Peter Brown, Augustine of Hippo
(Berkeley: University of California Press, 1969; rpt. 1975), p. 20:
These sturdy planters, suspicious of the outside world, living in tight-knit communities, whose habits had changed little since pre-historic times, had become the arbiters of the prosperity of Africa: 'Here lies Dion, a pious man; he lived 80 years and planted 4000 trees.'2
2Inscriptions latines de la Tunisie, no. 243; v. esp. Frend, Donatist Church, pp. 38-47.
I don't have access to the sources cited by Brown, so I can't quote the original Latin inscription. On tree planting by an old man as an act of piety, see Cicero, On Old Age
They expend effort on things which they know won't benefit them at all: "He plants trees to benefit another age," as our Caecilius Statius says in his Young Comrades. If you ask a farmer, no matter how old he is, for whom he's planting, he doesn't hesitate to say, "For the immortal gods, who not only were willing for me to receive these things from my ancestors, but also for me to hand them on to my descendants."
in eis elaborant, quae sciunt nihil ad se omnino pertinere: "serit arbores, quae altero saeclo prosint," ut ait Statius noster in Synephebis. nec vero dubitat agricola, quamvis sit senex, quaerenti cui serat respondere: "dis immortalibus, qui me non accipere modo haec a maioribus voluerunt, sed etiam posteris prodere."
Related post: Planting Trees