3. Contribution to broad-leaved species cultivation:
trees and shrubs

Background: many plantations and shelterbelts in the Korqin Sandy Lands have been established by the TNSP, but most of them are pure stands with weak stability, susceptible to pests and diseases and shortened growth periods. Increased bio-diversity and the diversification of the production base through the introduction of trees other than poplars and conifers, including shrubs and fodder species, is deemed essential to the long-term stability of the productive system. Native species are thought to be better suited to increase bio-diversity, and are given priority over introduced species, if performance equals the one from exotic species. However, due to the severe environmental conditions in the Korqin, and the relative lack of viable alternatives, each additional species that can be planted and that survives and grows, be it native or exotic, is an important contribution.

Activities range from information gathering and initial screening trials through to more detailed provenance collection and testing with species which have already shown their value such as the native Ulmus and Salix species.

When dealing with new species, the very process of seed collection, introduction, nursery production and planting-out results in selection through the failure of weaker individuals which cannot survive their new

conditions. Those individuals, which do survive, are more adapted to the new location and are planted in secure locations to ensure their survival for future use. Planting is done in blocks to facilitate cross- pollination and fertile seed production.

Several species, that were common in the past, are becoming very rare in the Korqin Sandy Lands, and it is thought that their conservation is not only necessary out of historical reasons, but that their genetic material holds promise for future development. These species have been subjected to years of negative selection, so that the remaining individuals are of bad form and slow growth.

Realizations by the Project:

• nursery seedling production of over 40 different broad-leaved species, both native (including local seed-recollection) and introduced trees and shrubs, distributed over 2 Branches

• out-planting to the field of ove 20 different broadleaved species

3. 1 Nursery Trials

Native broadleaved species

In 1998, seeds from nine broadleaved species was recollected from the Daqinggou Valley and seedlings raised at the Xinglongzhao Forest Farm. Table 3.1.1 lists the species and the seed treatments applied.

Table 3.1.1 : Species recollected from Daqingguo Nature Reserve

and seed-treatments applied

Species	Seed treatments applied
Acer mono	Soaked for 24 h in water (initially at 50°C), followed by statification for 6 days in the wet sand
Celastrus articulatus	Soakedg for 24 h in water (initially at 40°C) followed by statification for 12 days in the wet sand
Celtis bungeana	Soakedg for 24 h in water (initially at 70°C) followed by statification for 7 days in the wet sand
Armeniaca sibirica	Covered over winter with sand (sown to germinated the following year in spring)
Ulmus macrocarpa	No treatment, direct sowing
Morus alba	Soaked for 12 h in water (initially at 50°C), then washed in cold water and stratified in wet sand, then wash daily with water until germination, then planted.
Quercus mongolica	Covered with sand over winter (sown to germinated the following year in spring)
Rhamnus parvifolius	Soaked for 48 h in water (initially at 50?), then stratified
Hemiptelea davidii	No special treatment applied

Introduced broadleaved species

In November 1997, after a studytour, the Project brought broadleaf seeds from Canada. (See Table 3.1.2)

Table 3.1.2 : Seedling Treatment Methods applied to introduced broadleaved species

Botanical Name	Methods
Fraxinus americana	Soaking in water at 50°C for 48 hours, followed by stratification in humid sand for 10 days
Ulmus davidiana var. Japonica	Soaking in water at 40°C for 24 hours: results were not convincing
Caragana arborescens	Immersion of seeds in water at 70°C, followed by immersion in cold water; previous process to be repeated twice; then soak seeds in warm water for 11 days, change the water dayly. Finally, after soaking in water at 40°C for 24 hours, stratify in humid sand for 3 days.

3. 2 Afforestation Trials

Baotuyingzi

In April 1999, seeds of seven broadleaved species, recollected by the Xinglongzhao Forest Farm in the Daqingguo Valley, were planted in moving dunes at Baotuyingzi. After the two-year long drought from 1999 to 2001, the plants of Morus alba, Acer mono and Armeniaca sibirica survived in large numbers, indicating that indigenous species had a strong adaptability and could grow in barren sandy soil and dry conditions.

Plantation at Xinglongzhao

Similar results (with the exception of Acer mono) were obtained from a trial plantation of fifteen broadleaves done in April 2000 at the periphery of the nursery at the Xinglongzhao Forest Farm. When in October 2000, 259 plants of 15 species survived, in August 2001 only 156 plants of 10 species survived. The survival of local species like Morus alba and Celastrus articulatus was relatively good; among the newly introduced trees, only Rhus trilobata and Fraxinus americana survived better. (See Table 3.2.2).

Table 3.2.1 : Survival rates of broadleaved species (established April 2000)

Botanical Names	Out-planted number	Surviving Plants as at October 2000	Surviving Plants as at August 2001
Shepherdia argentea	13	12	5
Berberis sp.	3	1	0
Cydonia japonica	3	1	0
Rosa ssp.	9	5	5
Quercus mongolica	17	3	0
Ulmus macrocarpa	11	3	1
Celtis bungeana	7	6	4
Morus alba	32	24	15
M. mongolica	40	35	24
Fraxinus pennsylvanica	70	50	40
Acer mono	36	25	0
Rhus trilobata	36	22	19
Celastrus articulatus	26	23	10
Rhamnus parvifolius	24	9	0
Robinia pseudo-acacia	50	40	33

Afforestation Trials in Section Three of the Xinglongzhao Forest Farm

In April 2001, containerised and bare-rooted nursery stock from 1998 and 1999 production seasons was used at the Xinglongzhao Forest Farm in an afforestation trial. A total of 14 species was used. During planting, 0.5 kg water-preserving agent and 10 l water was applied per plant. No further irrigation was given. The survival rate (July 2001) was relatively good, taken into consideration that soil humidity over June and July (normally rainy months) was reduced to only 2%. This shows that Morus alba, Armeniaca sibirica, Fraxinus americana, Ulmus spp. and Acer mono have a high drought resistance. (See Table 3.2.3).

Table 3.2.2 : Comparisson per species of survival rates of containerised vs. bare-rooted stock.
(July 2001)

Provenance trials with Robinia pseudoacacia introduced from North America

In 1998, seeds of 33 provenances of R. pseudoacacia were introduced from North America. A provenance trial was established in 1999 at the Liaoning Sand Fixation Research Institute with 26 surviving provenances.At the beginning of July, 2001, only 27 plants of 5 provenances survived. (See Table 3.2.4).

Table 3.2.4 : Survival rates of remaining provenances of Robinia pseudo-acacia

Origin	Provenance	Established Plants	Surviving Plants (July, 2001)
North America	Unidentified	30	9
Canada	Elizabethville	30	2
Canada	Elizabethville	30	1
U.S.A.	ON Weritgomery	30	14
U.S.A.	ML Mordcalm	30	1
China P.R.	Zhanggutai	30	4

Broadleaved afforestation trials in co-operation with the BFU¹

In 1999 and 2000, a total of 37 broadleaved species (and 8 coniferous species) were introduced from abroad and nursery and afforestation trials established at Zhangguttai of the Liaoning Sand Fixation Research Institute. The results are presented in Table 3.2.5.

Several species did not survive nursery production, due to low germination rates or other reasons. It has to be observed that one reason might be that propagation/cultivation techniques are not sufficiently soffisticated, and that it is too early to completely write off any of the species that did not make it through the propagation stage.

Several species showed high mortality after the first winter, which may indicate that they are not winter-hardy enough to resist the low temperatures in the region.

3. 3 Preliminar conclusions regarding broad-leaved species trials

On a preliminary basis the following species should be further considered: Fraxinus americana and Celtis occidentalis selected at Zhanggutai Forest Farm; and Morus alba and Rhus trilobata selected at Xinglongzhao Forest Farm.

From May 1999 to the beginning of 2002, the Region was affected by an exceptionnal and severe drought. During winter of 2000-2001, temperatures were extremely low, which made a large number of introduced tree species that had survived sofar, die. In general, indigenous species are showing a better survival than introduced species. However, this may be partially due to the fact that the nursery and planting requirements for the native species are better known than for the introduced speices.

Table 3.3.1 : Nursery and field survival of introduced broadleaved speices at Zhangguttai
(including 8 coniferous species)

1 Realised through Prof. Shen Xihuan of the Beijing Forestry University.