Toward the end of the first act, Astrov makes a long, impassioned speech in which he uses vivid imagery and pathos to persuade the other characters of the importance of conserving nature. The speech is sparked by Voynitsky's teasing comment that Astrov can't stop him from using wood for fuel and construction. Related to the symbol of forestry, Astrov's reflection on the senseless ecological destruction at the hands of humans becomes a motif in the play:
The forests of Russia are being wiped out by the axe, thousands of millions of trees are dying, the homes of animals and birds are being laid waste, river levels are dropping and drying up, wonderful scenery vanishes for ever, and all because lazy man hasn’t the sense to bend down and pick up fuel from the ground.
Astrov employs pathos to appeal to his listeners' emotions throughout the speech. He personifies the axe as well as the trees and animals, asserting that the latter have no chance against the deforestation caused by the former. Not only are trees dying and the homes of animals being destroyed, but the scenery that humans cherish is disappearing. However, it isn't really the personified axe that is to blame. Astrov eventually brings in the root cause of this widespread devastation: human laziness.
Lamenting the consequences of industrialization, Astrov critiques the idea that humans have the right to treat the earth however they please. Later in his speech, he touches on the irony that "man is endowed with reason and creative power in order to increase what he is given, but hitherto he has not created but destroyed." It is all because of humans that "every day the earth is becoming poorer and uglier."
Towards the end of his speech, Astrov comments on the skeptical facial expressions of the other characters. He defends his perspective with a final boost of pathos.
[...] but when I go past the peasants’ woods, which I saved from destruction, or when I hear the hum of my young trees, which I planted with my own hands, I know the climate is a little in my control and that if in a thousand years man is happy, the responsibility for that will in a small way be mine.
In certain ways, Astrov's pathos-filled speech is surprising. Other moments in the play characterize him as an exhausted, disillusioned doctor with a potential drinking problem. However, unlike Voynitsky and other dejected characters, Astrov has a cause that gives him purpose and hope. Seeking to make the planet livable for future generations, he watches the birches he plants and his "spirit fills with pride." The other characters don't seem to care much, but what is most important to him is that caring for the earth is a straightforward, actionable way to care for other people. Whereas Serebryakov and Voynitsky worry about the legacy of their achievements, Astrov sees his legacy as a way to make the earth more livable for future generations.
In the third act, Astrov tells Yelena about his map hobby. As with his speech about environmental conservation in the first act, this turns into a drawn-out speech describing a "portrait of our district as it was fifty years ago." Using detailed imagery, Astrov describes the maps he's been working on in detail to Yelena and the audience.
The dark and light green indicate forest; half of the whole area is covered by forest. Where there’s a red grid over the green, there were elk and wild goats… I show here both flora and fauna… This lake had swans, geese, duck, and as old folk say, a mighty eyeful of all kinds of wildfowl, which used to take off in a great storm cloud. [...] There were a lot of cattle and horses. You can tell that by the blue colour. For example, this unit of land has a thick layer of blue: here there were whole herds of horses and every household had three.
Astrov may personally be engaged as he describes the map to Yelena, but his description quickly turns dull. For both Yelena and the audience, the detail he goes into feels excruciating more than engaging. He recognizes this, ending his speech coldly: "I see by your expression this doesn't interest you." When Yelena defends herself, saying that she doesn't understand it, he tells her that it isn't a matter of understanding, but that "it's simply not interesting to you." Chekhov seems to be playing with Astrov's tediousness about map-making to reinforce his inability to connect with the people around him. He is the only character with a genuine passion for the world, but he is alone in his passion.
Colors become an important part of Astrov's description, as they code various features. Green means forest, red means wild animals, blue means farm animals. Touching on changes in agriculture, settlements, topography, flora, and fauna, his descriptions of the colorful patches on the map intermingle with descriptions of the actual landscape as it appeared in earlier decades. Astrov's map interest is ultimately related to his passion for forestry and environmental conservation.
He eventually compares the map of the district as it looked 50 years ago to a map of the same area as it looked 25 years ago. Using the colors, he demonstrates that the maps give a "a picture of gradual and definite decline, which clearly will take some ten to fifteen years to become total." He states that this decline would be understandable if the "destroyed forests" had been replaced by infrastructure and a higher quality of life, but the district has the "same lack of roads, poverty, typhus, diphtheria, fires" as ever before. He uses the maps to show that "now almost everything is destroyed, but nothing has yet been created to take its place." Astrov's map hobby may give him a sense of purpose and passion, but it ultimately reinforces his disillusionment with the world and the people around him.
This disillusionment can be understood alongside the characters' fixation on aging. Whereas Vanya and the Professor lament their own aging, Astrov laments nature's aging as a result of humanity's carelessness for the environment and other people—"a degeneration arising from stagnation, ignorance, a total lack of self-awareness."