Treelines—Approaches at Different Scales

Abstract

Scales in treeline research depend on the objectives and must match the underlying natural processes. Factors and processes at one scale may not be as important at another scale. In the global view, the number of factors influencing climatic treeline position can be reduced to the effects of heat deficiency. Emphasis, however, should be laid on differentiation of the treeline by their regionally and locally varying physiognomy, diversity, spatial and temporal features, and heterogeneity. An assessment of the relative importance of the factors shaping regional/local treeline physiognomy, spatial patterns, and dynamics should have priority. This can be achieved only by syndisciplinary research. Such studies are indispensable for assessing treeline response to climate change at the regional and landscape scales.

Soil Preferences in Germination and Survival of Limber Pine in the Great Basin White Mountains

“…Future treeline is generally expected to shift higher in elevation by as much as 700 m by the year 2100 [9,10], however there is considerable variability in the speed of treeline response to warming in mountains world-wide [11]. This variation is likely due to several mitigating factors including geomorphology, lags in population changes, and dispersal limitations [6,[12][13][14]. Soil type in particular may affect the ability of trees to establish above current treeline.…”

Detecting treeline dynamics in response to climate warming using forest stand maps and Landsat data in a temperate forest

“…The vegetation of treelines and alpine ecotones is among the most vulnerable and sensitive to the impact of global warming on earth (Masek 2001, Bharti et al 2012, Weisberg et al 2013, Gaire et al 2017, Mishra and Mainali 2017. The movement of forest treelines towards higher altitudes is mainly related to thermal variations and other factors (Zinnert et al 2011, Du et al 2017, Gaire et al 2017, Holtmeier and Broll 2017, Skowno et al 2017, such as enhanced atmospheric CO 2 and nitrogen deposition (Masek 2001, Grace et al 2002, Salzer et al 2009, Capers et al 2013, Skowno et al 2017. Simultaneously, increases in these factors usually result in the migration of alpine plants to upper altitudes.…”

“…Holtmeier and Broll 2017 stated, "82% of coarse scale (regional) variation in treeline elevation is associated with thermal conditions". However, there is evidence that accelerated glacier melt in sensitive, snow-covered mountain areas due to increasing temperature impacts treeline structure and composition (MacDonald et al 2008, Capers et al 2013, Wilmers et al 2013, Holtmeier and Broll 2017. However, there are a few studies investigating the case of forest treelines in the Mediterranean region, and there is a gap in knowledge about forest treeline dynamics and structural shifts.…”

Leap frog in slow motion: Divergent responses of tree species and life stages to climatic warming in Great Basin subalpine forests

“…Despite these predictions, there is substantial variability in the speed of treeline response to warming in mountains around the world (Camarero et al, 2017). This variation may be due to many factors, such as varying geomorphology, past human disturbance, lags in population dynamics, dispersal limitation, and biological interactions (competition, herbivory; Grace, Berninger, & Nagy, 2002;Harsch, Hulme, McGlone, & Duncan, 2009;Holtmeier, 2003;Holtmeier & Broll, 2017;Speed, Austrheim, Hester, & Mysterud, 2010). Variability in treeline advance hints that in addition to warming temperature, there are other factors influencing treeline advance, most of which remain unexplored.…”