Understanding diversity patterns along environmental gradients and their underlying mechanisms is a major topic in current biodiversity research. In this study, we investigate for the first time elevational patterns of vascular plant species richness and endemism on a long-isolated continental island (Crete) that has experienced extensive post-isolation mountain uplift. We used all available data on distribution and elevational ranges of the Cretan plants to interpolate their presence between minimum and maximum elevations in 100-m elevational intervals, along the entire elevational gradient of Crete (0–2400 m). We evaluate the influence of elevation, area, mid-domain effect, elevational Rapoport effect and the post-isolation mountain uplift on plant species richness and endemism elevational patterns. Furthermore, we test the influence of the island condition and the post-isolation mountain uplift to the elevational range sizes of the Cretan plants, using the Peloponnese as a continental control area. Total species richness monotonically decreases with increasing elevation, while endemic species richness has a unimodal response to elevation showing a peak at mid-elevation intervals. Area alone explains a significant amount of variation in species richness along the elevational gradient. Mid-domain effect is not the underlying mechanism of the elevational gradient of plant species richness in Crete, and Rapoport's rule only partly explains the observed patterns. Our results are largely congruent with the post-isolation uplift of the Cretan mountains and their colonization mainly by the available lowland vascular plant species, as high-elevation specialists are almost lacking from the Cretan flora. The increase in the proportion of Cretan endemics with increasing elevation can only be regarded as a result of diversification processes towards Cretan mountains (especially mid-elevation areas), supported by elevation-driven ecological isolation. Cretan plants have experienced elevational range expansion compared to the continental control area, as a result of ecological release triggered by increased species impoverishment with increasing elevation.

Grasslands, wet meadows, fens, bogs, and marshes represent important ecosystems that host many orchid species. However, research on the joint effect of the multi-scalar abiotic drivers on orchid distribution and abundance in these habitats is limited. In this study, we investigated factors associated with the occurrence and abundance of 42 orchid taxa in grasslands and herbaceous wetlands of 29 mountains and the surrounding low altitude areas in western Serbia (eastern Dinaric Alps, southeastern Europe). Niche analysis of orchids was performed using outlying mean index analysis (OMI). In addition, we used similarity profile analysis (SIMPROF) to classify orchid taxa into ecological groups, multi response permutation procedure (MRPP) to analyse the differences in orchid composition between vegetation types, and indicator species analysis (ISA) to detect orchids with an affinity to a certain type of vegetation and geological bedrock. The most important gradients that separate orchids within the sampled environmental conditions were moisture, temperature, altitude and soil pH. Moreover, this study underlines the importance of certain vegetation types and geological bedrocks in determining the distribution and abundance of orchids. In total, eight ecological groups of orchids were distinguished. The results have shown that 11 orchid taxa are indicators of specific vegetation types, whereas 13 orchid taxa are indicators of specific bedrock types. The study area provides suitable conditions for survival of some rare and endemic orchid species that have southern limits of their distribution in this part of southeastern Europe. The study suggests that the joint effect of ecological factors, especially vegetation communities and bedrock types, is important to consider in the planning and management of orchid species conservation.

Biotic interactions play an important role in species distribution models, whose ignorance may cause an overestimation of species' potential distributions. Species of the family Orchidaceae are almost totally dependent on mycorrhizal symbionts and pollinators, with sexually deceptive orchids being often highly specialized, and thus the interactions with their pollinators are expected to strongly affect distribution predictions. We used Maxent algorithm to explore the extent of current and future habitat suitability for two Greek endemic sexually deceptive orchids (Ophrys argolicaandOphrys delphinensis) in relation to the potential distribution of their unique pollinator (Anthophora plagiata). Twelve climate change scenarios were used to predict future distributions. Results indicated that the most important factors determining potential distribution were precipitation seasonality forO. argolicaand geological substrate forO. delphinensis. The current potential distribution of the two orchids was almost of the same extent but spatially different, without accounting for their interaction withA. plagiata. When the interaction was included in the models, their potentially suitable area decreased for both species. Under future climatic conditions, the effects of the orchid-pollinator interaction were more intense. Specifically,O. argolicawas restricted in specific areas of southern Greece, whereasO. delphinensiswas expected to become extinct. Our findings highlighted the significant role of plant–pollinator interactions in species distribution models. Failing to study such interactions might expose plant species to serious conservation issues.

Dactylorhiza hatagirea is a terrestrial orchid listed in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and classified as threatened by International Union for Conservation of Nature (IUCN). It is endemic to the Hindu-Kush Himalayan region, distributed from Pakistan to China. The main threat to its existence is climate change and the associated change in the distribution of its suitable habitats to higher altitudes due to increasing temperature. It is therefore necessary to determine the habitats that are suitable for its survival and their expected distribution after the predicted changes in climate. To do this, we use Maxent modelling of the data for its 208 locations. We predict its distribution in 2050 and 2070 using four climate change models and two greenhouse gas concentration trajectories. This revealed severe losses of suitable habitat in Nepal, in which, under the worst scenario, there will be a 71–81% reduction the number of suitable locations for D. hatagirea by 2050 and 95–98% by 2070. Under the most favorable scenario, this reduction will be 65–85% by 2070. The intermediate greenhouse gas concentration trajectory surprisingly would result in a greater reduction by 2070 than the worst-case scenario. Our results provide important guidelines that local authorities interested in conserving this species could use to select areas that need to be protected now and in the future.