Yosef Weitz (1890–1972) was the director of the Land and Afforestation Department of the Jewish National Fund. From the 1930s, Weitz played a major role in acquiring land for the Yishuv, the pre-state Jewish community in Palestine.
Weitz was born in Burmel, Volhynia in 1890. In 1908, he immigrated to Palestine with his sister, Miriam, and found employment as a watchman and an agricultural laborer in Rehovot. In 1911, he was one of the organizers of the Union of Agricultural Laborers in Eretz Yisrael. Weitz married Ruhama and their eldest son, Ra'anan, was born in 1913. Two years later, in 1915, he was appointed foreman of the Sejera training farm (now Ilaniya) in the Lower Galilee. Weitz helped to found Yavniel, one of the first pioneer colonies in the Galilee, and later, the Beit Hakerem neighborhood in Jerusalem. His son Yehiam (Hebrew for "Long Live the Nation"), born in October 1918, was killed in a Palmach operation on June 16, 1946. Kibbutz Yehiam was established in his memory. Sharon Weitz, another son, followed in his father's footsteps and later took over as director of the Forestry Department. In his memory was named the Ma'ale Yosef Regional Council and the moshav Talmei Yosef.
As head of the JNF Forestry Department, Weitz put his visions of Israel as a forested country into practice. He was spurred on by David Ben-Gurion, who told Weitz he wanted a billion trees planted within a decade. In 1949, he proposed a division of labor between the Israeli government and the JNF. The government would engage in applied research in planting techniques, especially in arid areas, and the development of a timber industry. It would also establish nurseries. The JNF would improve indigenous forests, work in afforestation of hilly regions, stop the encroachment of sand dunes and plant windbreakers. Weitz saw plant nurseries and afforestation as a vital source of employment for the masses of new immigrants arriving in the early days of the state. He was guided by the belief that developing a work ethic was imperative for acculturation.
In 1966, Yatir Forest in the Negev was planted at Weitz's urging. He described the project as "rolling back the desert with trees, creating a security zone for the people of Israel."  Named for the biblical town of Yatir, it is now Israel's largest planted forest.
Weitz’s never formally studied forestry but his autodidactic perspective was reflective of the period. The forestry strategy he crafted emphasized the economic utility of forests and the importance of the Aleppo pine as the hardiest of local species. As a result, Israel’s forests for its first twenty years were largely mono cultures which would soon suffer serious losses due to natural pests. Weitz frequently clashed with the nascent conservation movement in Israel which found the industrial approach to tree planting that the Jewish National Fund adopted to be objectionable. Today, many of Weitz’s ideas have been replaced with more sustainable approaches to foresting.
Weitz was an advocate of population transfer. On June 22, 1941 he wrote in his diary: "The land of Israel is not small at all, if only the Arabs were removed, and its frontiers enlarged a little, to the north up to the Litani, and to the east including the Golan Heights...with the Arabs transferred to northern Syria and Iraq...Today we have no other alternative...We will not live here with Arabs."
According to Ilan Pappe, passages in Weitz's diary in April 1948 show his support for the transfer of Arabs during the 1948 war: "I have drawn up a list of Arab villages which in my opinion must be cleared out in order to complete Jewish regions. I have also drawn up a list of land disputes that must be settled by military means." According to Efraim Karsh, Ben-Gurion rejected the idea, and no such committee was ever established. Nevertheless, Nur Masalha and Benny Morris claim an unofficial Transfer Committee was established in May 1948 composed of Weitz, Danin and Sasson.Later in life, Weitz's views appear to be more conciliatory towards the neighboring Arabs and he is reported to have refused to attend ceremonies of renew Jewish settlements in the West Bank after the 1967 war.
- My Diary and Letters to the Children, vols 1-6, Masada, Ramat Gan, 1965, 1973 (the original diaries are in the Central Zionist Archives in Jerusalem).
- HaYa'ar V'haYiur B'Yisrael (The Forest and Forestry in Israel), Masada, Ramat Gan, 1970 p. 140-141.
- Journal entry from June 26, 1946 published in Tlamim Ahronim, Jerusalem, Keren Kayemet, 1974, p. 24-25.
- From Small to Large - The History of Land Reclamation in Eretz-Israel, Ramat Gan, 1972
- Creating a Land Legacy - Chapters from a Diary, Tel Aviv, 1951
- Our Settlement Activities in a Period of Storm and Stress, 1936-1947, Tel Aviv, 1947
- Encyclopedia Judaica, "Weitz, Joseph," vol. 16, p. 421, Keter, 1972
- Tom Segev, "1967, Israel, the War, and the Year that Transformed the Middle East", 
- Pollution in a promised land: An environmental history of Israel, Alon Tal, p. 89
- Jewish National Fund (February 22, 2010). "Beersheba River Park with KKL-JNF on World Environment Day". The Jerusalem Post. Retrieved 2010-06-11.
- Masalha, 1992, p. 134-135
- Pappe, 2006, p. 61-64
- Weitz Diary, 18 April 1948, p. 2358, Central Zionist Archives, Jerusalem
- "Benny Morris and the Reign of Error" http://www.meforum.org/article/466
- Masalha, 1992, "Expulsion of the Palestinians", p. 188
- B. Morris, "The Birth of the Palestinian Refugee Problem Revisited", 2004, p. 312
- Nur Masalha (1992). Expulsion of the Palestinians: The Concept of "Transfer" in Zionist Political Thought, 1882-1948, Institute for Palestine Studies, ISBN 0-88728-235-0
- Benny Morris: 1948 and after; Israel and the Palestinians, 1994, chapter 4: Yosef Weitz and the Transfer Committees, 1948-1949.
- Alon Tal, Pollution in a Promised Land, An Environmental History of Israel, University of California Press, Berkeley, 2002.
- Tom Segev, 1949, The First Israelis, New York, The Free Press, 1986, p. 29-30.