substrate quality and changes; species richness for hills and mountainous areas have a higher scale dependence, and changes with different landscape factors and terrain elements.Overall, species richness on the different landforms at different scales have different relevance with different models.