Plant Community Character And The Corresponding Relation With Habitats On The Habitat Of Giant Panda In The Qingling Mountains’ China

Foping Nature Reserve and Changqing Nature Reserve are the main habitats of the giantpanda in the middle range of the Qinling Mountains. The geographical position and ecologicalforest environment of this region create uniquely and richly biological resources and plantcommunities. Previous studies focused on the study of plant community traits and speciesdiversity in this habitat area, but the flora, community types, and growth status are stillunknown, therefore, the protection and operation of the giant panda habitat exists someblindness.Plant community character, distribution and the relationship with environment on thehabitat of Giant Panda in the Qinling Mountains were explored in this study. Foping NatureReserve and Changqing Nature Reserve were selected as study areas. Tow line transects wereset between the altitude of900-3071m in the field, and107standard plots (25×20m2)wereinvestigated on transects. Vegetation community, growth status and distribution environmentwere recorded and soil samples were collected in the standard plots. Based on analysis ofplots and soil data, flora characteristics, altitudinal patterns of seed plants, plant speciesdiversity, community complexity, the altitudinal pattern between species diversity andcommunity complexity and community stability evaluation were examined comprehensively.Our study was trying to explore the plant community distribution and its relationshipwith the environment in the Qinling panda habitat, so as to provide some scientific referencesand theoretical basis for habitat conservation and sustainable utilization of species diversity,vegetation restoration and reconstruction, and the artificial expansion of the giant pandaactivity areas.The results are as follows:(1) The habitat contained2031spermatophyte species from148families and694genera.Spermatophyte species accounted for59.11%of the total plant species in the QinlingMountains but only7.45%of the total plant species in China, including36endemic Chinese plant species and15protected species. There were many ancient and relict spermatophytespecies in this region, which represented a large proportion of endemic Chinese species andthose in a nationally conserved status. Tertiary relict plant species are rich in abundance andthey form an important part of plant communities in the research area, which indicates that theorigin of the flora is very ancient. Temperate genera are dominant in the area, but there is atransition from subtropical to temperate types. Thus, the research area is an importantintersection region. At the same time, the research area is also the intersection area betweenSino-Japan forest zone and Sino-Himalaya forest zone.(2) Analyzing of the altitudinal phytogeography of spermatophytes (seed plants) inQingling Mountains habbitat, the quantity of family, genus and species showed the skewnormal distribution with the increased altitude. The richest family, genus and species wereconcentrated at1200-1300m. According to the ratio of the the tropical and temperate elementsproportion, the balance point of the research area was found out. There was no vegetationsubtropical-warm temperate dividing line(floristic equilibrium point) in study area fromtheory, and the theoretical boundary for the subtropical-warm temperate zone should be at530m above the sea level, and the threshold height of tropical distribution is at2800m.(3)107standard plots were classified into44plant communities by Two-way IndicatorsSpecies Analysis (TWINSPAN). The result of ordering by Detrended Corresponding Analysis(DCA) showed that the standard plots fit to aggregation distribution and verified thescientificity of TWINSPAN. The test of significance between Detrended CanonicalCorrespondence Analysis (DCCA) and Monte Carlo that the restrictive factors of communitytype and species distribution were altitude, slope, rapidly-available phosphorus and totalphosphorus at the landscape level.(4) Different vegetation types and community types had different species diversity anddiversity of different layers had significant differences. For vegetation types, the highestdiversity was in evergreen forests and mixed deciduous forest, the lowest one was in bambooforest. For community types, the highest diversity was in Cyclobalanopsis glauca+Q. alienavar. Acuteserrata mixed forest, the lowest was in Bashania fargesii bamboo forest. Differentlayers of vegetation types and community types did not have the same sequence, because ofthe diversities of different layers had a close relationship with environment and shrub density.The diversity of tree layer was significantly correlated with the shrub layer diversity, butwasn’t related with the herb layer. Careful analysis of the relationships between speciesdiversity and environment factors explored there existed mutual restriction relationshipbetween soil, topography and species diversity. Altitude, available phosphorus and totalpotassium had significant correlation with diversity respectively. (5) The community complexity was evaluated by Huffman Coding. The complexity ofdifferent community types and layers was significantly different. The total complexity anddisorder complexity was significantly correlated with that in shrub layer. Soil and topographyfactors had significant correlation with community structure complexity, especially altitude,slope, available phosphorus, total phosphorus. Community dominance and coefficient ofvariation had the significant linear relationship with community complexity respectively.Community ordered structure complexity was higher, disordered structure complexity waslower; community dominance was higher, and community complexity was lower.(6) With increased altitude, the species diversity and complexity of plant communitiespresented a "low-high-low" pattern of skewed normal distribution. The altitude between1300and1500m was the largest region of total complexity and diversity of plant community.Community disordered structure complexity was similar to community complexity. However,Community ordered structure complexity did not have regular changes along with the altitude.Plant species diversity of the natural reserve was not only related with the altitude change, butalso had close relationship with the density of Bashania fargesii and Fargesiaqinlingensis.The species diversity and species number had improved significantly in theintersection of two bamboo groves. Correlation analysis proved community complexity andcommunity disordered structure complexity had significant linear relationship with diversityindex respectively. The correlation value between community complexity andShannon-Weiner was close to1, it means the species diversity would express the change ofcommunity complexity. Community ordered structure complexity was not correlated withevenness index, which means it could not be used as the measure method of communitycomplexity.(7) Community stability of16reprehensive and typical community types were evaluatedby subordinate function of fuzzy mathematics. The evaluation index included the regenerationof dominant species, stand qualities, diversity, community complexity, soil fertility andprotective degree. The stability order of different communities was: Tsuga chinensis>Quercus glandulifera var.brevipetiolata> Populus purdomii> Quercus aliena var.acuteserrata> Pinus armandii> Betula platyphylla> Abies fargesii> Pinus tabulaeformi+Pinus armandii>Betula albo-sinensis> Betula albo-sinensis var. septentrionalis> Larixchinensis> Pinus tabulaeformi+Quercus aliena var. acuteserrata> Pinus tabulaeformi>Quercus variabilis> Castanea mollissima> Betula luminifera.