Does a whole plant conservation gradient exist within a subtropical broadleaved evergreen forest?

The coordination between leaf and root traits is crucial for plants to synchronize their strategies for acquiring and utilizing above- and belowground resources. Nevertheless, the generality of a whole plant conservation gradient is still controversial. Such testing has been conducted mainly among communities at large spatial scales, and thus evidence is lacking within communities.

Primary productivity regulates rhizosphere soil organic carbon: Evidence from a chronosequence of subtropical Chinese fir (Cunninghamia lanceolata) plantation.

Tree plantations worldwide are a large terrestrial carbon sink. Previous studies on the carbon sequestration capacity of plantations mainly focused on tree biomass carbon sequestration, but the importance of soil organic carbon (SOC) was relatively unclear. Living root carbon inputs influence SOC via plant-microbe interactions in the rhizosphere and play an essential role in nutrient cycling.

[Seasonal dynamics in photosynthetic characteristics and growth of saplings and their response to soil warming].

In order to understand the response and adaptation mechanisms of photosynthetic characteristics and growth for saplings in the subtropical region to global warming, we conducted the root-box warming experiment (ambient, ambient+4 ℃) at the Sanming Forest Ecosystem National Observation and Research Station in Fujian Province to investigate the effects of soil warming on the photosynthetic characteristics and growth of saplings in different seasons. The results showed that the net photosynthetic rate () and stomatal conductance () of significantly decreased in summer compared with in spring and autumn. Soil warming had no effect on the and of .

[Effect of environmental factors on mineral soil respiration: A review].

Mineral soil respiration, a major component of CO emissions from soil to atmosphere, plays a critical role in driving terrestrial ecosystem carbon cycling and is highly sensitive to environmental changes, including soil temperature, soil moisture, and substrate availability. The changes of environmental factors can affect mineral soil respiration and its temperature sensitivity thereby alters global carbon balance. We reviewed studies on the effects of environmental factors on mineral soil respiration and its temperature sensitivity.

Effects of warming on fine root lifespan of forests: A review.

As an important parameter of forests growth, fine root lifespan plays an important role in plant water and nutrient absorption, and affects underground distribution of photosynthetic products and forest ecosystem carbon cycling. The impact of climate warming on fine root lifespan has become a hot issue under the context of global change. The responses of fine root lifespan to global warming will affect ecosystem carbon balance.

Substrate and adenylate limit subtropical tree fine-root respiration under soil warming.

How root respiration acclimates to global warming remains unclear, especially in subtropical forests that play a key role in the global carbon budget. In a large-scale in situ soil warming experiment, the occurrence of, and mechanisms controlling over, the acclimation of fine-root respiration of Cunninghamia lanceolata during the fourth year of warming were investigated. Specific respiration rates (at reference temperature of 20°C; SRR ) were measured with exogenous glucose addition, uncoupler addition, or no addition, and root morphological and chemical traits were also measured.

Soil warming decreased dissolved organic carbon quantity and quality in subtropical forests.

Soil dissolved organic carbon (DOC) is the most active part in forest soil carbon pool, the responses of which to climate warming has profound effects on forest carbon cycling. Based on a manipulative soil warming experiment in subtropical evergreen broad-leaved forests, we collected soil solutions and used ultraviolet-visible, infrared and three-dimensional fluorescence spectroscopy analyses to explore the effects of soil warming (+4 ℃, 1 year) on soil DOC quantity and quality along the soil profile. The results showed that soil DOC flux remained constant along the soil profile.

Effects of warming on quantity and structure of litter-derived dissolved organic matter in subtropical natural forests.

Litter-derived dissolved organic matter (DOM) is an important source of soil DOM, and the response of which to climate warming may change forest soil carbon and nitrogen dynamics, such as soil carbon and nitrogen mineralization. In this study, we conducted a field manipulative warming experiment in natural forests. Combined with litter leaching solution collected in the field and ultraviolet-visible and three-dimensional fluorescence spectroscopy analyses, we explored the effects of warming on the content and structure of litter-derived DOM in subtropical evergreen broad-leaved forests.

Root nitrogen uptake capacity of Chinese fir enhanced by warming and nitrogen addition.

There is a knowledge gap in the effects of climate warming and nitrogen (N) deposition on root N absorption capacity, which limits our ability to predict how climate change alters the N cycling and its consequences for forest productivity especially in subtropical areas where soil N availability is already high. In order to explore the effects and mechanism of warming and the N deposition on root N absorption capacity of Chinese fir (Cunninghamia lanceolata), a subtropical arbuscular mycorrhizal conifer, the fine root 15NH4+ and 15NO3- uptake kinetics at a reference temperature of 20 °C were measured across different seasons in a factorial soil warming (ambient, +5 °C) × N addition (ambient, +40 kg N ha-1 yr-1) experiment. The results showed that (i) compared with the control, warming increased the maximal uptake rate of NH4+ (Vmax,20 °C-NH4+) in summer, while N addition enhanced it in spring and summer; compared with non-warming treatments, warming treatments increased the uptake rate of NO3- at a reference concentration of 100 μmol (V100,20 °C-NO3-) in spring.

[Effects of management on the content and spectral characteristics of soil dissolved organic carbon in a subtropical forest].

The differences of artificial measures, such as logging residue management, between assisted natural regeneration and afforestation may change the content and structure of soil dissolved organic carbon (DOC) and affect forest carbon cycle. In this study, we investigated the effects of managements on the content and spectral characteristics of DOC in a subtropical forest, which contained the forest of assisted natural regeneration (Ⅱ), and the plantation (Ⅲ), both were converted from mature secondary forests (Ⅰ). Results showed that DOC content in the 0-10 cm soil layer was significantly decreased by 21% and 50% in Ⅱ and Ⅲ, respectively, compared with that in Ⅰ.

Analysis and Prediction of Influence Factors of Green Computing on Carbon Cycle Process in Smart City.

Global warming has become the focus of attention of the international community, and the control of carbon dioxide emissions has become one of the necessary choices for the development strategies of countries around the world. Cities are places where carbon dioxide emissions are concentrated. The key to controlling carbon emissions is to control the carbon emissions of cities.

[Effects of forest conversion on litterfall nutrient return and nutrient use efficiency in Mid-subtropical China.].

To understand the impacts of mid-subtropical forest conversion on carbon and nutrient cycling, we conducted a 4-year investigation to examine litterfall, nutrient return and nutrient use efficiency of natural forest, secondary forest and plantation which were transformed from natural forest. The results showed that after natural forest was transformed into secon-dary forest and plantation, the annual litter production decreased by 29.0% and 45.

Root age-related response of fine root respiration of Chinese fir seedlings to soil warming.

The variation in fine root respiration with root age provides insight into root adaptation to climate warming, but the mechanism is poorly understood. In this study, we investigated the respiratory response of fine roots (<1 mm and 1-2 mm) of different ages (2-, 4- and 6-month old) of Chinese fir (Cunninghamia lanceolata (Lamb.)) seedlings to soil warming (4 °C above the control using cable heating).

Variations in Rainfall Affect the Responses of Foliar Chemical Properties of Seedlings to Soil Warming.

Climate warming is becoming an increasingly serious threat. Understanding plant stoichiometry changes under climate warming is crucial for predicting the effects of future warming on terrestrial ecosystem productivity. Nevertheless, how plant stoichiometry responds to warming when interannual rainfall variation is considered, remains poorly understood.

[Fine root production in initial stage of Castanopsis carlesii under different regeneration modes in Sanming, Fujian Province, China].

Fine root biomass and production in initial stage of three different regeneration approaches, i.e., natural regeneration with anthropogenic promotion (AR) , the Castanopsis carlesii plantation ( CC) and the Cunninghamia lanceolata plantation ( CL) on the clear-cutting sites of the secondary forest of C.

[Effects of tree species diversity on fine-root biomass and morphological characteristics in subtropical Castanopsis carlesii forests].

Fine roots in the Castanopsis carlesii plantation forest (MZ), the secondary forest of C. carlesii through natural regeneration with anthropogenic promotion (AR), and the secondary forest of C. carlesii through natural regeneration (NR) in Sanming City, Fujian Province, were estimated by soil core method to determine the influence of tree species diversity on biomass, vertical distribution and morphological characteristics of fine roots.