Editing IPCC:AR6/WGII/Chapter-13 (section)

==== 13.3.1.4 Observed Impacts and Projected Risks on Ecosystem Functions and Regulating Services ====

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European temperate and boreal forests, wetlands and peatlands hold important carbon stocks ( [[#Bukvareva--2016|Bukvareva and Zamolodchikov, 2016]] ; [[#Yousefpour--2018|Yousefpour et al., 2018]] ). Effects of warming and increasing droughts on soil moisture, respiration and carbon sequestration have been detected across European regions ( ''high confidence'' ) (Figure 13.8; [[#Sanginés%20de%20Cárcer--2018|Sanginés de Cárcer et al., 2018]] ; [[#Carnicer--2019|Carnicer et al., 2019]] ; [[#Green--2019|Green et al., 2019]] ; [[#Schuldt--2020|Schuldt et al., 2020]] ). Forest expansion in boreal regions results in net warming ( [[#Bright--2017|Bright et al., 2017]] ), possibly influencing cloud formation and rainfall patterns ( ''medium confidence'' ) ( [[#Teuling--2017|Teuling et al., 2017]] ). These changes are affecting climate, pollination and soil protection services (Figure 13.8; [[#Verhagen--2018|Verhagen et al., 2018]] ). If not managed through increased reforestation and/or revegetation or peatland restoration, future climate-change impacts will progressively limit the climate regulation capacity of European terrestrial ecosystems ( ''medium confidence'' ) (Figure 13.8), especially in SEU ( [[#Peñuelas--2018|Peñuelas et al., 2018]] ; [[#Xu--2019|Xu et al., 2019]] ). Predominantly positive CO 2 fertilisation effects at current warming will change into increasingly negative effects of warming and drought on forests at higher temperatures ( ''medium confidence'' ) ( [[#Peñuelas--2017|Peñuelas et al., 2017]] ; [[#Green--2019|Green et al., 2019]] ; [[#Ito--2020|Ito et al., 2020]] ; Wang 2020; [[#Yu--2021|Yu et al., 2021]] ). In NEU and EEU, peatlands are projected to shrink with 1.7°C GWL, and become carbon sources at 3°C GWL ( [[#Qiu--2020|Qiu et al., 2020]] ), peat bogs to lose 50% carbon at 2°C GWL, and blanket peatland to shrink or regionally disappear ( [[#Gallego-Sala--2010|Gallego-Sala et al., 2010]] ; [[#Ferretto--2019|Ferretto et al., 2019]] ).

Declines in pollinator ranges in response to climate change are occurring for many groups in Europe ( ''high confidence'' ) (Figure Box 13.1.1; Figure 13.8; [[#Kerr--2015|Kerr et al., 2015]] ; [[#Soroye--2020|Soroye et al., 2020]] ; [[#Zattara--2020|Zattara and Aizen, 2020]] ), with observed shifts to higher elevations in southern and lower elevation in northern species ( [[#Kerr--2015|Kerr et al., 2015]] ) resulting in higher pollinator richness in NEU ( [[#Franzén--2012|Franzén and Öckinger, 2012]] ). Lags in responses to climate change suggest that current impacts on pollination have not been fully realised ( [[#IPBES--2018|IPBES, 2018]] ). Pollinators are also declining due to lack of suitable habitat, pollution, pesticides, pathogens and competing invasive alien species ( [[#Settele--2016|Settele et al., 2016]] ; [[#Steele--2019|Steele et al., 2019]] ).

Projected climate impacts on pollinators show mixed responses across Europe but are greater under 3°C GWL ( ''medium confidence'' ) ( [[#Rasmont--2015|Rasmont et al., 2015]] ). Increasing homogenisation of populations may increase vulnerability to extreme events ( [[#Vasiliev--2021|Vasiliev and Greenwood, 2021]] ). Geographical changes to the climatic niche of pollinators are similar to those of insects, with mixed trends, depending on group and location (Figure 13.9; [[#Kaloveloni--2015|Kaloveloni et al., 2015]] ; [[#Rasmont--2015|Rasmont et al., 2015]] ; [[#Radenković--2017|Radenković et al., 2017]] ). In NEU, species richness may increase for some groups ( [[#Rasmont--2015|Rasmont et al., 2015]] ), with unclear trends for bumblebees ( [[#Fourcade--2019|Fourcade et al., 2019]] ; [[#Soroye--2020|Soroye et al., 2020]] ). Future land use will have important effects on pollinator distribution (Marshall, 2018) as habitat fragmentation in densely populated Europe decreases opportunities for range shifts and microclimatic buffering ( [[#Vasiliev--2021|Vasiliev and Greenwood, 2021]] ).

Soil erosion varies across Europe, with higher rates in parts of SEU and WCE, but lower rates in NEU ( ''high confidence'' ) (Figure 13.8; [[#Petz--2016|Petz et al., 2016]] ; [[#Polce--2016|Polce et al., 2016]] ; [[#Borrelli--2020|Borrelli et al., 2020]] ), related to vegetation type and amount of cover, slope and soil type ( [[#Panagos--2015a|Panagos et al., 2015a]] ). Short-term land-use change and management may impact soil erosion more than climate ( [[#Verhagen--2018|Verhagen et al., 2018]] ). Where conservation agriculture is practised or vegetation cover increasing, erosion is slightly decreasing ( [[#Panagos--2015b|Panagos et al., 2015b]] ; [[#Guerra--2016|Guerra et al., 2016]] ). Reduced soil loss due to reduced spring snowmelt has been observed in EEU ( [[#Golosov--2018|Golosov et al., 2018]] ), while fire exacerbates soil loss especially in SEU ( [[#Borrelli--2016|Borrelli et al., 2016]] ; [[#Borrelli--2017|Borrelli et al., 2017]] ).

Projected increase in rainfall could increase soil erosion, while warming enhances vegetation cover, leading to overall mixed responses ( ''medium confidence'' ) ( [[#Berberoglu--2020|Berberoglu et al., 2020]] ; [[#Ciampalini--2020|Ciampalini et al., 2020]] ). In Europe, rainfall erosion could increase by &gt;81% ( [[#Panagos--2017|Panagos et al., 2017]] ) at 2°C GWL, especially in NEU ( [[#Borrelli--2020|Borrelli et al., 2020]] ) where risks can be limited by soil erosion control ( [[#Polce--2016|Polce et al., 2016]] ). Decreased rainfall projected for parts of SEU could reduce erosion, although increases in rainfall intensity could offset this ( [[#Serpa--2015|Serpa et al., 2015]] ). Soil losses from fire will increase in SEU in response to 2°C GWL ( [[#Pastor--2019|Pastor et al., 2019]] ), especially if combined with extreme rainfall ( [[#Morán-Ordóñez--2020|Morán-Ordóñez et al., 2020]] ). In northern regions, reduced soil losses are projected during spring snowmelt ( [[#Svetlitchnyi--2020|Svetlitchnyi, 2020]] ).

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