Conservation Responsibility for Priority Habitats under Future Climate Conditions: A Case Study on Juniperus drupacea Forests in Greece

Abstract

Juniperus drupacea is a highly morphologically and genetically differentiated Tertiary relict, displaying a disjunct geographical range in the eastern Mediterranean. Being a thermophilous, light-demanding, and moderately drought-resistant tree, it survived the past climatic oscillations via altitudinal migration. The species has its westernmost range limit, and its only populations in the EU, in Mts Parnon and Taygetos (Greece). These populations are genetically isolated and distinct compared to their Asian counterparts. For Europe, Juniperus drupacea is categorized as an endangered species by the IUCN. Juniperus drupacea forests constitute a priority habitat for conservation in the EU. However, the species’ conservation status has never been assessed in Greece and the same applies to its climate and land-use change assessment. As Greece is already facing the short-term impacts of climate- and human-induced land-use change, studies dealing with the potential long-term climate- and land-use change effects on rare plant species distribution are urgently needed to implement efficient conservation management plans. Our research employs species distribution models, considering multiple climate scenarios and abiotic factors across different timeframes (2020s, 2050s, 2080s), factoring in the potential threat of forest fires. Additionally, we assess the species’ extinction risk at the European level, according to IUCN Criteria A and B. Study findings indicate significant habitat changes and an elevated extinction risk for Juniperus drupacea in Greece. To safeguard this priority habitat, informed conservation strategies, management plans, and policy making are recommended, based on our scientific insights.

Rising Temperatures, Falling Leaves: Predicting the Fate of Cyprus’s Endemic Oak under Climate and Land Use Change

“…Dynamic variables such as land-use cover, albeit exhibiting low temporal variability within the study area ( Figure 2 , Figure 3 and Figure S1–S13 ), are ecologically crucial factors affecting habitat suitability and model accuracy and precision in Quercus alnifolia ( Table S2; Figure S14 ) and other oaks and endemic or range-restricted plants [ 10 , 11 , 12 , 41 ]. While our models revealed greater sensitivity to land-use variables than climatic variables, current forecasts indicate minimal anticipated land-use change within Quercus alnifolia ’s range ( Figure 2 , Figure 3 and Figure S1–S13 ).…”

“…Mediterranean trees inhabiting mountainous regions face considerable risk of habitat loss under shifting climate regimes [ 16 , 45 ]. This potential reduction is particularly acute for range-restricted and endemic species [ 11 , 13 ] and is especially true for one of the largest tree genera [ 39 ], Quercus , as climate change is one of the major threats oaks will face in the future [ 42 , 44 ]. Forecasts indicate a contraction in the habitats of certain oak species across the Mediterranean [ 13 , 14 , 38 , 108 ].…”

“…The Mediterranean Basin, recognised both as a global biodiversity hotspot [ 4 ] and a climate change hotspot [ 5 , 6 ], epitomises these challenges. It has already manifested ecological shifts, including phenological alterations [ 7 ], reduced provision of regulating ecosystem services [ 8 ], and species loss [ 9 , 10 , 11 , 12 , 13 , 14 ], with these alterations predicted to intensify, especially in Mediterranean forests [ 8 , 15 , 16 ]. Conversely, land-use modification has emerged as a primary factor in plant extinctions over recent centuries [ 17 ], significantly transforming continental Europe’s vegetation [ 18 ] and causing excessive soil erosion in Mediterranean forests [ 5 ].…”

“…Climate change is one of the major threats oaks will face in the future, despite having survived several unfavourable periods since their emergence 55 Mya [ 43 , 44 ]. Research has also probed into other genera, including Pinus [ 45 ], Juniperus [ 11 , 14 ], Abies [ 14 , 46 , 47 ], and Cedrus [ 46 , 48 ], with the primary emphasis being on the western Mediterranean and the eastern Mediterranean countries, encompassing Asia Minor and the Levantine coast (i.e., Turkey, Israel, Lebanon, and Egypt). Climate change thus threatens the habitat suitability, growth, regeneration capacity, and distribution ranges of many Mediterranean tree species [ 49 ], and increased drought stress and extreme heat are expected to cause tree growth declines, higher mortality risks, and increasing disturbance from fires, pests, and diseases [ 50 ].…”

“…By incorporating these projections, our study not only addresses a critical gap in current ecological models but also offers a more comprehensive understanding of the multifaceted pressures on Quercus alnifolia , a species intrinsically linked with soil stabilisation in the Troodos mountain range, laying the groundwork for targeted conservation efforts amidst rapidly changing environmental conditions. Our research builds upon previous studies in Greece [ 10 , 11 , 12 ] integrating land use and land cover (LULC) data into climate change vulnerability assessments (CCVAs). It is the first in Cyprus and the eastern Mediterranean to explicitly combine LULC with hydrological and soil erosion data, as recommended by [ 98 ].…”