Deep Ecology, Biodiversity and Assisted Natural Regeneration of European Hemiboreal Forests

Abstract

Climate change and the associated disturbances have disrupted the relative stability of tree species composition in hemiboreal forests. The natural ecology of forest communities, including species occurrence and composition, forest structure, and food webs, have been affected. Yet, the hemiboreal forest zone of Lithuania is the least studied in the country for climate change risks and possible management adaption techniques. This problem is further complicated by the fact that Lithuania uses a traditional centralised forest management system. Therefore, this work proposes assisted natural regeneration (ANR) of tree species as a more viable means of building hemiboreal forest resilience to cope with future climate change risks. The ANR model implies that forest management is localised in local communities, to provide opportunities for the local people to participate in forest management based on local knowledge, thereby facilitating the transition from cultural diversity to biodiversity. Further, ANR is grounded on an ethical framework—deep ecology—to provide ethical justification for the proposal to transit forest management in Lithuania from the traditional centralised segregated system to a community-driven practice. The work combines the theories of ANR, deep ecology, and hemiboreal forest knowledge systems to provide complementary information that builds on gaps in the existing literature. This study is unique in that no previous work has linked ANR and deep ecology in the context of Lithuania’s forest ecosystems.

Adaptive Relationships in Hemi-Boreal Forests: Tree Species Responses to Competition, Stress, and Disturbance

“…Stress-resistant ruderals emerge as gap makers and grow only in forest sites that have been completely disturbed and damaged [ 58 ]. Their juveniles have the highest growth potential and colonize into large gaps (frequently with exposed mineral soils) after their formation and grow only in them as dominants [ 36 , 59 ]. Eurasian aspen, silver birch and Scots pine are characterized by a high light demand and low shade tolerance; the undergrowth of these species is absent under the dense canopy [ 60 ].…”

“…Competitive stress-sensitive ruderals emerge as gap fillers [ 59 ] with their seeds germinating better in light gaps with medium canopy openness than in the understory or large gaps, and saplings can survive in closed forests [ 36 , 60 ]. In the stages from juveniles to adolescence, Norway maple, wych elm, and Norway spruce are characterized by a considerable shade tolerance and a high light demand.…”

“…Ruderal stress-sensitive competitors emerge as gap successors with advance regeneration [ 58 , 59 ]. Their already established juveniles survive in newly created light gaps [ 36 ]. European ash and English oak are very shade-tolerant in their juvenile stage, but at subsequent stages of ontogeny, their need for light increases sharply; both species use full light, and their significant productivity is a result of high photosynthesis rates [ 60 ].…”

“…Stress-resistant competitors regenerate before gap formation in the shade as gap advancers; juveniles have average growth rates [ 36 , 59 ]. Small-leaved lime is comparable to Norway spruce and European hornbeam in the juvenile stage in terms of the light minimum, but in the generative stage it has similar light demands as European aspen and European ash [ 60 ].…”

“…Adhering to previous research on European and Lithuanian forest types [ 23 , 28 , 31 ], we classified the tree species of each typical forest vegetation community according to four adaptive strategy types of tree establishment and phenological development in the forest. The classification is based on the characteristics of major soil groups determined according to the World Reference Base for Soil Resources [ 32 , 33 , 34 , 35 ], potential natural vegetation [ 23 , 28 ], and forest disturbance regimes [ 5 , 36 ].…”