Phytoplankton biomass, expressed as chlorophyll a concentration, reflects nutrient loading in the marine environment. Chlorophyll a concentrations shows a trend towards improvement in the status of the Slovenian sea, as the ecological status has been assessed as high or good over the last period.

Deadwood is an important animal and plant habitat that contributes to the biodiversity of forest ecosystems. According to Slovenia Forest Service data, the volume of standing and fallen trees without stumps and branches in 2022 was 21.3 m³/ha, which represented approximately 6% of the entire wood stock of forest stands. In virgin forests, however, the deadwood volume can be even several dozen times greater.

In the past centuries, forest area has been increasing constantly after 2010; however, the rate of expansion has slowed down and remains relatively stable in recent years. Since 1875, when forests covered only 36% of the Slovenian territory, forest cover has increased to 58.5% in the year 2009 and rests stable today at 58.0 %. In terms of forest share, Slovenia ranks third among EU-28 countries, behind Sweden and Finland.

Regarding the forest area, deforestation accounts for an insignificant share. The average of the last ten years is approximately 405 ha (350–550 ha per year) and thus does not represent a significant factor in forest cover changes. Until 2008, most deforestation is a result of infrastructure facilities construction. In 2008, the unprecedented increase in deforestation for agricultural purposes occurred. The increase was due to the amendment to the Forest Act, which subject to the conditions allows the issuance of an authorisation for deforestation for agricultural purposes up to 0.5 ha.

In Slovenia, forests have been growing in terms of growing stock and increment for decades. They have increased by more than 140% over the last 70 years. In addition to natural conditions, harvesting depends on socioeconomic factors, and recently on the occurrence of natural disasters (windbreaks, icebreakers) and bark beetles outbreaks. By 2014, the felling accounted for about 50% of the increment. After the ice storm in 2014, it increased substantially and accounted for 60 to 75% of the total increment of conifers and deciduous trees.