| The Conversion Programme (Converting Slope Farmland to Forest) has been implemented forabout eight years in China. The programme has made great contributions to environmentalimprovement in the country.Bamboo is one of the major forest resources in southern and southwestern China. Due tobamboo's advantages in its biological, ecological and economic values, bamboo species havebeen selected as important species for the Conversion Programme. Although bamboo resourceshave great social and economic value and potential, which have been reported by manyresearchers, however, few researches have reported on quantifying ecological benefits. Tounderstand and discover ecological benefits of the bamboo plantation in the programme, a casestudy has been done in the Conversion Programme area in Minzu village, Chishui region ofGuizhou province since 2004, to quantitatively monitor the performance of bamboo(Dendrocalamus farinosus (Keng et Keng f.) Chia et H. L. Fung) plantation in its capacity ofwater and soil conservation, restoring biodiversity, improving soil, adjusting microclimate,with a comparison study to slope farmland. Based on the field monitoring data, ecologicalperformance and comprehensive environmental benefits of the bamboo plantation in theprogramme have been analyzed and recommendations to improve the programme have beenmade as conclusions of the study. The major findings of the study are summarized below:1. Capacity of holding water of the bamboo stand1.1 During the period of observation, the total of through rainfall is 251.51mm, while therainfall is 282.16mm outside forest. As a result, the rate of through rainfall is 89.14％. The totalstem flow of bamboo forest is 4.44mm, thus the total canopy interception is 26.21mm, and therate of canopy interception is 9.29％.1.2 The total mass of the litter is 14.5t·hm-2, dry mass of un-decomposed layer is 3.87t·hm-2,semi-decomposed layer is 8.0t·hm-2, and the maximum water holdup of the decomposed is27.54 t·hm-2, which is equal to a rainfall in depth of 2.4mm to 3.3mm, occupying14.46～19.88％of the total rainfall.1.3 Supposed that the thickness of soil is approximately 1.0m in the experimental forest land, the water storage capacity of the soil is 899 t·hm-2, while it is 485 t·hm-2 in slope farmland. Thewater storage capacity per hectare bamboo forest soil is approximately 414t, which is 1.85times of that of slope farmland.2. Capacity of conserving soil and water2.1 During the period of observation, the amount of each runoff in the bamboo forest isbetween 0.49mm and 3.17mm, and the amount of average runoff is 1.4mm, which respectivelyare 2.6％～18.4％and 5.9％of the total amount of the rainfall. In farmland as a controlobservation, the amount of average runoff is between 0.55mm～3.95mm, and the average is1.65mm, which respectively are 2.2％～20.5％and 7.0％of the total amount of the rainfall. Theamount of average runoff in the bamboo forests compared to the slope farmlands is reduced by15.7％.2.2 The average soil erosion quantity in forestland is 0.046 t·hm-2, while the one in farmland is0.21t·hm-2. Soil erosion quantity in farmland is about 4.6 times of that in the bamboo forestland;consequently, average soil erosion quantity is reduced by 78.56％.3. Restoring biodiversityThere are 19 herbal species and 4 vine species in the bamboo plantations, which are theGramineae, Compositae, Urticaceae, Dryopteridaceae, Plantaginaceae, Scrophulariaceae andMyrsinaceae. As a result, we found out that the species richness is greatly improved in thebamboo plantation compared to farming lands.4. The observed results of improving soil4.1 The average soil moisture content of bamboo forest is 19.47％, while it in farmland is18.57％. Average soil moisture content in farmland is higher than in the bamboo forestland by0.9％, being 4.8％of the amount of the forestland. The results show that the soil bulk density is1.47g/cm3, and total porosity is 44.53capillary porosity is 35.54％, non-capillary porosity is8.99％, which are more than in farmland by 7.28％and 6.34％and 11.13％. The originalosmosis value of the soil in the bamboo forests is as 5 times higher as that in the farmland, andthe stable osmosis value of the soil in the bamboo forests is as 4.9 times higher as that in thefarmland. Both original osmosis and stable osmosis in foresfland are higher than those infarmland.4.2 The amount of the organic matter and total N and total P in bamboo forestland is 135％and 111％and 144％respectively higher than in those in farmland, and the quantity of available Nand available P and available K in bamboo forestland is also higher than in those in farmlandby 112％and 176％and 370％. The quantity of total K in bamboo forest.land and farmland are8.gg/kg and 10.6g/kg, forestland is less than farmland, for the different way of being absorbedby the plant, but the quantity of available K in bamboo forestland is higher than in farmland,and the K element in available nutrient is increasing. The pH value of forestland is 5.21, thefarmland is 4.95, so the CFBF can reduce the soil acidity5. Microelimate5.1 Average soil temperature in bamboo forestland is 22.87℃, and the daily variation aresmaller (coefficient of variation(CV)=0.079) comparing to those in slope farmland whereaverage soil temperature is 27.42℃, coefficient of variation(CV)=0.146. Average soiltemperature in bamboo foresfland is lower 4.55℃than it in farmland.5.2 The average maximum and minimum air temperatures in bamboo forests are 29.3℃and19℃, while there are 36.6℃and 19.3℃in farmland. The diurnal range of maximum airtemperature in forests and farmland is 10.9℃. Average air temperature in bamboo forests is24.3℃, while it is 27.8℃in farmland.5.3 The relative humidity of air in bamboo forests is 89.4％, while it is 84％in farmland. Airhumidity in the morning is higher than in that at noon; average relative humidity of air at 8:00a.m. is higher than 14:00 p.m. by 19.6％, in farmland which is 19.8％. Moreover, whether in themorning and afternoon, the relative humidity of air in bamboo forests is higher than those infarmland, respectively by 5.3％and 5.5％.6. According to the experimental observation data, using the Analytic Hierarchy Process (AHP)the comprehensive ecological benefits of the bamboo plantations on holding water, conservingsoil and water, restoring biodiversity, improving soil, and adjusting microclimate are analyzed.The results show that the benefits of the bamboo forests and farmland on holding water,conserving soil and water, restoring biodiversity, improving soil, adjusting microclimate arevery different. The comprehensive ecological benefits of the bamboo plantation is much betterthan that in the farmland, and the benefits of bamboo plantation on holding water, conservingsoil and water, restoring biodiversity, improving soil, and adjusting rnicroclimate are alsohigher than those in the farmlands. In summary, in the region with purple soil, such as Chishui region and the other areas along themiddle and upper reaches of the Yangtze River, where serious water and soil erosion happen,the bamboo plantations in the Conversion Programme performs very well in ecologicalbenefits. Dendrocalamus farinosus plantation demonstrates an excellent example forimplementing the Conversion Programme in similar areas.
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