HORNBEAM: species of tree, German: Weißbuche (literally 'white beech').
BTW, the beam in hornbeam was older English for tree (related to German Baum). English used to be much closer to German than it is today.
MICA£: one of many nickname-turned-surnames derived from Mikołaj (Nicholas); others include Micek, Micuła, Miciak, Mićka, Mika etc.
ZYCH: derived from first name Zygmunt or as topo nick from places such as Żychlin and Żychowo pronounced the peasant way — Zychlin and Zychowo respectively.
MAGIELSKI: could be derived from magiel (linen-pressing room) so Magielski would have been its owner or attendant; possibly also variant spelling of Magierski — a metronymic nick from magiera or megiera (a ****** old hag or shrew); but a magierka or madziarka was a Hungarian-style hat, so Magierski might have dennoted someone’s Hungarian connection.