The first gambier and pepper plantations appeared in Southern Johor, notably Skudai. Lau Lib Keng, a Chinese settler based in Skudai, was the first person to receive a "Surat Sungai", whereby the river banks of Skudai were leased to Lau for the cultivation of gambier and pepper. More Chinese settlers came to Johor from the 1850s onwards, and forested areas in Southern Johor such as Tebrau, Plentong and Stulang were cleared for the cultivation of gambier and pepper. By the time Temenggong Daeng Ibrahim's son, Abu Bakar took office from his father in 1862, at least 37 "Surat Sungai" have been issued to various Kangchu, all of whom were collectively responsible for the operations of the 1,200 gambier and pepper farms in the state. Most of these Chinese leaders were also members of secret societies, and communal warfare often broke out in Singapore between different dialect groups as a result of conflicting economic interests. From the late 1850s onwards, the Kangchu began to exert political influence in the state affairs by establishing close ties with Temenggong Abu Bakar. In 1865, Abu Bakar granted official recognition to the Teochew-dominated Johor branch of the Ngee Heng Kongsi after a Kangchu, Tan Kee Soon, raised a small army to subdue Sultan Ali's forces, from whom Abu Bakar was facing considerable dissent but was unable to raise an organised army. Abu Bakar nevertheless called for the Ngee Heng Kongsi to accept Chinese settlers of other dialect groups to prevent possible communal warfare as a result of conflicting economic interests.