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Breeding and conservation of black poplar ( nigra) gene resources in

F. Toplu

With black poplar in native stands urkey is characterized by widely are hybrid poplars and 60 000 ha con- threatened in Turkey, action to varying climatic and topographic sist of various clones of black poplar. manage and conserve the genetic Tconditions which result in a Black poplar provides about 57 percent resources of this valuable broad diversity of forest ecosystems, of Turkey’s 3.5 million cubic metres of is showing promising results. species and within-species variation. annual poplar wood production. Poplar European black poplar (Populus nigra) wood industries – particularly furniture, has a wide distribution in Turkey and has packaging, particleboard, plywood and been cultivated by farmers on private matches – have developed very quickly lands for centuries. It makes consider- in recent years and mainly use the wood able contributions to both the rural and of hybrid poplars. On the other hand, the national economy. However, with more than 80 percent of black poplar urban expansion and mismanagement wood (1.75 million cubic metres) is used of natural resources in rural areas, it is as roundwood for rural construction and one of the most threatened species for the daily needs of rural people. in native stands in Turkey – as it is also in . Ferit Toplu is with the Poplar and Fast-Growing Turkey has approximately 130 000 ha Forest Research Institute, Yahyakaptan, of poplar plantations, of which 70 000 ha Black poplar plantation Izmit-Kocaeli, Turkey. around agricultural fields, , Central region F. T oplu F.

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Black poplar field clone trial, , Central Anatolia

In some parts of central, eastern and southeastern Turkey, black poplar is cul- tivated in field, roadside and riparian plantations using traditional methods. Where land is reserved for agriculture, row plantations can protect arable land and produce wood for local needs. In the F. T oplu main river basins, about 100 000 km of waterways are suitable for gallery plan- tations, i.e. one to three rows of poplars Resources Programme (EUFORGEN). also capable of vegetative regeneration. planted on both sides of the waterway Under these programmes, five previ- Its seeds are disseminated by wind and (Semizoglu, 1979); some gallery planta- ously unknown natural populations of water, have short viability and need spe- tion projects are under way supervised black poplar have been identified in the cific soil and humidity conditions for by the Ministry of Forestry. . germination. Regeneration is generally Poplars are also of ecological poor within long-established stands. importance as centres for biodiversity. BIOLOGY, ECOLOGY AND The most widely cultivated clones of A large number of threatened and DISTRIBUTION black poplar in Turkey are P. nigra var. common species are associated with The natural range of European black italica, used mostly in the western part or dependent on poplars, particularly poplar, Populus nigra, includes most of the country, and Populus usbekis­ in floodplain forests, which are among of Western Europe (with the exception tanica var. afghanica, which is more the most diverse ecosystems in Europe of Scandinavia, and Scotland), widespread. Both have characteristic (Rotach, 2003). Thus the monitoring and Ukraine, the Russian Federation, parts narrow, pyramidal crowns. conservation of the genetic resources of North and Minor, and of black poplar in riparian ecosystems northern Islamic Republic of Iran. Black SELECTION AND BREEDING is of major significance, not only for poplar usually forms local populations Black poplar is used in breeding pro- the natural control of flooding, but also by colonizing open areas on alluvial grammes in many parts of the world: because the river borders harbour great soils through seeds, cuttings or root 63 percent of the poplar used biodiversity. fragments. Its distribution extends from in forest plantations descend from black This article describes efforts made in isolated trees to large blocks of pure or poplar. To improve the quantity and qual- recent years in the breeding, conser- mixed stands. Individual trees may live ity of wood harvested from poplar planta- vation, management and utilization of up to 400 years. Almost 40 percent of tions in Turkey, classical breeding pro- black poplar genetic resources in Turkey. black poplars are grown in line planta- grammes with Populus deltoides, native This work has included the establish- tions along canals and stream banks and P. nigra and Populus × euramericana ment of clone banks and clonal trials in around irrigable fields. are in progress for commercial release of nurseries and fields and the identifica- Black poplar trees are dioecious, with the most productive hybrid clones. Use- tion of black poplar clones with high separate male and female individuals. ful traits of parents such as fast growth, growth performance and adaptability They grow fast and reach the reproduc- desired wood quality and resistance to to different ecological conditions. In tive stage at approximately ten years of frost can be combined in a hybrid, and addition, ex situ and in situ conservation age. In the early spring (early April in some clones are selected from intra- or programmes for black poplar have been Turkey), male and female trees produce interspecific crossings. in progress in Turkey under the frame- flowers clustered in pendulous catkins. Domestic black poplar provenances work of the European Forest Genetic Black poplar is wind pollinated and is are included in the breeding programme

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Natural distribution of black poplar Black (Populus nigra) Sea in Turkey

Melet Kelkit

Ankara Munzur Pülümür

Karasu

Mediterranean Sea

Locations of clone banks and field trials in Turkey Finally, gene introgression (i.e. move- Locality Region Clone banks and field trials ment of genes between genetically dis-

Harran Southeastern Anatolia Nursery clone trial tinct populations) from cultivated clones First selection clone trial and other poplar species is a potential Tunceli Eastern Anatolia First selection clone trial threat to the integrity of black poplar, Erzurum Eastern Anatolia Clone bank because only a few clones are widely Nursery clone trial First selection clone trial cultivated and these contribute mark- Ankara Central Anatolia Clone bank edly to the pollen and seed pools in Nursery clone trial native stands. This risk concerns not only First selection clone trial introduced hybrids, but also pure black Kutahya Inner Aegean Nursery clone trial First selection clone trial poplar varieties with wide distribution Second selection clone trial such as P. nigra var. italica. Izmit Clone bank Therefore, it has been necessary to take action to conserve and manage Turkey’s because of their adaptability to continen- THREATS TO GENETIC RESOURCES valuable black poplar heritage. Clone tal conditions. They are widely planted in Three main factors threaten the genetic banks in nurseries and clonal field tri- eastern European countries for domestic resources of European black poplar als have been established in a range of use and for soil protection and afforesta- (Lefèvre et al., 2001). First, human activ- climatic zones (see Table). Considerable tion in polluted industrial zones. Black ities alter riparian ecosystems through- progress has been made in the conserva- poplar is hybridized with P. deltoides and out the species’ distribution area. Native tion and identification of black poplar other introduced poplar species such as poplar stands are being displaced by clones with high growth performance Populus maximowiczii and Populus tri­ agriculture and floodplain areas are sub- and adaptability to different ecological chocarpa which provide adaptability to ject to urbanization. Regulation of floods conditions. various soil and climate conditions, root- has altered the regeneration capacity of ing ability, high resistance to bacterial the species and favoured the succession CONSERVATION OF BLACK canker caused by Xanthomonas populi of poplar stands by hardwood forests. POPLAR IN TURKEY and fair resistance to Marssonina brun­ Although regeneration may be success- In situ conservation nea and to poplar mosaic virus (Cagelli ful locally, some regions of Europe Conservation programmes in Turkey, and Lefèvre, 1995). have witnessed significant reductions undertaken within the framework of the Populus nigra × P. nigra hybrids and in native black poplar populations or European Forest Genetic Resources Pro- P. deltoides × P. nigra hybrids are being their complete disappearance. gramme (EUFORGEN), focus on in situ selected through nursery and field clone Second, the autochthonous black pop- conservation. trials in Turkey. Successful clones are lar resources have been overexploited The ultimate aim of in situ conservation registered nationally and internationally for the use of wood and wood products of a species is to maintain broad genetic by the International Poplar Commission and faster-growing hybrid poplars have diversity so that the species can retain (IPC). been planted to replace them. its potential to adapt to changes in the

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environment. When the objective is to conserve genetic diversity and maximize the adaptive potential of the species, dynamic conservation is preferable. This can be achieved through in situ conserva- tion of native stands, long-term breeding programmes or both. Conservation work has led to the con- tinual identification of new distribution areas, especially in Eastern Anatolia where five natural populations have been identified, in the basins of the Melet, Kelkit, Munzur, Karasu and Pülümür rivers (Toplu and Kucukosmanoglu, 2003) (see Map). However, areas suitable for in situ con- servation are limited because native pop- F. T oplu F. ulations of black poplar are threatened In situ gene conservation of black poplar, by urban expansion and poor manage- the experimental nurseries in Izmit, Zonguldak, western ment of rural resources. Therefore in situ Erzurum and Ankara (Toplu, 1996). conservation is often supplemented or Individual “passport data” (accession replaced by ex situ conservation, which identity number, species scientific name, is being given increased emphasis. institution of origin, sex, latitude, longi- tude and altitude of origin, geographic Ex situ conservation zone, means of conservation) have been Ex situ conservation of black poplar recorded at the Poplar and Fast-Growing in Turkey has been carried out by the Forest Trees Research Institute. A large Individual selected for ex situ conservation, Poplar and Fast-Growing Forest Trees part of these clones are native and some Kütahya, Research Institute in Izmit since 1962. are the result of controlled cross-pol- A countrywide conservation programme lination (P. nigra × P. nigra). During was started in 1990 to conserve black the selection of clones to be conserved, poplar genetic resources in ex situ col- emphasis has been placed on including lections. From 1990 to 1993, 310 black frost-resistant individuals. poplar individuals were selected in natu- ral relict populations or aged plantations CONCLUSION in different regions of Turkey. From Black poplars have considerable eco- this collection, 297 clones were trans- nomic and social importance in Turkey, ferred to stool beds at the experimental especially in rural areas. They also have nurseries in Izmit and Ankara. This col- an important role in poplar breeding lection was duplicated in the nursery at programmes. The loss of black poplar Erzurum using material of 221 selected area and genetic resources and related clones. In addition, 36 native clones degradation of land affects the welfare selected in previous years (1956 to 1967) of the Turkish people. If mismanagement and 32 clones obtained from controlled of the environment continues, conserva- cross- were included in the tion of genetic diversity can no longer be collection. left to nature. Therefore, the following These conservation activities continue. active steps must be taken to conserve, In 1995, material of 760 individuals, develop and utilize the valuable black again selected from natural relict popu- poplar heritage in Anatolia.

lations and aged plantations, was col- • Inventory activities on black poplar F. T oplu lected and established in stool beds at should be kept up continuously to

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maximize the genetic base of the spe- cies. • Black poplar individuals and stands within riparian ecosystems should be characterized and protected. Bibliography • Field surveys should identify addi- tional in situ distributions of black Cagelli, L. & Lefèvre, F. 1995. The poplar in coming years, and these conservation of Populus nigra and gene areas should be included in conserva- flow with cultivated poplars in Europe. tion programmes. Forest Genetics, 2: 135–144. • New areas of ex situ genetic resources Lefèvre, F., Barsoum, N., Heinze, B., Kajba, should be established. D., Rotach, P., de Vries, S.M.G. & Turok, • Importance should be given to the J. 2001. In situ conservation of Populus control, standardization and certifi- nigra. EUFORGEN Technical Bulletin. cation of black poplar reproductive Rome, , International Genetic material. Resources Institute (IPGRI). • Technical information on black pop- Rotach, P. 2003. Poplars and biodiversity. lar should be disseminated to poplar In Populus nigra Network, report of the growers through publications, meet- seventh meeting, 25–27 October 2001, ings and technical excursions. Osijek, Croatia. • New black poplar clones should be Semizoglu, M.A. 1979. Modern poplar created through research to increase development handbook. Izmit, Turkey, poplar wood production. u Poplar and Fast-Growing Forest Trees Research Institute. Toplu, F. 1996. Breeding and conservation of genetic resources of black poplar (Populus nigra L.) in Turkey. In I. Bach, ed. Environmental and social issues in poplar and willow cultivation. Proceedings, 20th session of the International Poplar Commission, Budapest, Hungary, 1–4 October 1996, Vol. II, p. 623. Budapest, Hungary, FAO. Toplu, F. & Kucukosmanoglu, F. 2003. Two natural distributions of Populus nigra L. discovered in Turkey. Journal of Poplar and Fast-Growing Forest Trees Research Institute, 29: 23–32. u

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