Spatial and Temporal Variation in Primary Forest Growth in the Northern Daxing’an Mountains Based on Tree-Ring and NDVI Data

Spatial and Temporal Variation in Primary Forest Growth in the Northern Daxing’an Mountains Based on Tree-Ring and NDVI Data

The results of spatial analyses indicate that in addition to the effect of large-scale climate change on tree growth, microclimatic differences at microtopographical scales can affect spatial variation in tree growth [24,28,29]. The results of this study revealed differences in the growth decline of both P. sylvestris var. mongolica and L. gmelinii at different elevations. The results of the spatial analysis showed that elevation had the greatest relative effect on forest degradation. The intensity of the decline in both species increased with elevation within the same periods. This might stem from the fact that temperature plays a major role in affecting the total growth rate early and late in the growing season [67]. As the temperature decreases with altitude, the growth period of trees starts later, and the growth rate decreases when the growing season is shorter [27]. That is, global warming has not altered changes in P. sylvestris var. mongolica growth with elevation. Although cold temperature limitations at higher elevations may have been mitigated, poorer soil nutrient and moisture conditions will still limit tree growth. The radial growth of P. sylvestris var. mongolica became more strongly correlated with the vegetation index as elevation increased. Therefore, spatial analyses can be conducted on the radial growth of P. sylvestris var. mongolica at high altitudes. Patterns in the radial growth in L. gmelinii at different elevations were consistent with those of P. sylvestris var. mongolica. However, this trend was not observed in the performance of the mid-elevation L. gmelinii sample site (LG-B), which was less correlated with the vegetation index. This stems from the fact that the trees in the LG-B sample site are much older, especially at high altitude; these trees are thus more susceptible to environmental stresses and have lower cambium activity compared with younger trees, which are prone to having narrow or missing tree rings [34]. Topography and slope orientation affect the distribution of water, nutrients, and heat in the region. Southward-facing sunny slopes experience higher intensities of solar radiation and more sunshine hours. This leads to high evapotranspiration and greater soil weathering, which leaves the soil devoid of organic matter and susceptible to moisture limitation [29]. P. sylvestris var. mongolica and L. gmelinii are shade-tolerant and moisture-loving species [68], and south-facing slopes are likely to exacerbate the adverse effects of drought. The relative effect of slope is 7.08%. Soils on steep slopes are more susceptible to erosion and water loss, and this results in a low nutrient content and water deficits [29]. This is similar to the effects of elevation and slope orientation on growth observed in other studies of tree rings. For example, Kermavnar et al. [25] conducted isotopic studies of Fagus sylvatica and found that trees growing on southwestern slopes experienced greater environmental stress compared with trees on slopes with different orientations, and this was attributed to differences in the strength of water evapotranspiration on slopes of different orientations. Kooch et al. [69] explored the effects of soil conditions and altitude on silvicultural systems, and high altitude had an adverse effect on soil function and fertility. Overall, topography affects the distribution of environmental factors, and the responses of trees to environmental factors vary among regions. Thus, the climatic environment of the region has a strong effect on the topographic patterns of recession. Climatic and environmental factors require consideration when analyzing the effects of topographic factors on tree growth.

Disasters Expo USA, is proud to be supported by Inergency for their next upcoming edition on March 6th & 7th 2024!

The leading event mitigating the world’s most costly disasters is returning to the Miami Beach

Convention Center and we want you to join us at the industry’s central platform for emergency management professionals.
Disasters Expo USA is proud to provide a central platform for the industry to connect and
engage with the industry’s leading professionals to better prepare, protect, prevent, respond
and recover from the disasters of today.
Hosting a dedicated platform for the convergence of disaster risk reduction, the keynote line up for Disasters Expo USA 2024 will provide an insight into successful case studies and
programs to accurately prepare for disasters. Featuring sessions from the likes of The Federal Emergency Management Agency,
NASA, The National Aeronautics and Space Administration, NOAA, The National Oceanic and Atmospheric Administration, TSA and several more this event is certainly providing you with the knowledge
required to prepare, respond and recover to disasters.
With over 50 hours worth of unmissable content, exciting new features such as their Disaster
Resilience Roundtable, Emergency Response Live, an Immersive Hurricane Simulation and
much more over just two days, you are guaranteed to gain an all-encompassing insight into
the industry to tackle the challenges of disasters.
By uniting global disaster risk management experts, well experienced emergency
responders and the leading innovators from the world, the event is the hub of the solutions
that provide attendees with tools that they can use to protect the communities and mitigate
the damage from disasters.
Tickets for the event are $119, but we have been given the promo code: HUGI100 that will
enable you to attend the event for FREE!

So don’t miss out and register today:

And in case you missed it, here is our ultimate road trip playlist is the perfect mix of podcasts, and hidden gems that will keep you energized for the entire journey


This website uses cookies to improve your experience. We'll assume you're ok with this, but you can opt-out if you wish. Accept Read More