Genetic Resources and Crop Evolution 00: 1–0, 2001. 1 2001 Kluwer Academic Publishers. Printed in the Netherlands.

Conservation strategies and management guidelines for wild Prunusgenetic resources in Andalusia, Spain

*´Jose Luis Vivero, J. Esteban Hernandez-Bermejo and Josefa Prados Ligero*´ ´The Botanic Garden of Cordoba, Avda. de Linneo s /n, 14004 Cordoba, Spain; Author for correspondence

Received 24 March 2000; accepted in revised form 2 February 2001

Key words: Andalusia, Conservation guidelines, Genetic resources, Prunus, Spain

Abstract

Six species of the genus Prunus occur in Andalusia. Matters regarding their ecology, ethnobotanical aspects andconservation are discussed, as well as knowledge about the germplasm of those species with greater economicimportance and their degree of conservation, namely: P. avium, P. mahaleb and P. insititia. Various conservationmeasures are proposed for wild germplasm and for the germplasm of local varieties: a) conservation efforts shouldtarget the best populations, except in the case of P. avium and P. insititia, where every individual should beaddressed, including both wild and local cultivars; b) the Dehesa del Camarate (Sierra Nevada) is proposed as anarea for in situ germplasm conservation; c) the awareness of the importance of Prunus germplasm should beincreased among forest workers, environmental managers and the public; d) some silvicultural techniques areproposed, such as mixed Prunus patches, hedge treatment, Z-tree selection at the early stages and the protection ofroot suckers; e) improved, selected P. avium and P. mahaleb germplasm should be used at highly productive sitessince these two species can be cultivated as high value timber trees; f) some Prunus species can also provideprofitable NTFPs in the region. Details regarding different collection areas are covered. Finally, some topics arerecommended for scientific research. Three tables and a distribution map of Prunus species in Andalusia areincluded.

Introduction pathogens (Toval and Vega 1988). The genus Prunusis very important from an agricultural perspective,

The purpose of this paper is to draw attention to since it includes some very important fruit trees,Prunus germplasm in Andalusia, its conservation namely almond, apricot, peach, plum and cherry trees,status and to outline management guidelines, thus all of them cultivated in Andalusia. There are 12 wildproviding the basic information that is necessary for Prunus species in Europe (Webb 1968), 8 of which

´this germplasm’s protection and use. A practical goal occur on the Iberian Peninsula (Blanca and Dıaz de lais that selected sites be proposed for accessions and Guardia 1999). Wild Prunus, especially P. mahaleb,silvicultural practices that promote the management P. insititia and P. spinosa, are very valuable in theand use of Prunus species in the region. Very few improvement of rootstocks that are currently beinginventorial studies have been done on the wild Prunus developed. P. avium is also highly valued for itsspecies found in the Mediterranean Basin, in spite of wood. At present, there is a European Cooperativethe fact that such inventories are a prerequisite for Program for the Conservation and Exchange of Cropgene conservation strategies for tree species (Turok et Genetic Resources (ECP/GR) directly involved inal. 1998). High altitude adaptations and pest resist- Prunus germplasm conservation, and a Prunus Work-ance that were revealed in ecogeographical surveys of ing Group that was created specifically for this matter.wild relatives of fruit trees are suggestive, since the But it seems that the germplasm native to Spaincommercial varieties that are traditionally cultivated (Socias 1996) has not been a serious considerationat lower altitudes (, 600 m) are very sensitive to within these conservation frameworks.

ICPC - XPS 30494 (GRES) - product element 334956 - Wed Aug 22 11:04:02 2001

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Targeted species Species of minor economic importance

Andalusia, the southern part of the Iberian Peninsula, Prunus prostrata Labillis a cross road between two continents and threebiogeographical regions. Moreover, it is home to a Its name comes from its prostrate growth habit, sincewide variety of regional climates and several moun- it adapts to the microtopography of the rocks where ittain ranges with high peaks (Sierra Nevada, 3478 m). grows. It is distributed throughout the MediterraneanThese features have created an enormous diversity in Basin. In Spain, it only occurs in the oro-mediterra-the region’s flora, with up to 4000 taxa, more than 450 nean thermotype found in the eastern provinces (seeof which are classified as restricted regional endemics Table 2 and Figure 1). In Andalusia, it is widespread

´(Hernandez-Bermejo and Clemente 1994; Rivas-Mar- all along the Baetic Range, reaching all the way to´ ´tınez et al. 1997). This same species diversity in Cadiz in the south, with no threats to its survival

Andalusia can be observed in the genus Prunus, with foreseen in coming years. No uses for this species arethe presence of six out of the eight wild species, reported in literature, nor known from the field. The

´namely: P. avium, P. insititia, P. mahaleb, P. pros- herbarium at the Botanic Garden of Cordoba housestrata, P. ramburii and P. spinosa. The other two more than 50 specimens from the region. Recently, aspecies, P. lusitanica L. and P. padus, L. are not different and more erect form (P. prostrata f. erecta

´currently present in the region, but it is quite probable Molero) was found in Sierra del Jobo, Malaga (Lorathat they were in the past. They disappeared mainly and Vivero 1998).

´due to the climate constraints (Vivero and Hernandez-Bermejo 1997). P. lusitanica was sighted in Sierra de Prunus spinosa L.

´Algeciras, province of Cadiz and P. padus in SierraNevada, province of Granada. This species grows in nearly all the European coun-

Of the six species found in Andalusia, this paper tries, the Caucasus, northwestern Africa and south-focuses on the species which have a distinct economic western Asia, all the way to Iran. It prefers calcareousor social value: P. avium, P. insititia and P. mahaleb. soils in rocky places and on ledges, at either high orThough the other three are of minor importance low elevations. It is more abundant in the north andeconomically (P. prostrata, P. ramburii and P. spi- center of Spain, and is only rarely found in the south.nosa), their main features are outlined and included in It occurs in all of the provinces of Andalusia, but onlythe general conservation guidelines. Their distribution in very few places. Watkins (1976) considers it one ofin the eight provinces of Andalusia is shown in Table the parental species of P. domestica. Another hypo-1 and Figure 1. P. avium is a special case since it thesis indicates that it may be the parental species ofgrows wild and cultivated at the same time in many P. insititia, which, later on, evolved towards P. domes-places and it is difficult to distinguish natural forms tica. The latter of the two would thus conserve thefrom cultivated ones. Since it is a traditional crop in characteristics of its primitive parental species, P.the region, its many semi-domesticated and wild spinosa. Its fruits are used in the north of Spain toforms make Andalusia an important center for germ- produce a liquor called ‘Patxaran’, which is in greatplasm diversity on the Iberian Peninsula. demand in the Spanish market (Ruiz 1989). It is not

Table 1. Presence and population sizes of Prunus species in the eight provinces of Andalusia.

´ ´ ´ ´ ´Almerıa Granada Malaga Jaen Cordoba Sevilla Cadiz Huelva

P. avium ? XX x XX x XP. insititia x XX X XX XX x x xP. mahaleb x XX XXX XXX X XXXP. prostrata X X XX XX XP. ramburii XXX XXXP. spinosa ? X XX XX x x X

Legend: (XXX) big population; (XX) abundant; (X) rare; (x) one or two localities.

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Figure 1. Distribution of Prunus species in Andalusia.

threatened regionally, nor in a larger context. Its uses will benefit from the conservation plans that will beand ethnobotanical applications in the region are very applied to the species of major economic importance.rare and localized, therefore we do not consider it It potentially could be quite valuable as a rootstock fornecessary to immediately develop a specific conserva- commercial Prunus species in genetic improvementtion and management plan for its germplasm, since it programs. It seems that there are many genotypes

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Table 2. Conservation and ethnobotanical features of the germplasm of Prunus species in Andalusia.

P. avium P. insititia P. mahaleb P. prostrata P. ramburii P. spinosa1IUCN category VU VU LRcd nt VU nt

2Degree of Endemncity WD WD WD MB EA WD3Biogeographical singularity Intermediate Low Intermediate Low High Low

4Ethnobotanical importance High Intermediate Intermediate Low Low IntermediateImportance of wild High Intermediate High Low Low Inter

5germplasm6Likelihood of sustainability Low Intermediate High None Intermediate Intermediate

7Regional occupancy 580 250 1700 1350 1200 7208Neglected crops Important Important Little None None Little

Susceptibility to genetic Low Low Low Low High Loweffects of natural regeneration

9systems10Minimum bioclimatic level Meso Meso Meso Meso Supra Termo10Maximum bioclimatic level Supra Supra Oro Oro Oro Supra

11Population size , 1000 , 5000 , 10000 . 10000 , 10000 , 500012Habitat specific Yes No No Yes Yes No

13Flagship species Yes No No No No Medium14Wood High Low Intermediate Low Low Low

15Relative endemicity Low Low Low Intermediate High LowThreats Fire, tree Fire Fire None Fire, local use Fire

felling and and biologicalnatural factorsdecline

1 ´After Vivero and Hernandez-Bermejo (1997).2 EA: Endemism restricted to Andalusia. MB: Restricted to Mediterranean Basin. WD: Widely distributed.3 Ecological and geographical characteristics of the species that make their gene pool somewhat different from other populations within thesame distribution range (i.e. adaptation to higher elevations or drier climate, border area of a broader range, relic species, different subspeciesor varieties).4 See Table 1.5 Present and potential future importance of their germplasm for use in genetic improvement programs, for rootstock properties, diseasetolerance, wood quality, characteristics of the fruit, etc.6 After Newton (1998). Depending on which part of the tree and with what intensity it will be used, the sustainability will be higher or lower.7 2 2The total occupancy area (km ) is estimated by the index: UTM 3 100 3 CA, where UTM is the number of grid squares (10 3 10 km ) andCA is the maximum percentage of each UTM grid square physically occupied by the species.8 This aspect refers to the agricultural or economical importance of the species in the past.9 The actual susceptibility will vary per species, biology, population size, and how extensively the silvicultural system is applied (Joyce et al.1999). And the genetic effects that affect the genetic variability can be: local extirpation (the loss of a local population due to regenerationfailure), inbreeding depression, genetic drift and high grading (leaving phenotypically undesirable trees for seed production).10 ´After Rivas-Martınez et al. (1997). Thermomediterranean (0–700 m); Mesomediterranean (700–1300 m); Supramediterranean (1300–1800m); Oromediterranean (1800–2800 m).11 ´Estimated number (after Hernandez-Bermejo et al. (1998)).12 After Rabinowitz (1981).13 Species that are well known by the public and are well considered. The possibility of obtainining program funding is higher than for otherspecies.14 High: Highly valued wood with several applications. Intermediate: Wood used to make small objects, or in specific activities. Low: Woodwith no or just a few restricted applications at present.15 After (Freitag and Van Jaarsveld 1997).

resistant to PPV in wild P. spinosa populations that with a very restricted range at high altitudes (1200–could be used as dwarfing rootstocks or intrageneric 2000 m) in the three Baetic mountain ranges: Sierra

´stocks for plums and apricots (Ogasanovic 1996). Nevada, Sierra de Baza-Filabres and Sierra de Gador.Lower altitudes represent a barrier to its extension. In

Prunus ramburii Boiss. this ancient, widespread genus, it is quite uncommonto find an endemism with such a restricted range. It is

This is the only Prunus species endemic to Spain, a neoendemism whose origins date back to the

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Quaternary, with P. spinosa as ancestor (Vivero and Andalusia, it occurs in scattered populations on sever-´Hernandez-Bermejo 1998). Due to its reduced range, al mountains at elevations of 1300 to 1800 m, in

its endemicity and several threats it faces, such as fire, habitats that favor this species because the lack oftourism and low seed production, it is rated Vulner- water is mitigated during the summer months. Theable and has appeared in the recently published world climate nowadays, with its long dry summers, greatlylist of threatened trees (Oldfield et al. 1998). There- restricts its range in the region and may even affect itsfore, a program has been outlined to conserve its survival in the next decades. In Sierra Nevada, it is notpopulations in Andalusia, as is explained in this paper. clear whether the populations are wild or naturalized.

´Some of its biological features should be highlighted, In Malaga, all the populations seem to come fromsuch as its pronounced demand for light exposure and trees escaped from cultivation, either recently or someits very low fructification levels (Vivero and centuries ago, since the habitats where they occur are

´Hernandez-Bermejo 1998). Nonetheless, it is com- not those most suitable to them. Prunus avium is rated´monly propagated by vegetative means (root prop- vulnerable in this region (Vivero and Hernandez-Ber-

agules). It is abundant within its range, forming mejo 1997). In response to frequent summer droughts,characteristic shrub communities, with some popula- P. avium grows in the wet ravines of the Andalusiantions that are protected in Natural Areas. There is no mountain ranges, in circle formations produced byliterature regarding its uses, but we report that a kind saplings which grow from the main tree’s roots. Itof ‘Patxaran’ liquor is made with its fruits in the also appears at the bottom of cliffs, as a result of seedSierra Nevada National Park. dispersal by birds and mammals. It prefers cool, deep

soils, since it has a taproot capable of growing veryPrunus x fruticans Weihe deep. Though it is indifferent to edaphic conditions, it

does grow better in acidic soils.This hybrid species, described 100 years ago, has As a crop, it has traditionally been associated withrarely been sighted on the Iberian Peninsula. It has marginal orchards in mountain areas in Spain. Inrecently been recorded in three places: Granada, some countries, such as Canada, France and Belgium,Cuenca and Girona (see Figure 1). Its origin is not yet breeding and genetic improvement programs for com-clear. It is either a natural hybrid of P. spinosa and P. mercial varieties and rootstocks were started severalinsititia, or of P. insititia and P. domestica, the latter decades ago. At present, there are wild P. aviumoption being more probable than the first. germplasm evaluation programs in UK, Belgium, in

Navarra (Puertas and Traver 1997) and Galicia (Vega1996), Spain, among others. Most of them focus on

Species of major economic importance improving timber quality.

Prunus avium L. Prunus insititia L.

Its natural range includes Europe, western Asia and This species occurs in Europe, the Middle East andnorthern Africa, but it has been introduced or natu- northern Africa. On the Iberian Peninsula, it occurs in

´ralized in many countries. During Quaternary glacia- nearly all of the provinces (Blanca and Dıaz de lations, as can be inferred from its present distribution Guardia 1999). It prefers hedges and forest borders inand from paleobotanic and paleoenvironmental data, meso- and supra-mediterranean thermotypes, normal-the Iberian Peninsula probably was a refugium for P. ly with scattered or very few individuals per stand. Itavium coming from central Europe, as was the case is found in mountain areas in all of the eight provinces

`for Quercus spp. (Dumolin-Lapegue et al. 1997) and of Andalusia, at elevations no higher than 1600 m (seeFagus spp. (Demesure et al. 1996). This is why it is Table 2), though five of the provinces have only oneconsidered a relict species with declining populations. population each. Some of these individuals may actu-

´There are scattered populations in a geographical strip ally be naturalized P. domestica (in Malaga or the´stretching from Sierra Nevada to peninsular Italy, Sierras Subbeticas, Cordoba). It always occurs in wet

which occur between its core range in central Europe habitats: in ravines, along steep pathways and slopes,and the southern limits of its range in the Atlas in hedges, and in riparian or oak forest borders. It isMountains of Morocco. On the Iberian Peninsula, it is indifferent to edaphic conditions (Ruiz de la Torrecommon in the north, becoming rarer in the south. In and Ceballos 1971).

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Prunus mahaleb L. fruits. Fruit: wild trees yield between 4 and 16 kg offruit, that can be eaten fresh or in jams. The fruit is

This species is widely distributed throughout the also an important food source for birds, mammals andMediterranean Basin, reaching all the way to Norway insects living in the forest. Gardening: it is used for itsin the north and to Iraq in the east. It is quite abundant brilliant autumn foliage. Timber: a heavy hardwoodon the Iberian Peninsula, and its presence has been with a dark reddish grain pattern that is highly valuedrecorded practically over the entire peninsula (Blanca for carvings and furniture making. After walnut, it is

´and Dıaz de la Guardia 1999). Its ecology on the the hardwood that is second most in demand in the´Iberian Peninsula is quite varied, with individuals European market (Orıa de Rueda 1991). Medicinal

found growing on high rocky mountains as well as at Uses: see Table 3. The fruit peduncles boiled in watersea level, and in cool, wet places or on exposed, sunny are used as a diuretic, and for bladder and liverslopes. In Andalusia, it occurs in the Baetic Range, infections (Sierra Nevada, Sierra de Baza and

´where it normally grows in scattered groups through- Cordoba). Other Uses: its flowers are popular without the forest. It is widespread on mountains, in deep bees, which produce a strongly scented honey fromvalleys, in canyons, on cliff walls and in gorges. It the nectar.occurs at altitudes between 1050 and 1900 m, whichis higher than the elevations where these plants are Prunus insititianormally found on the rest of the Iberian Peninsula(Vivero et al. ). It prefers sunny places, but it can be Agriculture: its main use is as a rootstock for stoneseen growing well in shaded fissures and holes, with fruit trees, mainly plums and apricots. Because P.no light; or in very wet, dark ravines. Based on these insititia belongs to the Prunus subgenus that shares afacts, we considered this a very shade tolerant species, common gene pool with other subgenera, it is able tothough it does prefers warmer, well-lit places. It act successfully as a rootstock. Fruit: they can beclearly prefers calcareous soils, but there are two eaten either fresh or dried, being excellent laxatives.rather interesting populations (Sierra de Horna- Timber: reddish-pink, with a fine, compact grain,

´ ´chuelos, Cordoba and Sierra Morena, Jaen) in silice- perfectly suited for polishing to a rich luster. Medici-ous soils. Its reproduction biology has been studied nal Uses: see Table 3. Its most extended use is as a

´ ´extensively (Guitian 1993; Guitian et al. 1993; Her- laxative and as an ingredient in common cold re-rera and Jordano 1981). medies. The leaves and seeds also contain a glucoside,

amygdalin, that is used in the pharmaceutical industryas a substitute for bitter almond essential oil (Ruiz de

Economic and ethnobotanic interest la Torre and Ceballos 1971).

Prunus avium Prunus mahaleb

P. avium is one of the most useful trees of Europe. In Agriculture: at present, this species is one of the mostmany cases, it generates a higher profit than widely used rootstocks in the sweet cherry orchards ofEucalyptus, Pinus and exotic Abies species, as a Spain, especially in Aragon and Catalonia, where it isresult of its multiple by-products. One of the main well suited to the dry and calcareous soils found thereconstraints for its use in plantings is its initial delay in (Herraiz 1992; Gella 1990). These rootstocks permitfructification (8–10 years), though it does grow as a the cultivation of commercial varieties of P. avium,pioneer species during the first stage. At present, its which is more adapted to wet, acidic soils. The Moorsimpact on the Iberian ecosystems is minimal, since it used it as rootstock when they introduced its cultiva-only occurs at low densities. Given its multiple uses tion in the Iberian Peninsula. Fruit: though the fruit isand scarcity, it has been used extensively for several not currently consumed in Andalusia, it is used todecades in reforestation and landscape management elaborate traditional desserts in Iran and Iraq. Garden-plans undertaken in central Europe, especially in ing: several special garden cultivars exist which areGermany and France. mainly planted in central European countries. It is

Agriculture: wild specimens are used as rootstocks also used to form hedges since it sprouts readily afterin some areas (Sierra de Aracena, Huelva). Bever- pruning. Timber: whitish-pink, with a pleasant scentages: homemade spirits are made from the macerated due to the essential oil (coumarin) it contains. It has a

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Table 3. Medicinal and other uses of the major Prunus species

Prunus Prunus Prunus Prunus Prunus Prunusavium insititia mahaleb ramburii spinosa prostrata

Antihistamine d

Hemorrhoid treatment d

Diuretic d d d

Bladder infection relief d

Rheumatism treatment d

Antispasmodic drugs d

Laxative d

Astringent d d

Digestive aid d d d

Sedative d

Cold remedies d

Rootstock d d d d

Alcoholic beverages d d d d

Fresh fruit d d

Gardening d d d

Timber d d d d

Honey d d d

very homogeneous grain and is readily polished. It is most of the institutions have tended to preserve theused to make cigar boxes, pipes and walking sticks. germplasm of commercial varieties in their collec-Theophrastus (4th century B.C.) mentions that its tions, rather than that of wild Prunus species. Addi-wood was used for carriage axles and for plows. tionally, some old cultivars have been replaced by theMedicinal Uses: see Table 3. It is a digestive aid and a introduction of modern cultivars. This situation hasdiuretic. caused the extinction of many locally developed and

climatically well-adapted old cultivars (Gass et al.1996).

Current situation of germplasm evaluation in Andalusia is still home to many local old cultivarsAndalusia of P. avium, since little work has been done in the

region to commercially improve this crop in recentAlthough the flora of Andalusia has been relatively decades. Therefore, a project should be undertaken towell researched, its tree germplasm has not been collect, evaluate and conserve these varieties, whichsurveyed to the same extent, with no reference materi- may result in very interesting material for currentals on the topic. Variation patterns within species, genetic improvement projects. Due to the methodo-subspecies or varieties are entirely undocumented in logical approach, it was outside the scope of thismany cases, as for Prunus, both for wild populations paper to embrace the local landraces of Prunus fruitand for local cultivars. Little has been done with trees and their evaluation. Vigorous wild P. aviumregard to the collection of wild germplasm, and only individuals with good tree structure (a straight trunksome notes can be found about germplasm accessions with light branching) can be used for clonal trials inin the region. For example, there are no accessions of timber-oriented cherry breeding programs, as haswild P. avium from Andalusia at the Experimental been done in East Malling, UK and in Gembloux,Research Center in Aula Dei, Zaragoza; and at the Belgium. Or well adapted P. spinosa and P. mahaleb

´Aragon Regional Government;s Department of trees can be used as a source of resistance andFruticulture, there are only several wild germplasm tolerance to biotic and abiotic stress. Some areas thataccessions for P. ramburii. P. mahaleb, in spite of must be surveyed and evaluated are proposed asbeing a valuable genitor for rootstock breeding pro- Provenance Areas in this paper, since they are pri-grams and for seedling plantations, is barely present marily where these local varieties occur. In otherin the state-run genebanks of Europe, and almost cases, Selected Seed Stands would be advisable in thenon-existent in Spanish genebanks (Socias 1996). Natural Parks (NP) and the Regional Natural AreasSome work has recently been done with this species in (RNA) in order to develop specific programs toTurkey and Yugoslavia (Gass et al. 1996). Moreover, conserve this wild germplasm. See Figure 2 for a map

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Figure 2. Protected natural areas in Andalusia.

with the regional network of protected natural areas in measures in the hands-on conservation efforts, thoughAndalusia. we believe that whenever possible, the former should

be higher priority than the latter.Guideline 1.A.: Conservation and promotion ef-

General guidelines for Prunus conservation forts should focus on ecologically optimal sites, natu-efforts ral niches or special habitats, although all P. avium,

P. insititia and P. x fruticans individuals should beGeneral guidelines for a useful, cost-effective con- conserved whether they are located in ecologicallyservation program and specific silvicultural practices optimal sites or not.for managing the region’s Prunus germplasm are Concentrating efforts on ecologically optimal sitesoutlined in this section. These guidelines and sub- will lead to less intensive silvicultural interventionssequent conservation efforts are based in large part on and will thus allow us to focus our efforts on thethe excellent paper on noble hardwood species issued so-called ‘core populations’. In marginal or borderby Rotach (1999), with the necessary modifications areas where these species are rare or in situationsrequired to adapt his guidelines to the Mediterranean where they are severely threatened, other conserva-Region and to the specific characteristics of the tion measures should be undertaken regardless of sitePrunus species in Andalusia. As is the case with conditions. P. avium shows a border area pattern inseveral of the species studied, this adaptation is espe- the region, since it is quite far from its optimalcially important in less than optimal areas on the ecological and climatic niche. As mentioned before,northern and southern borders of the species’ dis- most of the habitats where it occurs are relict andtribution area. Some silvicultural practices and con- highly sensitive to degradation and destruction. For P.servation efforts are proposed as well, in order to x fruticans, this is even more evident, since it onlyincrease the numbers of trees, to enhance public occurs in one or two places (though its taxonomicawareness of these trees, to improve the quality of the position inside the group is not yet clear). Otherwood and its market profitability and to reduce its possible efforts could be focused on limiting in situcompetition with other species. For a summary of the measures to populations of more than 20 individuals,features of these Prunus species, see Table 2. For a as proposed in Turok et al. (1998). For P. avium andbetter analysis, we will combine in situ and ex situ P. insititia, concentrating conservation efforts on

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stands with more than 20 individuals seems reason- omic potential for timber and non-timber products,able; while for P. mahaleb and P. spinosa, the popula- this area should be selected for a pilot program on treetions should have more than 50 individuals. A popula- germplasm conservation and utilization. It is a keytion is defined as at least 20 individual trees, all place for linking seed conservation, in situ manage-distanced more than 50 m apart and distributed over ment of genetic diversity conservation and the sus-an area not exceeding 10 hectares (adapted from tainable use of timber and other products and services,Demesure (1998)). such as tannins, mushrooms, wood, coppice, pulp,

Guideline 1.B.: Some Prunus species should be soft wood, game preserves and grazing areas forfavored in special stand structures or habitats that cattle. This pilot program is to be controlled by theare particularly advantageous Such special habitats National Park authorities. This area is a real hotspotshould be managed primarily for the endangered for rare and threatened trees in Andalusia, and twominor or rare species. other Prunus species also occur there: P. insititia in

The following special habitats are interesting for low numbers and P. ramburii at higher altitudes.less competitive Prunus species, i.e. ones which The stands with the best and biggest populations ofrequire more sun exposure, are slower growing and P. mahaleb are in the Sierra de Grazalema RNA

´are smaller in stature, such as P. insititia, P. mahaleb, (Sierra del Endrinal and Pinar del Torreon), in theP. ramburii and P. x fruticans: a) Forest borders Sierra de Cazorla, Segura and lasVillas RNA (Madera

´Special treatment of the forest border is necessary in valley and the Hernan Perea fields), the oak forest in´order to promote these species. Patch-size plantings is the Sierra de las Nieves RNA and the Sierra Magina

the favored solution since competition with other RNA (the north face of Cerro Campanario). Althoughshrubs will be severe in the stand-establishment it grows very well in shady locations, it prefersphase. b) Hedges or small forest patches dispersed sunnier exposures and hence it is a potentially goodover agricultural land. It is well known that these candidate for border silvicultural practices. There areforest patches are not only important landscape ele- considerable populations of P. ramburii in the threements, but are also valuable as retreats for plants and main mountain ranges where it occurs, since this is itsanimals, as wind barriers and much more. optimal habitat. The best stands are in Sierra de

´Gador, a rather important natural area with outstand-Conservation efforts ing plant endemisms that is not under any legal

protection, in the Sierra Nevada NP (Trevenque,As mentioned above, P. avium is a relict species with Puerto de la Ragua, Dehesa del Camarate and Veredadeclining populations in the region, therefore the de la Estrella) and in the Sierra de Baza RNA (atprotection of all its populations and individuals should higher altitudes). Special attention should be paid tobe strictly enforced, also including naturalized local the species’ border areas, since this is where it adaptscultivars and old abandoned varieties. Nonetheless, to a lower habitat, namely Sierra de Filabres, Sierra

´we cannot forget that it also is a species with commer- Mecina and Sierra de Lujar.cial value (the price and demand for its timber con- Most P. insititia individuals occur in isolatedtinue to rise) and some silvicultural guidelines for its groups scattered over the mountain ranges, with some

´utilization will be drawn up as well. The best stand is small stands in the Sierras Subbeticas RNA, the Sierraon the northern slopes of the Sierra Nevada National Nevada NP (Vereda de la Estrella, Dehesa del Cama-Park (Dehesa del Camarate) in a mixed old broadleaf rate, Maitena valley), the Sierra de Cazorla, Seguraforest with Quercus pyrenaica Wild., Sorbus aria (L.) and las Villas RNA (Madera valley) and the Sierra deCrantz, Sorbus torminalis (L.) Crantz, Salix caprea las Nieves RNA (Genal valley). This species willL., Betula pendula Roth subsp. fontqueri (Rothm.) G. benefit most of all from silvicultural practices alongMoreno et Velasco, Acer opalus Mill. subsp. the forest boundaries and hedges, since it is not verygranatensis (Boiss.) Font Quer et Rothm. and Malus competitive and it is seriously threatened by introgres-sylvestris (L.) Mill. This forest is a private property sion and genetic drift. Finally, since P. spinosa and P.even though it is located within the National Park, prostrata are widely distributed throughout the moun-therefore it could follow a timber management pro- tain ranges of Andalusia with high population figures,gram. Considering its extention, its excellent state of no special conservation measures are proposed in thisconservation, its significant population figures for area. As for P. x fruticans, the only place where it isseveral interesting, threatened species and its econ- known that it grows in the region should be better

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surveyed and its population totally protected. Some ex and as approved seed or seedling suppliers for othersitu measures are recommended below, such as col- natural areas or commercial gardening enterprises.lecting and setting up a core collection for cultivation. This last idea, already mentioned in Guideline 1,

All the aforementioned stands, due to the number would not only increase the awareness of Andalusianof trees, can all be considered Selected Seed Stands plant germplasm, but would also produce economicfor each species and hence properly managed to benefits. A better knowledge of the genus Prunus inobtain high quality, selected, certified seeds for sever- Andalusia would lead to more intensive use andal purposes. All these areas will thus have an addition- enhanced consideration of its germplasm, either inal economic value. revegetation programs, slope fixing or in appro-

Guideline 2: For the successful conservation and priately weighing its importance in Environmentalpromotion of Prunus species, public perception of Impact Assessments.most of these species needs to be improved, especially Guideline 3: For species that are threatened bythe least known species. People working in the field introgression from domesticated germplasm (namely,need to be better trained and better motivated. P. avium and P. insititia), natural regeneration needs

As is logical, perception or awareness have a direct to be accompanied by plantings. Germplasm shouldcorrelation with knowledge, information and motiva- be highly diverse and contain a large proportion oftion. Consequently, the promotion of Prunus species wild genotypes from each respective origin / source.will neither be efficient nor successful unless the For certain species, natural regeneration may not bepersonnel working in the field are properly trained and sufficient for gene conservation. P. avium and P.committed. Fortunately, in the Andalusian network of insititia may, owing to their occurring at low den-Natural Areas and National Parks, most of the field sities, primarily cross-pollinate with domesticatedpersonnel know and easily recognize these Prunus individuals (commercial or local cultivars) outside thespecies and know where they are located. Nonethe- forest, and hence, it is doubtful whether P. insititialess, most of the personnel are not aware of the and P. avium populations in Andalusia can be consid-species’ economic and ecological importance as ge- ered as having any pure wild germplasm. For genenetic resources. This same awareness principle must conservation, these species need to be enriched withbe applied to government managers and park visitors. genetically diverse material which contains a highAll of these Prunus species are frequently found in proportion of undomesticated genotypes. Therefore, asmall populations in the natural sites within the re- reasonable solution for the above-mentioned speciesgion. Their populations could thus be increased con- is the establishment of seed orchards which containsiderably by training and supervising field staff to natural wild genotypes and produce genetically di-undertake early interventions in young stands. verse material. The conservation of these Prunus

species may require more effort and financial backing.Conservation efforts Since P. avium can generate high revenues from the

market price for its timber, these efforts may beFirstly, several workshops for foresters and forest worthwhile for the regional government and for somekeepers should be organized in the Natural Areas timber companies.where these species occur in order to increase theirknowledge and appreciation of these Prunus species Conservation efforts(as well as several other threatened, broadleavedspecies) and their ecological and economic impor- The establishment of a Special Seed and Seedlingtance in the region. A network of regional decision- Orchard with the aim of conserving and enhancingmakers, forest keepers and researchers could then be genetic variation in the wild germplasm of P. aviumset up in order to bring information about Prunus and P. insititia could be carried out by one research

´species up-to-date and to undertake conservation and institution, such as the Botanic Garden of Cordoba, inmanagement activities with their germplasm. Second- order that all the efforts, research and material bely, permanent expositions or in situ collections should centralized in a single place, thus enhancing thebe established in the Natural Areas where they occur interbreeding and the increase of genetic variation.in order to raise awareness among visitors. These Some preliminary research should be carried out incollections would fulfill a triple role: as tourist attrac- order to better determine which stands or individualstion for the area, the promotion of species awareness, have real wild germplasm (by using molecular

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markers or historical and geographical data). There prostrata and P. ramburii) easily lose out to thewill be many cases that create doubt, such as in- competition during their first 10–15 years. Earlydividuals growing in abandoned farm plots, in areas intervention therefore is essential for their survivalclose to a road, or in semi-urban areas, etc. Moreover, and conversion into future stands. At least one inter-special tree germplasm should also be included in this vention during the thicket stage is necessary to reg-seed orchard, such as the germplasm from P. mahaleb ulate the mixture and to favor all the forest Prunusfound growing in acid soil (Sierra Morena, Collado de species. Because of financial constraints, early inter-

´ ´los Jardines in Jaen and Conquista in Cordoba) or ventions need to be kept to a minimum and restrictedfrom old growth individuals (P. avium in Sierra de mainly to stands with high proportions of Prunus

´Aracena and P. mahaleb in Sierra Magina). Here are species. If Prunus individuals are selected as a topsome examples of naturalized or semi-domesticated priority, their chance of survival can be increasedgermplasm with no clear wild origin: P. insititia /P. considerably with little investment. For Prunus

´domestica in Sierra Bermeja and Sierras Subbeticas; species still occurring in moderately large populationsP. x fruticans and its relationships with the former (P. ramburii, P. prostrata and P. spinosa), efforts andtaxa and wild P. avium in Sierra Nevada, Sierra de financial resources should be invested primarily in

´Aracena and Sierra Magina. In order to avoid future supporting natural regeneration and early interven-introgression from non-native germplasm, the genetic tions. The promotion of some species depends pri-material from reforestation programs should be care- marily on vegetative propagation. The species P.fully checked and, whenever possible, come from avium and P. insititia frequently produce root suckers.certified Andalusian material. Special care should be Consequently, the promotion of Prunus species istaken both in the establishment of new orchards of P. especially promising in stands where a certain numberavium and P. domestica in the ranges where their wild of mature individuals occur. Root suckers can developrelatives occur, and with the possible introduction of at a distance of up to 25 m from the main trunk, soP. spinosa in Sierra Nevada for the elaboration of the immature individuals should not be cut, but rather left

´liquor ‘Patxaran de la Sierra’, since it produces larger, as standards until they reach maturity. In addition,more abundant fruit than P. ramburii. protection against grazing is necessary in most cases

Guideline 4. 1.: Silvicultural techniques to enhance since Prunus seedlings are especially vulnerable.Prunus populations in Andalusian forests. In Pinus orQuercus dominated sites, Prunus species should be Conservation effortsplanted in mixed patches ( groups of trees) rather thanas single trees. Since the conservation and enhancement of broadleaf

The growth rates for these species differ considera- species in Mediterranean forests should be a commonbly from those of pines and oaks, which are the goal in all the silvicultural practices undertaken eitherdominant Mediterranean tree species, and the com- for conservation or commercial purposes, these threepetitive ability for many of the Prunus species in practices must be performed in many forests in An-question is generally rather weak (with the exception dalusia, especially in the mixed forests and in thoseof P. ramburii and P. avium, which are pioneer that are under protection. These practices should bespecies). In groups of trees, these growth differences added to the regional Natural Areas’ forest manage-are less important since competition is restricted to the ment plans and their use should be promoted amongcontact zone between the species. Therefore, group the wood and forestry industries (either by legalmixtures are recommended since they are more stable, means or by state grants).silviculturally less intensive and thus more efficient Guideline 5: If a high silvicultural intensity can bethan tree-by-tree mixtures. guaranteed, P. avium and P. mahaleb /may also be

Guideline 4. 2.: In young stands with a high pro- promoted on highly productive sites. Growth andportion of Prunus species, initial interventions should productivity would be optimal on such sites and thebe aimed at favoring them primarily. At least one return on investments would be high for both species.intervention is necessary at the thicket or pole stage, For these plantations, only improved material withusing early plus tree (Z-tree) selections, in order to the best phenotypic quality should be used.conserve and favor existing Prunus species. Today, biological diversity is as equally important

The first 10 years are decisive for the survival of an objective as production. Consequently, all minormost Prunus species, since all of them (except P. Prunus species should be favored, even if the mix-

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tures are not ideal from a silvicultural perspective. lished. The logging of its timber should be strictlyThe economic potential of some Prunus species is monitored and controlled in the entire region, espe-very high. We believe that the prospects for the future cially in those areas with higher growth densitiesare even better, since certification would increase the (Sierra Nevada and Sierra de Aracena).demand for locally, ecologically and sustainably pro- The same type of collecting, evaluating and breed-duced wood and non-wood products. P. avium and P. ing programs should be applied to both the cultivarsmahaleb would both profit considerably from certified and naturalized varieties of P. avium and P. insititia.sustainable production of their useful and highly The setting up of a collection of P. avium for the

´valued timber. These species are more valuable than cultivation of local cultivars in the Sierra Maginathe dominant species (Pinus or Quercus), in spite of RNA and the Sierra de Aracena and Picos de Arochethe fact that their production volume is lower. P. RNA will undoubtedly be useful in order to avoid theavium, P. insititia, P. ramburii and P. spinosa would imminent loss of old varieties, which are alreadybenefit from the certification of some products other disappearing, as they are rapidly being replaced bythan wood, the so-called Non-Timber Forest Products, modern, more productive varieties. Local cultivars ofas explained below in detail. Wood quality primarily the P. domestica-P. insititia complex should be col-depends on stem form and the branching habit, and lected in the Sierra Nevada National Park and the

´these traits are often unsatisfactory for these Prunus Sierra Magina RNA, where they were locally used asspecies because they have been suppressed for too rootstocks and as minor fruit trees. Some of them stilllong. For example, production values for P. avium are do occur, scattered over old, abandoned plots on theseoften insufficient due to its frequent forking and mountains ranges. P. mahaleb has the potential tosinuous stem forms. Improving these traits by breed- produce quality wood (for musical instruments, pipesing would thus considerably enhance the value of its and small carved objects), so selected seed standstimber. Genetic improvement and seed production are could be set up in the Sierra de Grazalema RNA, the

´efficiently achieved in seed orchards that have select- Sierra Magina RNA and in the Sierras de Cazorla,ed, tested clones. Considering the difficulties that Segura and las Villas RNA.exist in the collection of a large number of seeds from For P. ramburii, its most important potential usessome Prunus species, orchard seeds may even be are as a slope retainer and in reforestation schemes.more diverse since the genes of more trees may be Since it is a species that is well adapted to therepresented in the offspring. Mediterranean climate and soil, and since it produces

Finally, Non-Timber Forest Products (NTFP) are an extensive root system, it is perfectly suitable forbecoming more and more a source of high income for plantings designed to prevent erosion caused by rain-well managed forests. So far, their importance and fall on mountain slopes and for revegetation programseconomic value with regards to the forests of An- on arid and deforested ranges, such as Sierra de Baza

´dalusia has yet to be assessed as a whole. Up till now, and Sierra de Gador. Depending on whether it be-the increasing economic importance of NTFPs in our comes commercially profitable to use its fruit forregion can only be inferred from ethnobotanical beverages, a program to control fruit harvesting and tostudies (Lange 1998; Font Quer 1961). avoid allochthonous introductions (P. spinosa) may be

necessary, especially in Sierra Nevada.Conservation and commercial efforts Until another certification system is applied in the

region, all Prunus germplasm, as well as other forestAs for goals regarding commercial activities and products from the region, will need a ‘certificate ofprofitability, P. avium is the most suitable species. Not origin’, issued by the regional Environmental Agency

´only does it provide timber that has a high market (Consejerıa de Medio Ambiente). This certificatevalue and is in high demand, it also produces some guarantees the origin, purity and sanitary conditionsimportant NTFPs, such as scented honey, medicinal of seeds and germplasm from Andalusia. It seems thatsubstances and fruit. Since this is the case, it clearly a preliminary Seed Zones Map has recently beenshould be proposed for a germplasm management issued for Spain, though it has not yet been published.plan with the aim of increasing both its timber quality Guideline 6: Scientific research to be done regard-and productivity. Therefore, a project to survey, col- ing the botany, wood quality improvement, non-lect and breed selected trees should be started, and timber forest products and rootstocks properties ofapproved seed orchards for seedling production and Prunus species.commercial production orchards should be estab- Though no scientific research in germplasm evalua-

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tion and breeding programs was done during recent important in P. avium, which has a considerable genedecades for most of the minor broadleaf tree species pool in the region. Both P. avium and P. mahaleb havein Spain, several current projects address these issues, a great future as minor hardwood species. Thesethough they are mainly being conducted in northern efforts will enhance public awareness, promote re-Spain (Puertas and Traver 1997; Traver et al. 1997; source management and launch silvicultural practicesVega 1996). They target P. avium as the most interest- aimed at the conservation of every Prunus species ining species, for its potential and the revenues it can Andalusia.produce. In several EU countries, similar breeding a) Conservation efforts should target the best popu-projects are being developed for P. avium (Depart- lations (of more than 20 individuals for P. avium andment of Forest Genetics of SLU in Sweden, INRA in P. insititia and more than 50 individuals of P. mahalebFrance, and in Germany). and P. spinosa), but the special conditions and the

In Spain, and primarily in Andalusia, further re- importance in the region of the first two species,search in Prunus germplasm should target the follow- oblige us to address all individuals, including the wilding topics: a) genetic variation studies of Prunus trees and local cultivars.species using modern tools (such as molecular b) The awareness of the importance of Prunusmarkers) should be undertaken in order to improve germplasm should be increased among forest work-our knowledge of the genetic structure of populations, ers, environmental managers and the public.help to better target conservation efforts and monitor c) For wild P. avium and P. insititia trees sufferingthe consequences of management plans; b) the de- introgression from domesticated material, highly di-lineation of climatic breeding zones, for Prunus and verse material coming from selected seed orchardsall forestry species; c) taxonomic studies of the P. should be planted in order to conserve the native wilddomestica-P. x fruticans-P. insititia complex; d) the genes among the natural populations.survey, collection and description (using IPGRI de- d) With the aim of enhancing Prunus conservation,scriptors) of cultivars and other naturalized material some silvicultural techniques are proposed, such asof P. avium, P. mahaleb and P. insititia in several of mixed Prunus patches, hedge treatment, Z-tree selec-the mountain ranges in Andalusia. No species is tion at the early stages and the protection of rootseverely endangered either locally or globally in the suckers.area, so the conservation of local Prunus cultivars that e) P. avium and P. mahaleb can be cultivated asstill survive should be the priority since they are high value timber trees. In this case, improved anddisappearing on a daily basis. The genetic studies selected germplasm should be used at highly prod-proposed may have a number of practical applications uctive sites. Other Prunus species can provide somefor the conservation of Prunus species, applications profitable NTFPs.that will differ depending upon the Prunus sub-group f) The main research to be done in the coming yearsto be implemented in. In the wild-naturalized-culti- is the evaluation and collection of the germplasm ofvated genetic pool of P. avium and P. insititia, differ- those species with greater economic importance, inent populations (those mentioned in the paper) could order to avoid, or at least mitigate, the rapid loss ofbe evaluated so as to determine their indigenous cultivars and the wild gene pool. No Prunus species ischaracter. Besides, in the undoubtful indigenous locally threatened in Andalusia at present.species (P. mahaleb, P. ramburii and P. spinosa) intra- Finally, we consider that global germplasm con-and inter-population variability can be assessed and servation schemes can provide a cost-effective way ofused to soundly ellaborate management plans for safeguarding the valuable genetic resources of An-germplasm conservation in the region. dalusian Prunus species. Other programs that are

more species-focused would be very expensive andtherefore not affordable for the regional government.

Conclusions

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