Differential age and species growth responses to climate warming detected in old-growth Mediterranean mountain forests 

2021 ◽  
Author(s):  
Michele Colangelo ◽  
Jesus Julio Camarero ◽  
Antonio Gazol ◽  
Marco Borghetti ◽  
Michele Baliva ◽  
...  
Keyword(s):  
Climate Sensitivity ◽  
Growth Rates ◽  
Environmental Conditions ◽  
Abies Alba ◽  
Growth Responses ◽  
Old Growth ◽  
Lower Elevation ◽  
Old Growth Forests ◽  
Old Trees ◽  
The Impact

<p>Mediterranean mountainous forest ecosystems are key hotspots to study the impact of climate change, thus understanding the species-specific growth response is of great relevance. In this study, we take advantage of the few remnant patches of old-growth forests located in the Pollino Massif (southern Italy), to evaluate how the growth of conspecific young and old trees responded to climate. Indeed, thanks to their remote critical topographic conditions in which these patches are located, they have remained nearly untouched from human pressure over the last centuries. We compared two conifer species (Abies alba, Pinus heldreichii var. leucodermis) vs. two hardwood species (Fagus sylvatica, Quercus cerris) in four stands situated along an altitudinal gradient. Younger trees grew faster than their conspecific oldest trees during their juvenile stage, regardless of the environmental conditions and species studied, highlighting more favorable recent climatic and environmental conditions for growth compared to the past. Rising temperature had a positive effect on growth rate in high-elevation young and old P. leucodermis individuals. However, F. sylvatica, inhabiting mesic sites at lower elevation, had slow growth with the least difference in growth rates between young and old trees. Similarly, the growth rates of old tree species found at lower elevation (Q. cerris and A. alba, respectively) tended to be relatively stable since 1950, except for A. alba, increased over the last two decades. Climate sensitivity in recent decades differed between young and old trees in some of the species, with younger trees tending to be more sensitive in Pinus and Abies, and older trees being more sensitive in Fagus. Such disparity in climate sensitivity and long-term growth reactions to climate should be recognized and considered when forecasting the future dynamics of old-growth forests.</p>

scholarly journals Compared to Wildfire, Management Practices Reduced Old-Growth Forest Diversity and Functionality in Primary Boreal Landscapes of Eastern Canada

2021 ◽  
Vol 4 ◽  
Author(s):  
Maxence Martin ◽  
Pierre Grondin ◽  
Marie-Claude Lambert ◽  
Yves Bergeron ◽  
Hubert Morin
Keyword(s):  
Boreal Forests ◽  
Economic Value ◽  
Industrial Scale ◽  
Old Growth ◽  
Ecosystem Based Management ◽  
Old Growth Forest ◽  
Old Growth Forests ◽  
Boreal Landscapes ◽  
The Impact ◽  
Primary Forests

Large primary forest residuals can still be found in boreal landscapes. Their areas are however shrinking rapidly due to anthropogenic activities, in particular industrial-scale forestry. The impacts of logging activities on primary boreal forests may also strongly differ from those of wildfires, the dominant stand-replacing natural disturbance in these forests. Since industrial-scale forestry is driven by economic motives, there is a risk that stands of higher economic value will be primarily harvested, thus threatening habitats, and functions related to these forests. Hence, the objective of this study was to identify the main attributes differentiating burned and logged stands prior to disturbance in boreal forests. The study territory lies in the coniferous and closed-canopy boreal forest in Québec, Canada, where industrial-scale logging and wildfire are the two main stand-replacing disturbances. Based on Québec government inventories of primary forests, we identified 427 transects containing about 5.5 circular field plots/transect that were burned or logged shortly after being surveyed, between 1985 and 2016. Comparative analysis of the main structural and environmental attributes of these transects highlighted the strong divergence in the impact of fire and harvesting on primary boreal forests. Overall, logging activities mainly harvested forests with the highest economic value, while most burned stands were low to moderately productive or recently disturbed. These results raise concerns about the resistance and resilience of remnant primary forests within managed areas, particularly in a context of disturbance amplification due to climate change. Moreover, the majority of the stands studied were old-growth forests, characterized by a high ecological value but also highly threatened by anthropogenic disturbances. A loss in the diversity and functionality of primary forests, and particularly the old-growth forests, therefore adds to the current issues related to these ecosystems. Since 2013, the study area is under ecosystem-based management, which implies that there have been marked changes in forestry practices. Complementary research will be necessary to assess the capacity of ecosystem-based management to address the challenges identified in our study.

scholarly journals Old growth forests and large old trees as critical organisms connecting ecosystems and human health. A review

2022 ◽  
Author(s):  
Melinda Gilhen-Baker ◽  
Valentina Roviello ◽  
Diana Beresford-Kroeger ◽  
Giovanni N. Roviello
Keyword(s):  
Therapeutic Potential ◽  
Root Systems ◽  
Tree Regeneration ◽  
Old Growth ◽  
Old Growth Forests ◽  
Ground Conditions ◽  
Below Ground ◽  
Young Forests ◽  
Old Trees ◽  
Life On Earth

AbstractOld forests containing ancient trees are essential ecosystems for life on earth. Mechanisms that happen both deep in the root systems and in the highest canopies ensure the viability of our planet. Old forests fix large quantities of atmospheric CO2, produce oxygen, create micro-climates and irreplaceable habitats, in sharp contrast to young forests and monoculture forests. The current intense logging activities induce rapid, adverse effects on our ecosystems and climate. Here we review large old trees with a focus on ecosystem preservation, climate issues, and therapeutic potential. We found that old forests continue to sequester carbon and fix nitrogen. Old trees control below-ground conditions that are essential for tree regeneration. Old forests create micro-climates that slow global warming and are irreplaceable habitats for many endangered species. Old trees produce phytochemicals with many biomedical properties. Old trees also host particular fungi with untapped medicinal potential, including the Agarikon, Fomitopsis officinalis, which is currently being tested against the coronavirus disease 2019 (COVID-19). Large old trees are an important part of our combined cultural heritage, providing people with aesthetic, symbolic, religious, and historical cues. Bringing their numerous environmental, oceanic, ecological, therapeutic, and socio-cultural benefits to the fore, and learning to appreciate old trees in a holistic manner could contribute to halting the worldwide decline of old-growth forests.

scholarly journals Post-glacial re-colonization and natural selection have shaped growth responses of silver fir across Europe

2021 ◽  
Author(s):  
Elisabet Martínez-Sancho ◽  
Christian Rellstab ◽  
Frédéric Guillaume ◽  
Christof Bigler ◽  
Patrick Fonti ◽  
...  
Keyword(s):  
Natural Selection ◽  
Ring Width ◽  
Abies Alba ◽  
Least Square ◽  
Extreme Drought ◽  
Silver Fir ◽  
Severe Drought ◽  
Growth Responses ◽  
Bioclimatic Variables ◽  
The Impact

<p>Warmer climate and more frequent extreme droughts will pose major threats to forest ecosystems. Persistence of intra-specific populations of tree species will depend on their tolerance and adaptive capacities to forthcoming climate conditions. However, past demography processes due to post-glacial recolonization can also contribute to the genetic-based differences in growth responses among provenances. In this study, we investigated the impact of climatic conditions on growth traits among 18 provenances of silver fir (<em>Abies alba </em>Mill.) from west, south and eastern Europe growing in two provenance trials established in Switzerland in 1980s. We further assessed whether the differences in growth-related traits across provenances were linked to their genetic differences due to recolonization history and natural selection processes.</p><p>In total 250 individuals were measured and cored for dendrochronological analyses, and different growth-related traits were calculated: i) total tree height and diameter at breast height (DBH), ii) growth-climate relationships using correlations between tree-ring width and monthly climate parameters as well as levels of autocorrelation, and iii) short-term responses to extreme drought using resilience components (resilience, resistance, and recovery) to the severe drought that occurred in the study area in 2003. We also genotyped all the individuals in 150 putatively neutral single nucleotide polymorphisms to define the neutral genetic structure of the population, the neutral genetic differentiation among provenances (<em>F<sub>ST</sub></em>) and the genetic variation among provenances in relation to the total genetic variance in a trait (<em>Q<sub>ST</sub></em>). Signs of natural selection were assessed by two approaches: i) Pearson correlations between the least-square means of provenances of the traits and bioclimatic variables from the seed origin, and ii) <em>Q<sub>ST</sub>-F<sub>ST</sub></em> comparison.</p><p>The studied provenances grouped into three longitudinal clusters reassembling the genetic lineages of refugia from the last glacial maximum: the provenance of the Pyrenees as a sole member of the westernmost cluster, the Central European provenances representing the central cluster and all the eastern European provenances forming the eastern cluster. These three lineages showed differences in growth performance traits (height and DBH), with the trees from the eastern cluster being the top performers. The Pyrenees cluster showed significantly lower recovery and resilience to the extreme drought of 2003 as well as lower values of growth autocorrelation. A <em>Q<sub>ST</sub>-F<sub>ST</sub></em> and correlation analyses with climate of provenance origin suggest that the differences among provenances found in some traits result from natural selection. Our study suggests that post-glacial re-colonization and natural selection are the major drivers explaining the intra-specific variability in growth of silver fir across Europe. These findings provide insights to support assisted gene flow to ensure the persistence of the species in European forests.</p>

Tree growth and mortality after small-group harvesting in New Zealand old-growth Nothofagus forests

2005 ◽  
Vol 35 (10) ◽  
pp. 2323-2331 ◽  
Author(s):  
Susan K Wiser ◽  
Robert B Allen ◽  
Udo Benecke ◽  
Gordon Baker ◽  
Duane Peltzer
Keyword(s):  
New Zealand ◽  
Tree Growth ◽  
Growth Models ◽  
Forest Growth ◽  
Major Influence ◽  
Growth Responses ◽  
Old Growth ◽  
Diameter Increment ◽  
Large Trees ◽  
The Impact

In New Zealand uncertainty about how silvicultural systems influence growth and mortality of residual beech trees has caused controversy surrounding sustainable beech management. We assess the impact of group-selection harvesting on residual-tree growth and mortality in old-growth hard beech (Nothofagus truncata (Col.) Ckn.) and mixed red beech – silver beech (Nothofagus fusca (Hook. F.) Oerst. – Nothofagus menziesii (Hook. F.) Oerst.) forests. Proximity to cuts had a major influence on growth that varied with both species and initial tree diameter. For all three beech species, diameter increment of small trees (<60 cm DBH) in intact forest was less than that of large trees, but smaller trees grew two- to four-fold faster along cut edges than in intact forest. In contrast, growth of large hard beech and silver beech and intermediate-sized red beech trees did not vary with cut proximity, suggesting that these main canopy trees were growing at a maximum potential rate. Edge trees were more likely to die as their level of Platypus beetle infection increased, but overall mortality rates were unrelated to harvest proximity. These results demonstrate that complex mortality and growth responses to harvesting should be incorporated into forest growth models upon which silvicultural systems that sustain the structural, compositional, and functional characteristics of forests are based.

Patterns between crown characteristics and radial increment in trees are similar during recovery and normal growth: a long-term example from old-growth forests

2019 ◽  
Vol 49 (9) ◽  
pp. 1069-1077
Author(s):  
Rafał Podlaski
Keyword(s):  
Tree Growth ◽  
Abies Alba ◽  
Normal Growth ◽  
Additive Models ◽  
Silver Fir ◽  
Radial Increment ◽  
Prediction Errors ◽  
Old Growth ◽  
Old Growth Forests ◽  
Crown Characteristics

Crown traits and competition attributes have an important effect on tree radial increment. Relationships among these elements are modeled using the distributions of the crown characteristics in a given calendar year, but these patterns can differ over time. The suitability of the patterns during recovery and normal growth was investigated using silver fir, Abies alba Mill., in old-growth forests. Generalized additive models (GAMs) for silver fir in the older (OG, trees aged 136–300 years) and younger (YG, trees aged 45–135 years) generations were developed. To test the validity of these GAMs, field data sets representing silver fir recovery and normal growth were used. For silver fir in OG, crown transparency had the largest effect on tree growth, explaining more than 25% of the variance. For silver fir in YG, relative crown length had the largest effect on tree growth, explaining more than 15% of the variance. The absolute relative prediction errors, AREmin and AREmax, were less than 0.03 and 1.50 mm, respectively. The developed GAMs are suitable during recovery and normal growth, but the GAMs were fitted to a relatively small area, neglecting climatic gradients and different disturbance types. This type of investigation should be continued on a larger scale.

scholarly journals Occurrence of Psocoptera in boreal old-growth forests

2007 ◽  
Vol 18 (3) ◽  
Author(s):  
Jussi Kanervo ◽  
Gergely Várkonyi
Keyword(s):  
19Th Century ◽  
Host Tree ◽  
Distribution Data ◽  
Forest Biodiversity ◽  
Old Growth ◽  
Old Growth Forest ◽  
Old Growth Forests ◽  
Old Trees ◽  
The 19Th Century ◽  
New Distribution

We aim to assess habitat and host-tree preferences of psocids (Insecta: Psocoptera) sampled in old-growth-forest biodiversity studies conducted during 1997–2003 in central and southern Finland. Thirty-one out of the recognized sixty-nine Finnish species were found in the samples, four of which (Elipsocus abdominalis, Reuterella helvimacula, Stenopsocus lachlani and Trichadenotecnum majus) might be associated with old-growth forests or with old trees. Psocidus flavonimbatus, a rare taiga species only previously known from the 19th century holotype from Estonia, was repeatedly collected in Kuhmo region, eastern Central Finland. This species is possibly associated with boreal spruce-dominated old-growth forests and likely to prefer Norway spruce as a host tree. We also provide new distribution data for several species and discuss their host-tree preferences.

scholarly journals Impact of rising temperatures on the biomass of humid old-growth forests of the world

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Markku Larjavaara ◽  
Xiancheng Lu ◽  
Xia Chen ◽  
Mikko Vastaranta
Keyword(s):  
Air Temperature ◽  
Carbon Dioxide Concentration ◽  
Temperature Response ◽  
Above Ground Biomass ◽  
Old Growth ◽  
Ground Biomass ◽  
The World ◽  
Old Growth Forests ◽  
Fertilization Effects ◽  
The Impact

Abstract Background Understanding how warming influence above-ground biomass in the world’s forests is necessary for quantifying future global carbon budgets. A climate-driven decrease in future carbon stocks could dangerously strengthen climate change. Empirical methods for studying the temperature response of forests have important limitations, and modelling is needed to provide another perspective. Here we evaluate the impact of rising air temperature on the future above-ground biomass of old-growth forests using a model that explains well the observed current variation in the above-ground biomass over the humid lowland areas of the world based on monthly air temperature. Results Applying this model to the monthly air temperature data for 1970–2000 and monthly air temperature projections for 2081–2100, we found that the above-ground biomass of old-growth forests is expected to decrease everywhere in the humid lowland areas except boreal regions. The temperature-driven decrease is estimated at 41% in the tropics and at 29% globally. Conclusions Our findings suggest that rising temperatures impact the above-ground biomass of old-growth forests dramatically. However, this impact could be mitigated by fertilization effects of increasing carbon dioxide concentration in the atmosphere and nitrogen deposition.

Interacting effects of behavior and oceanography on growth in salmonids with examples for coho salmon (Oncorhynchus kisutch)

2005 ◽  
Vol 62 (6) ◽  
pp. 1219-1230 ◽  
Author(s):  
Melissa L Snover ◽  
George M Watters ◽  
Marc Mangel
Keyword(s):  
Growth Model ◽  
Growth Rates ◽  
Environmental Conditions ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Resource Acquisition ◽  
Environment Interaction ◽  
Aggressive Behaviors ◽  
Growth Responses ◽  
Negative Relationships

Positive and negative relationships between pre- and post-smolt growth rates in salmonids have been observed, but the mechanisms underlying these relationships are not understood. We hypothesize that growth at sea is controlled by interactions between behavior and ocean conditions and that no one relationship is correct. We present a growth model with habitat-specific rates of anabolism that allow resource acquisition to vary in response to the behavior–environment interaction. Our model predicts positive relationships between pre- and post-smolt growth rates when ocean resources have clumped, defensible distributions under which conditions that aggressive behaviors facilitate increased access to those resources. Negative relationships are predicted when resources are dispersed and aggressive behaviors are ineffective. We present data relating pre- and post-smolt growth rates for more than 15 stocks of coho salmon (Oncorhynchus kisutch). These data indicate that shortly after out-migrating, aggressive behaviors are not effective for securing resources in the ocean (i.e., there are negative or no relationships between pre- and post-smolt growth rates). As coho spend more time at sea, however, variability in environmental conditions can elicit a variety of growth responses.

Growth responses to climate and drought in silver fir (Abies alba) along an altitudinal gradient in southern Kosovo

2011 ◽  
Vol 41 (9) ◽  
pp. 1795-1807 ◽  
Author(s):  
Elvin Toromani ◽  
Mitat Sanxhaku ◽  
Edmond Pasho
Keyword(s):  
Radial Growth ◽  
Ring Width ◽  
Abies Alba ◽  
High Elevation ◽  
Negative Influence ◽  
Drought Indices ◽  
Silver Fir ◽  
Growth Responses ◽  
Spring Temperatures ◽  
The Impact

This paper deals with the response of silver fir ( Abies alba Mill.) growth to climate, mainly drought, presenting data from southern Kosovo, for which only little information is available. Two cores from 55 dominant trees were extracted at two sites representing the limits of the natural distribution of silver fir. We built 80- and 112-year-long chronologies for each site. Comparison of both ring width chronologies showed that they were diverse. Pointer year analysis indicated that high spring temperatures and ample rainfall (1082 mm) influenced positively silver fir growth (wide ring), while low spring temperatures and scarce precipitation had an inverse effect. Bootstrapped response functions confirmed that April and May temperatures of the current growth year influenced positively silver fir growth at the low-elevation site, while the July precipitation of the previous growth year had a negative influence. At the high-elevation site, warm previous December temperatures had a positive influence on silver fir growth. Drought indices indicated two periods (1953–1961 and 1994–2001) with moderate drought. Correlation analysis between silver fir radial growth and drought indices revealed that the impact of drought on radial growth was significant at the time scale of 1.5 months during the summer months.

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