Provision Of Ecosystem Functions Research Articles

Effect of light intensity on negative air ion under phytotron control.

Negative air ion (NAI) is an important index for measuring air quality and has been widely recognized to be influenced by photosynthesis processes. However, vegetation type and light intensity are also known to impact NAI, contributing to significant uncertainties in the relationship between light and NAI. In this paper, we selected Pinus bungeana, Platycladus orientalis and Buxus sinica as research subjects and obtained their NAI, light intensity, and meteorological data through synchronous observation under the relatively stable condition of the phytotron. We analyzed the change characteristics of NAI and the difference of NAI production ability in needle and broadleaf vegetation under different light intensities. Finally, we determined the relationship and underlying mechanism governing light intensity and NAI using diverse tree species. The results showed that the influence of light on NAI was significant. In the environment without vegetation, the influence of different light intensities on NAI was not significant, and the mean NAI concentration was 310 ions·cm-3. Conversely, in the presence of vegetation, NAI showed a "single-peak" trend with increasing light intensity. The NAI concentration of the three tree species was significantly higher than under different light intensities when vegetation was not present. The NAI promoting ability of P. bungeana was the highest (675 ions·cm-3), followed by P. orientalis (478 ions·cm-3) and B. sinica (430 ions·cm-3), which increased by 117.5%, 53.9% and 38.6% compared to the environment without vegetation. The NAI growth rate was significantly different between needle and broadleaf vegetation based on the specific tridimensional green biomass. Additionally, the NAI growth rates of P. bungeana and P. orientalis were 647 and 295 ions·cm-3·m-3, respectively, which were 3.06 and 1.39 times that of B. sinica (211 ions·cm-3·m-3). The piecewise equation fitting effect of NAI and light intensity was better for different tree species, the determination coefficients (R2) of P. bungeana, P. orientalis and B. sinica were 0.926, 0.916 and 0.880, and the root mean square errors (RMSE) were 7.157, 6.008 and 5.389 ion·cm-3, respectively. Altogether, our study provides a theoretical basis as well as technical support for the construction of healthy vegetation stands, the selection of preferred tree species, and the optimization of vegetation models, and promotes air quality and the provision of ecosystem functions and services.

HARNESSING ECOLOGICAL PRINCIPLES AND PHYSIOLOGIC MECHANISMS IN DIVERSIFYING AGRICULTURAL SYSTEMS FOR SUSTAINABILITY: EXPERIENCE FROM STUDIES DEPLOYING NATURE-BASED SOLUTIONS IN SCOTLAND

<List> <ListItem><ItemContent> ● Diversification enhances nature-based contributions to cropping system functions. </ItemContent></ListItem> <ListItem><ItemContent> ● Soil management to improve production and ecosystem function has variable outcomes. </ItemContent></ListItem> <ListItem><ItemContent> ● Management of the production-system to use legacy nutrients will reduce inputs. </ItemContent></ListItem> <ListItem><ItemContent> ● Intercrops, companion crops and cover crops improve ecological sustainability. </ItemContent></ListItem> <ListItem><ItemContent> ● Sustainable interventions within value chains are essential to future-proof agriculture. </ItemContent></ListItem></List> To achieve the triple challenge of food security, reversing biodiversity declines plus mitigating and adapting to climate change, there is a drive to embed ecological principles into agricultural, value-chain practices and decision-making. By diversifying cropping systems at several scales there is potential to decrease reliance on inputs, provide resilience to abiotic and biotic stress, enhance plant, microbe and animal biodiversity, and mitigate against climate change. In this review we highlight the research performed in Scotland over the past 5 years into the impact of the use of ecological principles in agriculture on sustainability, resilience and provision of ecosystem functions. We demonstrate that diversification of the system can enhance ecosystem functions. Soil and plant management interventions, including nature-based solutions, can also enhance soil quality and utilization of legacy nutrients. Additionally, this is facilitated by greater reliance on soil biological processes and trophic interactions. We highlight the example of intercropping with legumes to deliver sustainability through ecological principles and use legumes as an exemplar of the innovation. We conclude that there are many effective interventions that can be made to deliver resilient, sustainable, and diverse agroecosystems for crop and food production, and these may be applicable in any agroecosystem.

Pollinator interaction flexibility across scales affects patch colonization and occupancy.

Global change alters ecological communities and may disrupt ecological interactions and the provision of ecosystem functions. As ecological communities respond to global change, species may either go locally extinct or form novel interactions. To date, few studies have assessed how flexible species are in their interaction patterns, mainly due to the scarcity of data spanning long time series. Using a ten-year species-level dataset on the assembly of mutualistic networks from the Central Valley in California, we test whether interaction flexibility affects pollinators' colonization and persistence and their resulting habitat occupancy in a highly modified landscape. We propose three metrics of interaction flexibility associated with different scales of organization within ecological communities and explore which species' traits affect them. Our results provide empirical evidence linking species' ability to colonize habitat patches across a landscape to the role they play in networks. Phenological breadth and body size had contrasting effects on interaction flexibility. We demonstrate the relationship between mutualistic networks and species' ability to colonize and persist in the landscape, suggesting interaction flexibility as a potential mechanism for communities to maintain ecosystem function despite changes in community composition.

Estimating biodiversity changes in the Camargue wetlands: An expert knowledge approach.

Mediterranean wetlands are critical strongholds for biodiversity and the provision of ecosystem functions and services; yet, they are being severely degraded by a number of socio-economic drivers and pressures, including climate change. Moreover, we still lack comprehensive understanding of the extent to which biodiversity loss in Mediterranean wetlands will accelerate change in ecosystem processes. Here, we evaluate how changes in biodiversity can alter the ecosystem of the Camargue (southern France). We collected data on species presence/absence, trends and abundance over a 40-year period by combining observations from the scholarly literature with insights derived from expert knowledge. In total, we gathered more than 1500 estimates of presence/absence, over 1400 estimates of species abundance, and about 1400 estimates of species trends for eight taxonomic groups, i.e. amphibians, reptiles, breeding birds, fish, mammals, dragonflies (odonates), orthopterans and vascular plants. Furthermore, we used information on recently arrived species and invasive species to identify compositional changes across multiple taxa. Complementing targeted literature searches with expert knowledge allowed filling important gaps regarding the status and trends of biodiversity in the Camargue. Species trend data revealed sharp population declines in amphibians, odonates and orthopterans, while birds and plants experienced an average increase in abundance between the 1970s and the 2010s. The general increasing trends of novel and invasive species is suggested as an explanation for the changing abundance of birds and plants. While the observed declines in certain taxa reflect the relative failure of the protection measures established in the Camargue, the increasing exposure to novel and invasive species reveal major changes in the community structure of the different taxonomic groups. This study is the first attempt to assess changes in biodiversity in the Camargue using an expert knowledge approach, and can help manage the uncertainties and complexities associated with rapid social-ecological change in other Mediterranean wetlands.

Assessing the effects of shrubs on ecosystem functions in arid sand dune ecosystems

Shrub species play an important role in providing ecosystem functions and these functions may vary based on dominant shrubs and their facilitation roles in the arid ecosystems. This study was done to assess the potential of three shrubs (Tamarix macatensis, Calligonum polygonoides, and Haloxylon ammodendron) for providing three functions i.e. soil fertility, soil stability, and habitat provision in sand dune ecosystems of Iran. Two ecological indicators were selected to measure each function (soil organic matter content and litter mass for soil fertility; mound height and clay content for soil stability; understory plants and macrofauna diversity for habitat provision). As well, some shrub traits were measured for each shrub to assess their relationships with ecological indicators. Results showed that shrubs can significantly change ecological indicators (p < 0.05), except H. ammodendron which had no significant effect on habitat provision (p < 0.05). There were some relationships between shrub traits and provision of ecosystem functions. Stem density and litter production were the most important functional traits affecting regulating and habitat functions. Also, there was a significant positive relationship between soil fertility, soil stability and habitat provision (p < 0.05). It can be recommended that planting spherical shrubs with high potential for litter production will enhance functions and can sustainably maintain sand dunes in arid ecosystems.

Integrating trait-based empirical and modeling research to improve ecological restoration.

A global ecological restoration agenda has led to ambitious programs in environmental policy to mitigate declines in biodiversity and ecosystem services. Current restoration programs can incompletely return desired ecosystem service levels, while resilience of restored ecosystems to future threats is unknown. It is therefore essential to advance understanding and better utilize knowledge from ecological literature in restoration approaches. We identified an incomplete linkage between global change ecology, ecosystem function research, and restoration ecology. This gap impedes a full understanding of the interactive effects of changing environmental factors on the long‐term provision of ecosystem functions and a quantification of trade‐offs and synergies among multiple services. Approaches that account for the effects of multiple changing factors on the composition of plant traits and their direct and indirect impact on the provision of ecosystem functions and services can close this gap. However, studies on this multilayered relationship are currently missing. We therefore propose an integrated restoration agenda complementing trait‐based empirical studies with simulation modeling. We introduce an ongoing case study to demonstrate how this framework could allow systematic assessment of the impacts of interacting environmental factors on long‐term service provisioning. Our proposed agenda will benefit restoration programs by suggesting plant species compositions with specific traits that maximize the supply of multiple ecosystem services in the long term. Once the suggested compositions have been implemented in actual restoration projects, these assemblages should be monitored to assess whether they are resilient as well as to improve model parameterization. Additionally, the integration of empirical and simulation modeling research can improve global outcomes by raising the awareness of which restoration goals can be achieved, due to the quantification of trade‐offs and synergies among ecosystem services under a wide range of environmental conditions.

Geometrid moth assemblages reflect high conservation value of naturally regenerated secondary forests in temperate China

The widespread destruction of mature forests in China has led to massive ecological degradation, counteracted in recent decades by substantial efforts to promote forest plantations and protect secondary forest ecosystems. The value of the resulting forests for biodiversity conservation is widely unknown, particularly in relation to highly diverse invertebrate taxa that fulfil important ecosystem services. We aimed to address this knowledge gap, establishing the conservation value of secondary forests on Dongling Mountain, North China based on the diversity of geometrid moths – a species-rich family of nocturnal pollinators that also influences plant assemblages through caterpillar herbivory. Results showed that secondary forests harboured geometrid moth assemblages similar in species richness and phylogenetic diversity, but with a species composition distinctly different to assemblages in one of China’s last remaining mature temperate forests in the Changbaishan Nature Reserve. Species overlap between these sites was about 30%, and species did not form separate phylogenetic clusters according to site. Species assemblages at Dongling Mountain were strongly differentiated according to forest type; a pattern not found at Changbaishan. Our results indicate that protected naturally regenerated secondary forests in northern China provide suitable habitats for species-rich and genetically diverse geometrid moth assemblages, highlighting the potential importance of these forests for conservation and ecosystem function provision across the wider landscape.

Quantifying the effect of trend, fluctuation, and extreme event of climate change on ecosystem productivity.

Climate change comprises three fractions of trend, fluctuation, and extreme event. Assessing the effect of climate change on terrestrial ecosystem requires an understanding of the action mechanism of these fractions, respectively. This study examined 11years of remotely sensed-derived net primary productivity (NPP) to identify the impacts of the trend and fluctuation of climate change as well as extremely low temperatures caused by a freezing disaster on ecosystem productivity in Hunan province, China. The partial least squares regression model was used to evaluate the contributions of temperature, precipitation, and photosynthetically active radiation (PAR) to NPP variation. A climatic signal decomposition and contribution assessment model was proposed to decompose climate factors into trend and fluctuation components. Then, we quantitatively evaluated the contributions of each component of climatic factors to NPP variation. The results indicated that the total contribution of the temperature, precipitation, and PAR to NPP variation from 2001 to 2011 in Hunan province is 85%, and individual contributions of the temperature, precipitation, and PAR to NPP variation are 44% (including 34% trend contribution and 10% fluctuation contribution), 5% (including 4% trend contribution and 1% fluctuation contribution), and 36% (including 30% trend contribution and 6% fluctuation contribution), respectively. The contributions of temperature fluctuation-driven NPP were higher in the north and lower in the south, and the contributions of precipitation trend-driven NPP and PAR fluctuation-driven NPP are higher in the west and lower in the east. As an instance of occasionally triggered disturbance in 2008, extremely low temperatures and a freezing disaster produced an abrupt decrease of NPP in forest and grass ecosystems. These results prove that the climatic trend change brought about great impacts on ecosystem productivity and that climatic fluctuations and extreme events can also alter the ecosystem succession process, even resulting in an alternative trajectory. All of these findings could improve our understanding of the impacts of climate change on the provision of ecosystem functions and services and can also provide a basis for policy makers to apply adaptive measures to overcome the unfavorable influence of climate change.