Map 2). It is likely, therefore, that when Cyrus the Younger passed through, any pastoral nomads that might have frequented the region in winter had long since moved north to more temperate areas in Anatolia.
Later Greek sources compiled in the wake of Alexander's conquest provide a snapshot of environments found in the different satrapies of the Achaemenid Empire, naming rivers, mountain ranges, and other notable physical features as well as resources. The lost but heavily cited Geographika of Eratosthenes (Roller 2010), the later compendium of Strabo (Biffi 2002), and the histories of Alexander's campaigns (especially Arrian's Anabasis) are invaluable sources of material on the landscapes of the late Achaemenid Empire. Even some of the most arid regions, like Gedrosia, produced economically (and medicinally) important resources. The flora of Gedrosia was described in considerable detail by Theophrastus (Theophrastus, Hist. Plant. 4.4.12–13; cf. Arrian, Anab. 6.22.4–8; Strabo, Geog. 15.2.3; Pliny, Nat. Hist. 12.33) and included, in the interior, a myrrh‐like aromatic (bdellium), triangular spurge (Euphorbium antiquorum), spikenard (sweet rush or ginger grass, Cymbopogon schoenanthus), asafoetida (Scorodosma foetidum), oleander (Nerium odorum), and the date palm (Phoenix dactylifera) as well as mangrove (Avicennia marina) along the coast (Eggermont 1975: pp. 120–125; cf. Bretzl 1903). Many of these species were found in Aria, Arachosia, and Parapamisadae as well (Eggermont 1975: p. 123). Such accounts, while valuable, obviously present only the smallest fraction of the economically valuable flora, let alone the complete flora of these areas. There were many more species of great utility that went unmentioned, as a glance at the literature on the economic botany of, for example, eastern Iran clearly shows (Aitchison 1890). To mention just one wood that was highly prized for woodworking, Pakistani rosewood (Dalbergia sissoo), known widely as sissoo throughout the region, went unmentioned, although it was common throughout the Indo‐Iranian borderlands (Tengberg and Potts 1999).
Finally, archeological and in particular archeobotanical and paleoenvironmental studies at individual sites, along with regional surveys, have contributed to our knowledge of the climate and environment of the Achaemenid Empire. Studies around Gordion, in the ancient satrapy of Phrygia, for example, point to the existence of extensive non‐deciduous forests, containing pine (Pinus sylvestris), cedar (Cedrus libani), and yew (Taxus baccata), around the site about 2500 years ago (Erinç 1978: p. 97). Deforestation of these forests only began later, accelerating during the Roman period (Brice 1978).
It is clear from analyses of cores taken from Lakes Zeribar and Mirabad in northwestern Iran that there are few signs of climatic fluctuation in the region after about 3500 BCE (van Zeist 1967: pp. 310–311; Bottema 1986: p. 259; Jones 2013). Moreover, those indications of climatic shifts that do appear at Lake Mirabad all postdate the Achaemenid period (Griffiths et al. 2001: p. 761).
However, all across the Achaemenid Empire human intervention and modification of the landscape also must have played a role. This would have included the alteration of ecosystems through agricultural intensification, including olive cultivation in Fars (Jones et al. 2015; Djamali et al. 2016) and the expansion of irrigation systems involving the building of dams, qanats, and canals. There is a widespread if often unacknowledged belief that agricultural intensification was actively pursued by the Achaemenids, e.g. in the Deh Luran region, which lay astride the Royal Road between Susa and Babylon (Wright and Neely 2010: Fig. 6.6), but water management features are notoriously difficult to date, particularly when local masonry styles are not easily attributed to a particular period and commemorative or foundation inscriptions are absent (Boucharlat 2001: p. 178). Thus, the attribution of hydraulic features, attested archeologically, to the Achaemenid period is difficult. Moreover, even when hydraulic works mentioned in cuneiform or literary sources, or discovered in excavation, can be dated to the Achaemenid period, it is often unclear whether they resulted from centrally mandated imperial or locally driven investment, or indeed from a combination of the two. Evidence of local investment spurred by central governmental incentives can be found in Polybius' well‐known discussion of qanats in Media. According to Polybius (History 10.28), “in this tract of country there is no water (anhydria) appearing on the surface, though there are many subterranean channels (hyponomoi) which have well‐shafts (phreatiai) sunk to them, at spots in the desert unknown to persons unacquainted with the district. A true account of these channels has been preserved among the natives to the effect that, during the Persian ascendancy, they granted the enjoyment of the profits to the inhabitants of some of the waterless districts for five generations, on the condition of their bringing fresh water in; and that, there being many large streams flowing down Mount Taurus [Alburz], these people at infinite toil and expense constructed these underground channels through a long tract of country in such a way that the very people who now use the water are ignorant of the sources from which the channels are originally supplied.”
This clearly indicates that the Achaemenid government actively provided incentives for local investment in qanat construction and maintenance in Media. Less certain is whether or not the same policy operated elsewhere in the empire. Many scholars have inferred from Polybius' statement that under the Achaemenids, “qanat technology spread well beyond the confines of the Iranian Plateau” and, as a result of the policy of land grants, “thousands of new settlements were established and others expanded” as “qanats were constructed from Mesopotamia to the shores of the Mediterranean as well as southward into parts of Egypt and Arabia” (English 1998: p. 189; cf. Goblot 1979: pp. 70–71; Rahimi‐Laridjani 1988: pp. 445–447; Lightfoot 2000: p. 218). As Briant has stressed, however, it is important to remember that Polybius explicitly attributed the investment in qanats to private enterprise, rewarded with long‐term land tenure (over five generations), not state investment (Briant 2001: p. 18). The recently excavated qanat system at ‘Ayn Manāwīr in the Kharga Oasis (Egypt), constructed during the fifth century BCE according to Demotic ostraca dated in the reigns of Artaxerxes I and Darius II, may reflect “a decision issued from the court at Memphis” and “could have been the decision of the Persian central power under the control of the Satrap of Egypt and his administration” (Wuttmann et al. 2000: pp. 3–5), but this is far from proven. A decentralized approach to water capture and management, even if disseminated from the top down, may have been left to local administrators to implement (Cruz‐Uribe 2003: p. 543).
Even in Babylonia, a satrapy of central importance, both fiscally and agriculturally, to the Achaemenid crown, “the extent to which the crown itself was responsible for the improvements in the [irrigation] system rather than merely benefiting from them by right of conquest” is unclear (Adams 1981: p. 187). Although A.L. Oppenheim believed that Achaemenid Babylonia was characterized by “new installations, new techniques, [and] better utilization of the available water” (Oppenheim 1985: p. 578), and the Great King owned many canals (Dandamayev 1992: p. 13), it is not always clear whether the contributions of the crown to canal construction were greater than those of private landowners (Joannès 2004: pp. 214–216). Indeed, in comparison with the number of references to canal construction and maintenance in the Neo‐Babylonian period credited to individual kings (Cole and Gasche 1999: pp. 102–105), the paucity of references in the Achaemenid period could be construed as a sign that the Achaemenids were content to use the infrastructure they had inherited in Babylonia without investing much in the upkeep or expansion of the canal system themselves, notwithstanding the fact that the agricultural yields there continued to be impressive (Wiesehöfer 1999: p. 174). This, however, would be wrong. Like their predecessors, the Achaemenid administrators responsible for Babylonia attended to the upkeep and expansion of the irrigation network, but they were able to see that the great institutions in the land, principally the temples, bore the lion's share of the costs. Thus, in one text concerning a rent farmer, dated to the second year of Darius I's reign, reference is made to “digging on the main canals at the expense of the treasury of Eanna” (i.e. the large temple complex at Uruk). Another text (Dar. 9) from the reign of Darius attests to the involvement of the Shamash temple at Sippar in the digging and cleaning of canals that ran through its property, as well as the involvement of a consortium identified as “the chiefs of the chariots” (van Driel 1988: p. 129, citing TCL 13: 182). In van Driel's opinion, these were major maintenance projects “supervised by the royal administration which shared out the burden among the great institutional and private