1.   Introduction

Tree species replacement, introducing needle species to the broad-leaf forests, and stand tending technologies were used to improve the quality of the degraded polar plantation. These measures are based on the thought of matching trees with site conditions after the declining mechanisms of poplar plantation were analyzed. The technology is suitable for the restoration of the degraded poplar plantation in hilly and mountainous areas in the northern North China.

2.   Applicable conditions

2.1   The main use(s) of the technology

√ increase production(crop, fodder, wood/ fibre, water, energy)

√ reduce, prevent, restore land degradation (soil, water, vegetation)

√ conserve ecosystem

□ preserve/ improve biodiversity

□ reduce risk of disasters (e.g. droughts, floods, landslides)

√ adapt to climate change/ extremes and its impacts (e.g. resilience to droughts, storms)

□ mitigate climate change and its impacts (e.g. through carbon sequestration)

□ create economic benefits (e.g. increase income/ employment opportunities)

√ create social benefits (e.g. reduce conflicts on natural resources, support marginalized groups)

□ other purposes (specify): ……………………………………………………………………………………………

2.2   Types of degraded land to which the technology is applicable

□ Semi-fixed sandy land

□ Shifting sandy land

□ Desertified grassland

□ Saline-alkali grassland

□ Active wind-erosion pit

√ Degraded forestland

□ Desertified cultivated land

□ Other types

2.3   The climatic conditions to which the technology is applicable

1   

Climate zones	Temperate semi-arid zone, temperate sub-humid zone
Average annual precipitation/mm	350-450mm	Average annual evaporation/mm	1400-1900mm
Average annual temperature/℃	3-5℃	Maximum temperature/℃	17-22℃
Minimum temperature/℃	-13-19℃	Average annual wind speed/ m/s	4.3m/s
Note: Precipitation, evaporation, air temperature and wind speed in the table are average values over the 1980-2010 period. The climatic data were obtained from local national weather stations.

下载: 导出CSV 

| 显示表格

2.4   The origin of the technology

2   

Province	County	Township	Climate zones	Longitude	Latitude	Elevation/m
Hebei Province	Zhangbei County	Xiaoertai Township	North temperate semi-arid region	114.86°E	41.18°N	2128

下载: 导出CSV 

| 显示表格

3.   Site conditions suitable for the technology

3  Topographical conditions

Elevation	Topography	Slope gradient	Slope direction	Slope position
□ < 100 m	■ Flat lands	■ Flat (0-5%)	□ Sunny	□ Up
□ 101-500 m	□ Hillside	□ Gentle (6-15%)	□ Shady	□ Middle
□ 501-1, 000 m	□ Hilly slopes	□ Slope (16-25%)	□ Half-sunny	□ Down
■ 1, 001-1, 500 m	□ Slopes	□ Steep (26-35%)	□ Half-shady
■ 1, 501-2, 000 m	□ Valley floor
□ 2, 001-2, 500 m	□ Sand dunes
□ 2501-3, 000 m	□ Flat sandy land
	■ Cultivated land that slopes gently

下载: 导出CSV 

| 显示表格

4  Soil condition

Soil types	Soil texture	Effective soil layer thickness	Organic matter content of surface soils	Soil hardness	Soil gravel content
■ Aeolian sandy soil	□ Sandy soil	□ 0-20 cm	□ High (> 3%)	□ High	■ Light gravelly soil(1-5%)
■ Calcium chestnut soil	■ Sandy loamy soil	□ 20-50 cm	■ Medium (1-3%)	■ Medium	■ Medium gravelly soil(5-10%)
□ Brown calcium soil	□ Loamy soil	□ 50-100 cm	■ Low (< 1%)	■ Low	■ Gravelly soil(10-30%)
□ Cinnamon soil	□ Clay	■ 100-200 cm			□ Light gravel(30-50%)
□ Saline-alkali soil		■ > 200 cm			□ Medium gravel(50-70%)
□ Others:					□ Heavy gravel soil(> 70%)

下载: 导出CSV 

| 显示表格

5  Vegetation status

Vegetation types	Community coverage	Vegetation degradation status
■ Planted forest: (Populus euphratica)	□ < 5%	■ Light
□ Sandy vegetation: (what kind of community)	■ 5-15%	□ Moderate
□ Bush: (what kind of community)	■ 15-25%	□ Severe
□ Grassland: (Temperate meadow grassland)	□ 25-40%	■ Artificial forest with dead treetops
□Meadow: (what kind of community)	□ > 40%	□ Artificial forest with dead trees
□Others:

下载: 导出CSV 

| 显示表格

6  Groundwater status

Average buried depth
□ < 1 m
□ 1-3 m
□ 3-5 m
□ 5-10 m
■ > 10 m

下载: 导出CSV 

| 显示表格

4.   Technical contents

7  For specific technologies, please fill in the relevant information by selecting the technology category below.

Technological flow	The main points of the technology	Season/month of implementation
1. Land preparation	Hole preparation. Trees: 60 × 60 × 60 cm Shrubs: 30 × 30 × 30 cm	Spring (April-May)
2. Pruning	Manual pruning was carried out to avoid excessive competition in stands after density adjustment. The pruning starts from the base of the stubble, remove all extra branches. Strong trees with good site conditions, ideal height, and thickness can be pruned once for all. Less developed trees with poor site conditions could be pruned twice. The first time, only small branches at the base could be moved and kept the horizontal branches. Then, removed all lower horizontal branches in the following year after the new sprouts having new lateral branches elongated.
3. Selective felling	Based on the analysis of the height and DBH (diameter at breast height) of the degraded stands, trees with poor growth situation were thinned to retain a reasonable density.
4. Regeneration and rejuvenation	Coniferous species (e.g. pinus sylvestris) seedlings should be 100 cm high with soil balled roots. Shrub seedlings should be 0.4 cm in diameter with bare roots. Stand density after regeneration: 650-750 plants/hm2, coverage: 30-40% with shrub cover about 40%. For undegraded and lightly degraded stands, the main measure should be to strengthen the management and avoid human disturbance. Based on the thought of matching trees with site conditions, arbors such as poplar, elm, pinus sylvestris, larch, and shrubs such as Hippophae rhamnose, apricot, and Caragana microphylla could be replanted.	Spring (May)
5. Nurturing management	Enclosure to reserve native species tree species.
6. Others	None
Appendix or attachment (if there are relevant technical parameters indicators, you can add the schedule or annex information here)

下载: 导出CSV 

| 显示表格

5.   Technological cost

8   

Labor cost: 1, 500 -2, 000 RMB / ha
Machinery cost: 0 RMB /ha
Material cost: 500-1500 RMB / ha
Water cost (if irrigation was required): 0
Total cost: 2000-3500 RMB / ha

下载: 导出CSV 

| 显示表格

6.   Demonstrations

Comparison before and after the technology implementation.

1  Pictures before (2016) and after (2018) the technology implementation in a degraded poplar plantation in Xiaoertai Township, Zhangbei County

下载: 全尺寸图片 幻灯片