How C: N: P stoichiometry in soils and carbon distribution in plants respond to forest age in a Pinus tabuliformis plantation in the mountainous area of eastern Liaoning Province, China

Carbon distribution in plants and ecological stoichiometry in soils are important indicators of element cycling and ecosystem stability. In this study, five forest ages, young forest (YF), middle-aged forest (MAF), near-mature forest (NMF), mature forest (MF), and over-mature forest (OMF) in a Pinus tabuliformis plantation were chosen to illustrate interactions among the C: N: P stoichiometry in soils and carbon distribution in plants, in the mountainous area of eastern Liaoning, China. Carbon content was highest in the leaves of MAF (505.90 g⋅kg−1) and NMF (509.00 g⋅kg−1) and the trunks of YF (503.72 g⋅kg−1), MF (509.73 g⋅kg−1), and OMF (504.90 g⋅kg−1), and was lowest in the branches over the entire life cycle of the aboveground components (335.00 g⋅kg−1). The carbon content of the fine roots decreased with soil layer depth. In YF, MAF, and NMF carbon content of fine roots at 0.5 m was always higher than that of fine roots at 1 m; however, it was the opposite in MF and OMF. The carbon content of the leaves changed with forest age; however, carbon content of branches, trunks and fine roots did not change significantly. Soil total carbon (TC), total nitrogen (TN), total phosphorus (TP), and available phosphorus (AP) content was highest in the OMF. Soil TC, TN and AP content, and TC: TN, TC: TP and TN: TP ratio decreased with increasing soil depth. Soil TC, TN, and TP content had a significant effect on the carbon content of fine roots (p < 0.05). The leaf carbon content and soil element content changed obviously with forest age, and the soil TN, TP and AP increased, which might reduce the carbon content allocation of fine roots.

Response of Leaf Biomass, Leaf and Soil C:N:P Stoichiometry Characteristics to Different Site Conditions and Forest Age: A Case of Pinus Tabuliformis Plantations in the Temperate Mountainous Area of China

Background: Ecological stoichiometry is an important index that reflects the element cycle and ecosystem stability. In this study, two sites (sunny and shady slopes) and five forest ages (young forest, middle-aged forest, near-mature forest, mature forest, and over-mature forest) in a Pinus tabuliformis plantation were chosen to illustrate the effects of forest age and site on the biomass and stoichiometric characteristics of leaves and soils in the temperate mountainous area of China. Results: For all forest ages, the biomass, leaf total carbon, leaf total nitrogen, leaf total phosphorus of the leaves of P. tabuliformis on sunny slopes were all higher than those on shady slopes, while the nitrogen and phosphorus contents of the leaves showed the opposite of this. The biomass of leaves increased on sunny slopes, and increased first and then decreased in shady slopes with increasing forest age. The contents of soil total carbon (STC) and soil total nitrogen (STN) decreased with increasing soil depth, while the soil total phosphorus (STP) and soil available phosphorus (SAP) contents displayed the opposite. In addition to SAP, the average content of STC, STN, and STP in shady slopes was higher than that in sunny slopes, and the ratio was the opposite. Except for STC:STN on shady slopes, the other ratios showed a downward trend with an increase in soil depth. Excluding the topsoil, the change trend of STC:STP and STN:STP in shady slopes and sunny slopes was consistent with forest age. Conclusions: The results showed that forest age and site conditions had significant effects on leaf biomass. The biomass of the leaves is mainly limited by nitrogen. In management, it is recommended to plant on sunny slopes, especially in the young stage of P. tabuliformis plantation. In addition, it is suggested to apply a reasonable amount of nitrogen fertilizer to increase leaf biomass.

Disentangling the effects of past logging and ongoing cryptic anthropogenic disturbance on vegetation structure and composition in Himalayan Foothills, India

Most tropical forests have undergone commercial logging. Even where logging has ceased, subsistence harvest of forest resources often persists especially in South-East Asia. Understanding of impacts of frequent forest resources extraction in areas recovering from past selective logging would be essential for designing the appropriate management interventions.We studied the impacts of current chronic anthropogenic disturbances (hereafter CAD) and past selective logging on vegetation structure, diversity, and regeneration, and the invasion of a non-native shrub, Lantana camara, in three major forest types in the Himalayan foothills, India. We analyzed field data on intensity of CAD and vegetation variables, collected from 269 stratified random plots, using ordination and generalized linear (mixed) modeling approaches.Our results, based on 2758 adult trees of 54 species, showed that forest types differed in disturbance regimes depending on protection level and availability of fodder tree species. Intensity of CAD depended on proximity to settlements (for livestock related disturbances). Whereas selective logging, including firewood collection, was associated with land protection status. Selective logging reduced the extent of mature forest but facilitated regeneration, thereby promoting secondary forest features such as tree density and canopy cover. In contrast, the interaction between lopping and selective logging was negatively associated with regeneration. Past logging facilitated L. camara invasion in Dry and Hill forests but not in Moist forest. Finally, while selective logging marginally enhanced tree diversity, CAD reduced native shrub diversity.Our study demonstrates that selective logging followed by CAD arrest forest recovery, as evident from the suppression of mature forest elements, loss of shrub biomass, reduced regeneration rate, and facilitation of invasive species. To abate these impacts, alternative livelihood/subsistence options that sustain forests and local communities should be explored. Additionally, CAD management should be site-specific as local ecological contexts modify their impacts on forests.

Effects of anthropogenic degradation of an Andean temperate forest on the soil nutrients and on the diversity and function of the soil microbial community

&lt;p&gt;Soil microorganisms are an essential component of forest ecosystems being directly involved in the decomposition of organic matter and the mineralization of nutrients. Anthropogenic disturbances such as logging and livestock modify the structure and composition of forests and also the structure and diversity of soil microbial communities changing critical biogeochemical processes in the soil. In this research we evaluated the effect of anthropic disturbance on the soil in a degradation gradient of Andean temperate forest. This gradient comprises mature forest stands dominated by &lt;em&gt;Nothofagus dombeyii&lt;/em&gt;, secondary forests dominated by &lt;em&gt;Nothofagus alpina&lt;/em&gt; with medium degradation, a highly degraded forests dominated by &lt;em&gt;Nothofagus obliqua&lt;/em&gt; and a highly degraded grassland. We evaluate the reservoir of the main soil nutrients (TC, TN, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;, NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;) and the structure, diversity and functions of the soil microbial community (bacteria and fungi) via NGS-Illumina sequencing and metagenomic an&amp;#225;lisis with DADA2 pipeline in R-project. The results show a higher amount of TC, TN, NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; and C:N ratio in the most degraded condition (degraded grassland). There are no significant differences in the amount of TC, TN and NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt; along the forest degradation gradient. This reflects a C:N:P stoichiometry that tends to decrease as forest degradation increases. The soil bacteria community was mainly dominated by Phyla &lt;em&gt;Proteobacteria &lt;/em&gt;(45.35%), &lt;em&gt;Acidobacteria &lt;/em&gt;(20.73%), &lt;em&gt;Actinobacteria &lt;/em&gt;(12.59%) and &lt;em&gt;Bacteroidetes &lt;/em&gt;(7.32%). At genus level there are significant differences, &lt;em&gt;Bradyrhizobium &lt;/em&gt;has a higher relative abundance in the condition of mature forest which tends to decrease along the gradient of degradation forest. The soil fungi community was dominated by the Phyla &lt;em&gt;Ascomycota &lt;/em&gt;(42.11%), &lt;em&gt;Mortierellomycota &lt;/em&gt;(28.74%), &lt;em&gt;Basidiomycota &lt;/em&gt;(24.61%) and &lt;em&gt;Mucoromycota &lt;/em&gt;(2.06%). At genus level the condition of degraded grassland has significantly lower relative abundance of the genera &lt;em&gt;Mortierella &lt;/em&gt;and &lt;em&gt;Cortinarius&lt;/em&gt;. The degraded grassland soil microbial community is significantly less diverse in terms of bacteria (D' = 0.47&amp;#177;0.04) however it is significantly more diverse in terms of fungi (H' = 5.11&amp;#177;0.33).&lt;/p&gt;

Multi-taxon conservation in northern forest hot-spots: the role of forest characteristics and spatial scales

Context Biodiversity is highly affected by industrial forestry, which leads to the loss and fragmentation of natural habitats. To date, most conservation studies have evaluated associations among a single species group, forest type, or spatial scale. Objective The objective was to evaluate the richness of multiple species groups across various forest types and characteristics at multiple scales. Methods We used the occurrence data for 277 species of conservation interest from 455 stands of high conservation value, including four species groups and four forest types. Results Local, landscape, and regional forest characteristics influenced biodiversity in a non-uniform pattern among species groups and forest types. For example, an increased local spruce basal area in spruce forests was associated with higher vascular plant and bryophyte richness values, whereas macrofungi and lichen richness were positively correlated with deadwood availability, but negatively correlated with the spruce volume in the landscape. Furthermore, landscapes with twice as much mature forest as the average, had more than 50% higher richness values for vascular plants, macrofungi, and lichens. Conclusion Among sessile species groups in northern forests, a uniform conservation strategy across forest types and scales is suboptimal. A multi-faceted strategy that acknowledges differences among species groups and forest types with tailored measures to promote richness is likely to be more successful. Nevertheless, the single most common measure associated with high richness across the species groups and forest types was mature forest in the landscape, which suggests that increasing old forests in the landscape is a beneficial conservation strategy.

Stien i endring? Om det godes paradoks

The trail is the most important helping measure in friluftsliv (i.e. outdoor recreation or OR), mainly since walking in the neighborhood or local forest is the most frequent friluftsliv activity. Historically, trails were linear structures through the landscape to help people move from A to B for various purposes, and generally a trail was the result of systematic trampling along a preferred durable route. In OR, the activity and the experiences along the trail are often regarded as more important than moving from A to B. Preference studies in Norway have shown that a narrow, simple, dirt trail through an open, mature forest is the most attractive type of trail. Developed, graveled and broader trails are visually less attractive, likewise for wooden boardwalks. Today, new trails and restored trails seem to be systematically developed, broadened and hardened with gravel, wooden boardwalks or a stone surface. And there are many good reasons for this, like limiting erosion and ground impact, stimulating OR volume and thereby public health, helping disabled persons to access nature, building attractions for tourists, stimulating new activities (like biking), maintaining OR access in built-up areas, etc. A new “trail normality” is on the way, and I see (potential) losses: The friluftsliv culture and human–nature relation are changing, and a “graveled nature” is likely to be less attractive for children. Constant trail maintenance is needed, which takes the attention away from high quality friluftsliv landscape and replaces it with friluftsliv infrastructure. A heavy responsibility rests on the responsible OR management authorities in balancing various OR and trail measures.