Large-scale forest inventories of the United States and China reveal positive effects of biodiversity on productivity

Background： With the loss of species worldwide due to anthropogenic factors, especially in forested ecosystems, it has become more urgent than ever to understand the biodiversity-ecosystem functioning relationship （BEFR）. BEFR research in forested ecosystems is very limited and thus studies that incorporate greater geographic coverage and structural complexity are needed. Methods： We compiled ground-measured data from approx, one half million forest inventory sample plots across the contiguous United States, Alaska, and northeastern China to map tree species richness, forest stocking, and productivity at a continental scale. Based on these data, we investigated the relationship between forest productivity and tree species diversity, using a multiple regression analysis and a non-parametric approach to account for spatial autocorrelation. Results： In general, forests in the eastern United States consisted of more tree species than any other regions in the country. The highest forest stocking values over the entire study area were concentrated in the western United States and Central Appalachia. Overall, 96.4 % of sample plots （477,281） showed a significant positive effect of species richness on site productivity, and only 3.6 % （17,349） had an insignificant or negative effect. Conclusions： The large number of ground-measured plots, as well as the magnitude of geographic scale, rendered overwhelming evidence in support of a positive BEFR. This empirical evidence provides insights to forest management and biological conservation across different types of forested ecosystems. Forest timber productivity may be impaired by the loss of species in forests, and biological conservation, due to its potential benefits on maintaining species richness and productivity, can have profound impacts on the functioning and services of forested ecosystems.

Applying Humboldt’s holistic perspective in China’s sustainability

Alexander von Humboldt,was a great German geobotanist,educator and naturalist who greatly influenced sci-ence and humanities for more than two hundred years.In addition to scientific contributions(such as the un-derstanding of vegetation distribution,the concepts of isotherm and pressure contours,and the initial concept of continental drift theory),he firmly believed in the concept of the interconnection of everything and the method-ological approach of a holistic perspective to development,which has significance in achieving the UN Sustainable Development Goals,because they include both synergy and trade-offs among these goals.China has undergone tremendous changes since its reform and opening up in 1978 and now faces severe challenges in sustainable de-velopment.The scientific methods applied by Chinese scientists in sustainability fulfil the Humboldtian holistic perspective of nature.Here I provide four successful cases and their significant implications for addressing the increasingly severe water shortage,biological conservation,and conflicts between human well-being and land.The four examples discussed in this article are enlightened to establish a strong,just,and influential government and require empirical research to implement sustainable development plans.I believe that it’s vital to encourage and supervise public participation for a successful program;for example,the participants should not be restricted to project executors,i.e.,farmers or workers,but also students and scientists.Eradicating poverty must be priori-tized,and well-being is the ultimate goal for sustainable development.This review article provides an extremely valuable reference for other developing or even developed countries to address sustainability challenges.

Two-way predation between immature stages of the hoverfly Eupeodes corollae and the invasive fall armyworm(Spodoptera frugiperda J.E.Smith)

Since its 2018 invasion of eastern Asia,the fall armyworm Spodoptera frugiperda(Lepidoptera:Noctuidae)has become a key pest in local maize production.Though pesticides have been widely used to mitigate the initial S.frugiperda attack,biological control is receiving ample attention as a desirable,environmentally-sound alternative to chemical control.Hoverflies(Diptera:Syrphidae)are abundant natural enemies in Chinese maize fields and have been observed to consume S.frugiperda larvae.In this study,we use laboratory assays to study the two-way interaction between immature stages of S.frugiperda and the endemic syrphid Eupeodes corollae.To mimic natural conditions,assays were performed in the presence of fresh maize leaves.Those 2 nd or 3 rd instar larvae of E.corollae preyed on 1 st and 2 nd instar S.frugiperda larvae with a Holling type III response,consuming a respective theoretical maximum of 43.48 and 83.33 larvae over a 24-h period.Conversely,once S.frugiperda larvae reached 3 rd instar,they exhibited aggressive behavior and equally preyed on syrphid larvae with a Holling type III response.Those 5 th and 6 th instar larvae of S.frugiperda consumed a respective 16.39-19.23,6.02-19.61 and 6.76-8.26 of 1 st,2 nd and 3 rd instar E.corollae larvae per day.Though our results await field-level validation,S.frugiperda agonistic(i.e.,defensive)and consumptive behavior towards resident natural enemies such as E.corollae possibly degrades biotic resistance and raises its invasion potential.Our findings shine new light on the interaction between lepidopteran herbivores and their natural enemies,and can help advance the development of conservation biological control and other integrated pest management(IPM)strategies against S.frugiperda in China and abroad.

Quantitative method for identifying networks of minimum priority sites for protection of rare and endangered plant species in Guangdong,China

The approaches to enlarge the protected areas are deeply embedded in the conservation planning.In practice,however,even in some sites of top conservation priority,there exist problems of inefficient conservation for lack of funding,to say nothing of assisting all species under threat from the viewpoint of conservationists.Identifying priority sites for conservation and establishing networks of minimum priority sites(NOMPS)are helpful for promoting the transition from number and size oriented,to quality and effectiveness oriented practices of biological conservation,and for realizing the target of biodiversity conservation with the most benefits for the least costs.Based on heuristic algorithm and integer linear programming(ILP),we propose a refined method of heuristic integer linear programming(HILP)for quantitative identification of the NOMPS to protect rare and endangered plant species(REPS)in Guangdong Province,China.The results indicate that there are 19 priority sites which are essential for protecting all of the 107 REPS distributed in 83 sites in Guangdong.These should be the paramount targets of financing and management.Compared with the ILP,which uses minimum number of sites as the only constraint,HILP takes into consideration of the effect of species richness,and is thus more suitable for conservation practices though with a little more number of priority sites selected.It is suggested that ILP and HILP are both effective quantitative methods for identifying NOMPS and can yield important information for decision making,especially when economic factors are constraints for biological conservation.

Towards more-than-human heritage:arboreal habitats as a challenge for heritage preservation

Trees belong to humanity’s heritage,but they are more than that.Their loss,through catastrophic fires or under business-as-usual,is devastating to many forms of life.Moved by this fact,we begin with an assertion that heritage can have an active role in the design of future places.Written from within the field of architecture,this article focuses on structures that house life.Habitat features of trees and artificial replacement habitats for arboreal wildlife serve as concrete examples.Designs of such habitats need to reflect behaviours,traditions and cultures of birds,bats,and other animals.Our narrative highlights the nonhuman aspect of heritage,seeking to understand how nonhuman stakeholders can act as users and consumers of heritage and not only as its constituents.Our working definition states that more-than-human heritage encompasses tangible and intangible outcomes of historical processes that are of value to human as well as nonhuman stakeholders.From this basis,the article asks how the established notions of heritage can extend to include nonhuman concerns,artefacts,behaviours and cultures.As a possible answer to this question,the hypothesis tested here is that digital information can(1)contribute to the preservation of more-than-human heritage;and(2)illuminate its characteristics for future study and use.This article assesses the potential of three imaging technologies and considers the resulting data within the conceptual framework of more-than-human heritage,illuminating some of its concrete aspects and challenges.

Mechanisms for flowering plants to benefit arthropod natural enemies of insect pests： Prospects for enhanced use in agriculture

Reduction of noncrop habitats, intensive use of pesticides and high levels of disturbance associated with intensive crop production simplify the farming landscape and bring about a sharp decline of biodiversity. This, in turn, weakens the biological control ecosystem service provided by arthropod natural enemies. Strategic use of flowering plants to enhance plant biodiversity in a well-targeted manner can provide natural enemies with food sources and shelter to improve biological control and reduce dependence on chemical pesticides. This article reviews the nutritional value of various types of plant-derived food for natural enemies, possible adverse effects on pest management, and the practical application of flowering plants in orchards, vegetables and field crops, agricultural systems where most research has taken place. Prospects for more effective use of flowering plants to maximize biological control of insect pests in agroecosystem are good but depend up on selection of optimal plant species based on information on the ecological mechanisms by which natural enemies are selectively favored over pest species.

Knowing your enemies： Integrating molecular and ecological methods to assess the impact of arthropod predators on crop pests

The importance of natural enemies as the foundation of integrated pest management （IPM） is widely accepted, but few studies conduct the manipulative field experiments necessary to directly quantify their impact on pest populations in this context. This is particularly true for predators. Studying arthropod predator-prey interactions is inherently difficult： prey items are often completely consumed, individual predator-prey interactions are ephemeral （rendering their detection difficult） and the typically fluid or soft-bodied meals cannot be easily identified visually within predator guts. Serological techniques have long been used in arthropod predator gut-contents analysis, and current enzyme linked immunosorbent assays （ELISA） are highly specific and sensitive. Recently, poly- merase chain reaction （PCR） methods for gut-contents analysis have developed rapidly and they now dominate the diagnostic methods used for gut-contents analysis in field-based research. This work has identified trophic linkages within food webs, determined predator diet breadth and preference, demonstrated the importance of cannibalism and intraguild predation within and between certain taxa, and confirmed the benefits （predator persis- tence） and potential disadvantages （reduced feeding on pest species） of the availability of alternative nonpest prey. Despite considerable efforts to calibrate gut-contents assays, these methods remain qualitative. Available techniques for predator gut-contents analysis can provide rapid, accurate, cost-effective identification of predation events. As such, they perfectly compliment the ecological methods developed to directly assess predator im- pacts on prey populations but which are imperfect at identifying the key predators. These diagnostic methods for gut-contents analysis are underexploited in agricultural research and they are almost never applied in unison with the critical field experiments to measure predator impact. This paper stresses the need for a combined approach and suggests a framework that would make this possible, so that appropriate natural enemies can be targeted in conservation biological control.

Assessing the short-term impact of an insecticide （Deltamethrin） on predator and herbivore abundance in soybean Glycine max using a replicated small-plot field experiment

A greater understanding of the relative impact of insecticide use on non-target species is critical for the incorporation of natural enemies into integrated pest management strategies. Here we use a small-plot field trial to examine the relative impact of an insec- ticide on herbivores and predators found in soybean （Glycine max L.）, and to highlight the issues associated with calculating impact factors from these studies. The pyrethroid insecticide （Deltamethrin） caused a significant reduction in invertebrate abundance in the treated plots, and populations did not recover to pre-treatment levels even 20 days af- ter spraying. To assess the relative impact of the spray on arthropods we first examined the mean difference in abundance in each plot before and after spraying. All herbivores decreased in abundance in the sprayed plots but increased in the control plots after spray- ing. Most predators （excluding hemipterans） showed a decrease in the control plots but a proportionally greater decrease in the sprayed plots. Next we examined the corrected per- centage population reduction calculated using Abbott＇s formula. All predators （including Araneae） experienced a greater reduction （mean 87% 4- 3.54 SE） than herbivores （mean 56% -4- 4.37 SE） and Araneae alone （mean 71% 4- 8.12 SE）. The range in values across the plots varied and made categorising overall impact subjective for some taxa. Despite the constraints associated with small-plot trials, by using a combination of impact factors and examining community-level response across time, we did get some indication of the likely impact of this insecticide if used in a commercial situation.