BioInvasions Records (2017) Volume 6, Issue 1: 1–7 Open Access DOI: https://doi.org/10.3391/bir.2017.6.1.01 © 2017 The Author(s). Journal compilation © 2017 REABIC Rapid Communication Invasion of alien Prosopis species in Israel, the West Bank and western Jordan: characteristics, distribution and control perspectives Jean Marc Dufour-Dror1,* and Avi Shmida2 1Lifschitz College of Education, Department of Geography, Jerusalem, Israel 2The Institute of Life Sciences, The Hebrew University of Jerusalem, Israel *Corresponding author E-mail addresses: [email protected] (JMDD), [email protected] (AV) Received: 27 May 2016 / Accepted: 22 August 2016 / Published online: 12 September 2016 Handling editor: John Wilson Abstract The invasion history of alien Prosopis (mesquite) in Israel and Jordan is presented, with a detailed description of the introduction, background and the habitats now infested with Prosopis in these countries. While the number of escaped individuals in Israel is still limited, Prosopis has invaded large areas in Jordan and has become the main invasive alien tree in the Jordan valley. It is also now spreading in the canyons of south Jordan. The distinct prosopis invasion patterns in Israel and Jordan are discussed. Control programs are urgently needed in order to contain the proliferation of Prosopis, which now poses a major threat to natural habitats as well as to fallow fields. The ongoing establishment of dense thickets of Prosopis along wadis with year-round water flow is likely to displace native species such as Acacia raddiana Savi, and to alter the function of natural ecosystems. Key words: Mesquite, invasive species, Negev desert, Jordan valley, control Introduction stands, or even only thinning and pruning, could save up to 70 m3/ha/month (Dzikiti et al. 2013). Several Prosopis species are known as highly Prosopis invasion is well documented in many invasive taxa having severe negative impacts on tropical and subtropical regions but has not been natural ecosystems and agropastoral lands in Africa investigated so far in Israel and Jordan. and Asia (Witt 2010; Muturi et al. 2013; Sankaran and Suresh 2013; El-Keblawy and Abdelfatah 2014; Shackleton et al. 2014). Alien Prosopis species in Israel and Jordan The proliferation of invasive Prosopis species Distribution and introduction background has been reported to decrease local biodiversity among plant and bird species in various arid regions Israel’s arid and semi-arid regions, along with the (Dean et al. 2002; Berhanu and Tesfaye 2006; western part of Jordan, have been surveyed by the Schachtschneider and February 2013). The main authors since 1995, with special attention to natural impact of invasive Prosopis on natural ecosystems and semi-natural sites where the presence of alien occurs through competition for groundwater: Prosopis individuals was mentioned or reported by prosopis’ deep and extensive root systems lead to the botanists (Pasiecznik et al. 2001; Ravak and Shmida depleting of groundwater reserves in water-scarce 2013). The regions investigated in Israel included: environments, which inevitably causes native trees the Jordan Valley, the Dead Sea area, the Negev such as Acacia tortilis (Forssk.) Hayne, Hyphaene desert, the Arava Valley, and the Gulf of Eilat area. compressa H.Wendl., or Acacia erioloba E.Mey. to The regions surveyed in Jordan extended from the dry out (Boy and Witt 2013; Schachtschneider and Irbid district in the north to the Al Aqabah area in February 2013; Shackleton et al. 2015a;). A recent the south, as well as the western part of the Ma’an study carried out in the Northern Cape region (of district. The region of Azraq and eastwards was not South Africa) suggests that clearing invasive Prosopis investigated. 1 J.M. Dufour-Dror and A. Shmida The alien Prosopis species that have been planted from the Dead Sea area to the south, 18 have in Jordan and Israel were recorded as Prosopis affinis permanent water flow, and half (9) of these are already Spreng., P. alba Griseb., P. articulata S.Watson, P. infested with alien Prosopis (Ravak and Shmida chilensis (Molina) Stuntz, P. glandulosa Torr., P. 2013). In the Jordan Valley, from the Dead Sea to the juliflora (Sw.) DC., P. nigra Hieron., P. pallida Yarmouk river, P. juliflora is widespread, occurring (Willd.) Kurth, and P. velutina Wooton (Shalmon along wadi beds, roadsides, agricultural fields, and 2003; Kutiel 2004). The identification was made by disturbed habitats. It grows also in undisturbed, the authors according to Pasiecznik et al. (2001, natural, dry, rocky habitats. 2004), according to Burkart’s monograph (1976), Benson (1941), and Townsend and Guest (1974). All Israel the specimens deposited as voucher material at the Since the 1960s several alien species of Prosopis herbarium of the Hebrew University of Jerusalem have been checked (Supplementary material, Table S1). have been introduced into Israel by the Forestry Department of the Jewish National Fund (JNF) for ornamental and environmental purposes in the semi- Western Jordan arid and arid regions of the country (Shalmon 2003; Alien Prosopis were introduced during the 1980s to Kutiel 2004). The majority of trees that were planted Jordan, and planted along roadsides in the Rift in Israel have been named P. nigra (auct). However, valley and the Rhur (Banan Al-Sheikh, pers. comm.) we have identified most of the escaped and planted The Jordan Forestry Department planted mostly P. Prosopis individuals as P. juliflora and P. alba juliflora. P. alba plantations are very rare and have (Figure 1). been observed in very few locations. We do not have According to the identification key of Burkart’s direct observations about Prosopis prior to 1994 in monograph (1976), all the Prosopis species intro- Jordan since the peace treaty between Israel and duced into Israel belong to Section ALGAROBIA, Jordan was signed that year. Series Chilenses, i.e., P. juliflora, P. alba, P. chiliensis, All escaped Prosopis individuals recorded in P. nigra, P. glandulosa, and P. velutina. Most of Jordan were identified as P. juliflora. We did not these taxa were treated by Pasiecznik et al. (2001) as record escaped individuals of P. alba. In February a P. juliflora – P. pallida complex and we refer to 1996 we have observed the first naturalized indivi- them in this note as P. juliflora. Already in 1941 duals close to a roadside, in the Zarqa Ma’in resort Benson carried out a thorough survey in the southern area (Figure 1), next to recently planted individuals U.S. and concluded that P. glandulosa, P. velutina, along the road. This focus included up to 30 young and P. torreyana are varieties of one species. individuals less than 1 m tall. In the following years The Prosopis individuals that escaped planted new individuals were recorded along the wadi bed of plots and became naturalized in Israel were identified wadi Zarqa Ma’in, from the recreation area down to as P. juliflora characterized by long thin and almost the Dead Sea, the latest record being made in 2013. straight pods, usually acuminate (Pasiecznik et al. Similar invasion patterns were recorded within the 2004). It should be stressed that except for the fruit, canyons of southern Jordan, from wadi Hizban in the all the other diagnosed characters, especially the north to wadi Musa in the south. leaves, are highly variable in shape among individuals A first specimen of P. juliflora was recorded in within a given population. the flood plain of wadi Assal, 27 km southwest of Most of the Prosopis species were planted since Karak, in 1997. Additional individuals of P. juliflora the 1960s in the arid and the semi-arid regions of were recorded in the adjacent canyon of wadi Assal Israel, mainly in the Negev desert and in the central and wadi Hudeira, next to the potash plant, in 2001. and southern Jordan valley. Almost all Prosopis In 1998 a new road was constructed between the individuals that established in the wild were cities of Peifeh and Tafila. Shortly thereafter, several recorded in the semiarid region: in the southern individuals established along the road and into coastal plain, in the western Negev, and locally in the nearby irrigated agricultural fields. Since then, P. northern Negev region. The majority of naturalized juliflora has expanded and formed a savanna-like individuals of Prosopis in Israel are found north and stand in the wadi Assal and wadi Hudeira floodplains. west of the city of Beer-Sheva in the northern Negev The occurrence of P. juliflora stands in the Dead (Shalmon 2003; Blecher and Blecher 2010), where Sea region of Jordan is restricted to wadi beds with Prosopis established in wadi beds on limestone permanent water flow and irrigated fields. The outcrops as well as in depressions within the loess permanent water flow originates from natural springs hilly areas characteristic of this region. Prosopis trees along the canyons. Out of the 31 canyons found rarely grow outside wadis in Israel. 2 Invasion of alien Prosopis species in Israel, the West Bank and western Jordan Figure 1. Distribution of Prosopis spp. in Israel, the West Bank and western Jordan (see details in the supplementary material Table S2 and Table S3). 3 J.M. Dufour-Dror and A. Shmida Figure 2. Dense thicket of Prosopis juliflora in wadi Ashan in the Beer-Sheva area (Israel) (Photo: J.M. Dufour-Dror). The densest stands are found in wadi Ashan (Figure were planted in the late 1980s. However, two main 2), wadi Patish, and wadi Besor, 2–15 km northwest determinants may explain the distinct invasive patterns of Beer-Sheva (Figure 1). Very few individuals were between Jordan and Israel: recorded south of the 100 mm isohyet as only (1) The first is related to the humidity conditions several individuals were found in the southern Arava of habitats sensitive to Prosopis establishment and region, next to irrigated fields and along roadsides.