Evidence for rising upper limits of four native New Zealand forest trees

Abstract

Since the 1860s New Zealand mean air temperatures have risen about 0.5~ which might be expected to have led to a rise of about 100 m in altitudinal limits of plants. Four tree species were examined at several South Island localities for evidence of such a rise.Young silver beech plants have established above the upper limit of mature trees, mostly within the last 60 years. However, as beech timberlines are strongly buffered, few of these young plants occur more than 9 m from the forest margin. Above mountain beech timberlines, which lie in drier climates east of the Main Divide, the "advance zone" is usually less than 7 m wide, and does not include the exposed spurs and northerly faces where timberline ascends highest. Above the limit of mature red beech trees, there is a zone in which younger red beech, up to 150 years old, occur through nearly 30 m of altitude. Scanty data for miro suggest a still wider advance zone.The difference between the potential altitudinal rise of upper limits and that which is actually achieved suggests that in the event of rapid and substantial climatic change, species with intrinsically slow rates of spread would be unable to keep pace. Those with narrow environmental ranges could be Received 20August 1991; accepted 23 July 1992 threatened with extinction unless managed so as to assist dispersal and establishment. B91037To substantiate the prima facie findings of this study, transects have been set up to monitor long term future changes.

The altitude-for-latitude disparity in the range retractions of woody species

“…Contemporary plant range shifts are most frequently reported from mountain regions, with elevational shifts of the mountain treeline being the most commonly documented response to increasing temperatures [8][9][10][11][12]. The distributions of species in mountain regions are typically restricted to relatively narrow and well-delineated altitudinal bands, in comparison with often broad and poorly defined latitudinal distributions in the lowlands.…”

“…Minimum temperatures are particularly important in limiting the poleward (see Glossary) expansion of plant species, whereas limited water availability interacts with high temperatures to exert a direct climatic limitation on their expansion in the opposite, or equatorial, direction in many regions [1][2][3][4][5][6][7]. Changes in climate are, therefore, predicted to alter the geographic distribution of plant species at global to local scales.Contemporary plant range shifts are most frequently reported from mountain regions, with elevational shifts of the mountain treeline being the most commonly documented response to increasing temperatures [8][9][10][11][12]. The distributions of species in mountain regions are typically restricted to relatively narrow and well-delineated altitudinal bands, in comparison with often broad and poorly defined latitudinal distributions in the lowlands.…”

Rapid climate change‐related growth decline at the southern range edge of Fagus sylvatica

“…Although there are now numerous reports of ongoing climate-related range changes of woody species (see e.g. Wardle & Coleman, 1992;Meshinev et al, 2000;Sturm et al, 2001;Kullman, 2002Kullman, , 2003Lloyd & Fastie, 2003;Peñ uelas & Boada, 2003;Sanz-Elorza et al, 2003), these are heavily biased toward the leading edge of the species' distribution. As recruitment is generally more sensitive to climate than mortality, an increase in reproduction at the expanding range edge of a tree species' distribution occurs more rapidly than an increase in the mortality of established trees at the retreating edge (LaMarche, 1973;Lloyd, 1997).…”

The Role of Wood Microsites at Timberline-Alpine Meadow Borders for Conifer Regeneration

“…Although climate warming facilitates seeding regeneration due to factors including increased substrate temperature, increased snow-free period, and increased mean summer temperature (Franklin et al 1971, Peterson 1998, Kullman 2006, Hallinger et al 2010, factors likely to continue limiting regeneration in the ATE include high radiation, frost, drought, animal predation, and infestation by fungal pathogens found in snow and soil (Baig and Tranquillini 1980, Wardle and Coleman 1992, Calloway 1995, Bansal and Germino 2008, Zhong and van der Kamp 1999.…”

“…Microsites may enhance survival and growth of seedlings at the ATE where growth is often limited due to stressful growing conditions including high wind speeds, high radiation, cold air and soil temperatures, soil pathogens, and short growing season due to snow cover (Baig and Tranquillini 1980;Wardle and Coleman 1992, Calloway 1995, Zhong and van der Kamp 1999, Bansal and Germino 2008 (Villalba et al 1994). In Ecuador, lower altitude tree lines on east-facing slopes have been related to radiation received by east-facing slopes in the clear mornings, resulting in photoinhibition of Polylepis seedlings (Cierjacks et al 2007).…”