| In order to understand the species and community of birds and ecosystem dynamic change mechanism, the standardization of research methods and long-term observation and research is necessary; monitoring is an effective way to evaluate the progress of biodiversity conservation. Because of the special geographical position and abundant bird resources in Guangxi, it is important to carry out long-term monitoring of birds in this region, especially for breeding bird’s (including summer migratory and resident birds) monitoring, it is related to the survival and reproduction of birds. The long-term monitoring of wild bird diversity of birds is the core part of bird research, protection, management and sustainable utilization of resources. There is still a lack of long-term accumulation of bird diversity dynamic data in our country.Through monitoring the ten monitoring stations in guangxi of summer breeding bird for a long sequence, The composition and distribution pattern of breeding birds, the status of habitat reproduction, the trend of population quantity dynamic evolution and the main threat factors were studied and assess the effects of habitat varied from year to year changes in bird populations, in order to provide a theoretical basis for bird conservation and management decisions, and improve the bird diversity protection decisions in guangxi more scientific.From 2011 to 2015, the breeding birds and communities in Guangxi were monitored by line transect method for 5 consecutive years. According to the natural terrain and the geographical division of Guangxi, the layout of the lines were divided into 5 areas, whichs are the north and the south of Guangxi, the southwest of Guangxi, the central area of Guangxi and the coastal area. Each area has 2 monitoring points, each point has 2 lines, Each sample line was repeated 1 times over the same period, a total of 40 times survey one year. Monitoring in the early morning 05:30-09:30 and evening 17:00-19:00, because birds are active in that time period.The monitoring results of 5 years showed that:(1) A total of 172 species of breeding birds were recorded.in 5 years, belonging to 13 orders and 45 families, which accounted for 25.04% of the Guangxi birds. One specie founded was National Class One protection bird, it was Mrs. Hume’s Pheasant; 16 species were National Class TWO protection bird, they were Lesser Coucal, Greater Coucal, lack-winged Kite, Long-tailed Broadbill and so on. Passeriformes Birds were the largest group, there were 101 species, accounting for 58.72%.84 pecies are Oriental species, accounting for 53.85%; 72 were widely distributed species, accounting for 46.15%, no Palaearctic birds. Residence type composition is complex, but in general the resident birds were the main component of the bird community. In terms of quantity, Bulbul, swallows, sparrows, egrets, red-whiskered bulbul is the dominant species in Guangxi during the five-year survey of breeding birds.(2)The trend of development of Guangxi breeding bird communities for species and quantity increased year by year, it indicated that the bird population had been well protected and propagated.99 species and 2135 numbers of breeding birds were recorded in 2011, belonging to lOorders and 38families; 109species and 3020numbers of birds were recorded in 2012, belonging to 1 lorders and 41families; 107 species and 4214numbers of birds were recorded in 2013, belonging to lOorders and 40families; 111 species and 4416 numbers of birds were recorded in 2014, belonging to 12 orders and 37 families; 122 species and 5139 numbers of birds were recorded in 2015, belonging to 12 orders and 39 families. The average annual increase in the number of 600, the average annual growth rate was 23.88%. From 2011 to 2013, the growth rate was relatively fast, the number of population growth from 2013 to 2015 was slow, this was related to the long-term precipitation over the last two years in Guangxi. Excessive rainfall in the rainy season resulted in adverse natural climatic conditions during the breeding birds brood, the chick’s growth environment deteriorates, due to the low survival rate of chicks and slow population growth. Bird’s diversity index was higher and the difference was small in all years, it is 3.68-3.87, the rank was 2012>2011> 2013>2014>2015. The evenness index differences were also small, which were 0.76 to 0.83, the rank was2011>2012>2014> 2013>2015. Combining diversity index and evenness index results show that, Bird diversity was abundant in all year. Although the number of species and the number of birds recorded in 2015 were the most, but the bird diversity index and evenness index were the smallest, this is related to the rapid growth of many dominant species and large number of species concentrated.(3) The similarity coefficient between the 5 regions is relatively low, and there were regional differences. The rank of the number of species was as follow:Southwest Guangxi> North Guangxi> South of Guangxi> Coast>Middle part of Guangxi. The bird diversity in the Southwest of Guangxi, the North and the South of Guangxi were better than that of the Middle part and the coastal area, Bird diversity index and evenness index were higher, and species are more abundant and distribute evenly. In southwest of Guangxi Regional bird species diversity index and evenness index was the highest, where was an important area for breeding bird communities.(4) 6 kinds of habitats of bird species, diversity index and evenness index were different. The rank of the number of species was as follow:Tree forest> shrub> freshwater body> farmland> residential area> coastal area. The tree forest, shrub, farmland and fresh water had more bird species, diversity index and evenness index were also higher, these four communities had higher bird diversity at the species level, and the community structure is fairly stable. The index of residential and coastal habitats were all low, the birds in this habitat are mostly clusters, due to the strong intensity of human disturbance, the distribution of species is greatly affected, and the distribution is not balanced.(5) Human disturbance was the most serious in the coastal areas among the five monitoring areas. Due to the rise of real estate, land reclamation carried out serious, part of the breeding habitat area was destroyed for building high-rise buildings and roads, making the fragmentation of bird habitats became more and more serious, the distribution area were shrinking, the quantities of species were declining continuous, bird diversity were lost, so coastal areas should be the focus of attention and protection in the future. |
