Règle correspondante
Practice Relating to Rule 147. Reprisals against Protected Objects
Section E. Natural environment
Germany’s Military Manual (1992), referring to Article 55(2) of the 1977 Additional Protocol I, provides: “It is expressly prohibited by agreement to make reprisals against: … the natural environment.” 
Germany, Humanitarian Law in Armed Conflicts – Manual, DSK VV207320067, edited by The Federal Ministry of Defence of the Federal Republic of Germany, VR II 3, August 1992, English translation of ZDv 15/2, Humanitäres Völkerrecht in bewaffneten KonfliktenHandbuch, August 1992, § 479.
Germany’s IHL Manual (1996) provides: “Reprisals are expressly prohibited against … the natural environment”. 
Germany, ZDv 15/1, Humanitäres Völkerrecht in bewaffneten Konflikten – Grundsätze, DSK VV230120023, Bundesministerium der Verteidigung, June 1996, § 320.
In 1990, in a parliamentary debate on the ratification of the 1977 Additional Protocols, a member of the German Parliament called the prohibition of reprisals as contained in the Additional Protocol I “newly introduced rules”. 
Germany, Lower House of Parliament, Speech by Günter Verheugen, Member of Parliament, 20 September 1990, Plenarprotokoll 11/226, p. 17919.
Upon ratification of the 1977 Additional Protocol I, Germany declared:
The Federal Republic of Germany will react against serious and systematic violations of the obligations imposed by Additional Protocol I … with all means admissible under international law in order to prevent any further violation. 
Germany, Declarations made upon ratification of the 1977 Additional Protocol I, 14 February 1991, § 6.