Precipitation Dominates the Allocation Strategy of Above- and Belowground Biomass in Plants on Macro Scales

Abstract

The allocation of biomass reflects a plant’s resource utilization strategy and is significantly influenced by climatic factors. However, it remains unclear how climate factors affect the aboveground and belowground biomass allocation patterns on macro scales. To address this, a study was conducted using aboveground and belowground biomass data for 486 species across 294 sites in China, investigating the effects of climate change on biomass allocation patterns. The results show that the proportion of belowground biomass in the total biomass (BGBP) or root-to-shoot ratio (R/S) in the northwest region of China is significantly higher than that in the southeast region. Significant differences (p < 0.05) were found in BGBP or R/S among different types of plants (trees, shrubs, and herbs plants), with values for herb plants being significantly higher than shrubs and tree species. On macro scales, precipitation and soil nutrient factors (i.e., soil nitrogen and phosphorus content) are positively correlated with BGBP or R/S, while temperature and functional traits are negatively correlated. Climate factors contribute more to driving plant biomass allocation strategies than soil and functional trait factors. Climate factors determine BGBP by changing other functional traits of plants. However, climate factors influence R/S mainly by affecting the availability of soil nutrients. The results quantify the productivity and carbon sequestration capacity of terrestrial ecosystems and provide important theoretical guidance for the management of forests, shrubs, and herbaceous plants.

Forest Age Drives the Resource Utilization Indicators of Trees in Planted and Natural Forests in China

“…The resource use strategy of natural forests is mainly influenced by climatic and stand factors, whereas that of planted forests is predominantly affected by stand factors ( Figure 8 ). This is because climatic factors (such as temperature, precipitation, and sunlight duration) affect tree SLA and LDMC by influencing photosynthesis intensity, respiration rate, leaf transpiration, and the plant’s ability to absorb nutrients from the soil, thereby affecting the tree’s resource use strategy [ 39 , 40 ]. Stand factors (forest age and density), on the other hand, influence the forest’s resource use strategy by altering the species composition of the forest ecosystem, the response to environmental changes, and the availability of soil nutrients [ 4 , 15 , 41 , 42 ].…”

Elevation Influences Belowground Biomass Proportion in Forests by Affecting Climatic Factors, Soil Nutrients and Key Leaf Traits

“…Increased precipitation generally implies improved soil moisture conditions. Under conditions of ample moisture, plants may not need to develop extensive root systems to acquire water, thus potentially reducing investment in belowground biomass and allocating more resources to the growth of aboveground parts, like leaves and stems [ 57 ]. Forest BGBP significantly increases with longer daylight duration.…”

Climate Factors Influence Above- and Belowground Biomass Allocations in Alpine Meadows and Desert Steppes through Alterations in Soil Nutrient Availability

“…In water-scarce grasslands, plants respond by increasing both horizontal and vertical root growth to access more water resources [ 46 ]. Consequently, they gradually reduce their investment in belowground root construction, leading to a decrease in BGBP [ 47 ]. DSs display higher sensitivity to rainfall changes compared to AMs.…”

“…Desert plants tend to adopt conservative growth strategies that they maintain even when nutrient availability increases, as water often serves as the more critical limiting factor. This strategy reduces their dependence on and sensitivity to nutrient changes [ 47 ]. In contrast, plants in AMs may rely more on soil nutrients due to the need for rapid growth and reproduction within a short growing season, rendering them more sensitive to shifts in the soil nutrient status [ 21 ].…”