There is an under current beneath Gustav Klimt's landscapes which speak of an individual who had concerns about the direction of nature at that time, specifically man's treatment of it. The natural world was a key element to his career, famously creating an indoor garden with his Stoclet Frieze multiple-panelled murals.
Klimt used the Tree of Life in that artwork, a symbol which has been used by all manner of religious teachings for thousands of years. This artist developed this motif to form his own symbolic work with in the Secession movement.
For much of his career exhibitions were key to the development of this artist, and this resulted in him producing many landscape works in purely square format, rather than landscape aspect ratio as most others would have done. His work in this genre was also far more consistent, stylistically, as compared to his other areas such as portraiture.
Klimt's modernist values ensure that there is a certain level of abstraction to be found in most of his landscape art, additionally the likes of Avenue of Schloss Kammer Park points specifically to the contemporary work of Egon Schiele, a close friend and colleague of Klimt.
Whilst Klimt and Schiele would spend time together in their studios, they would also peruse some of each other's unfinished landscapes as they would often bring them back home in order to add the final touches. At this point, influence from one to another is highly likely.
Landscape painting offered Gustav an opportunity to avoid directed commissions and take a little more control of his work. It also enabled the artist to escape to the countryside, and occasionally abroad.