Ecological Constraints Research Articles

Interaction time with conspecifics induces food preference or aversion in the wild Algerian mouse

The social transmission of a novel food preference can avoid unnecessary costs arising from tasting nonedible foods. This type of social learning has been demonstrated in laboratory rats and mice. However, among wild animals, there may be several constraints that make it less effective. Using wild Algerian mice (Mus spretus) tested in the laboratory, we demonstrate that a preference for a novel food can be transmitted between Observer and Demonstrator individuals and that it is maintained for at least 30 days. However, only half of the Observers acquired a preference for the same food as the Demonstrators, and only when the duration of oronasal investigation was above a certain threshold (≥122 s); below this threshold (<122 s), Observers acquired a preference for the alternative food offered, which was maintained for a shorter time. Sex, size, and identity of individuals did not influence the transmission of social information. The results show that different interaction times will result in animals copying or avoiding the food choices of others. This suggests that the transmission of social information among wild animals is complex and probably influenced by many factors (e.g., dominance, familiarity, and health condition), ultimately conditioning the type of interaction between individuals and its outcome. Testing wild animals and the ecological and social constraints they face is, therefore, an important step in our understanding of how effectively social information is transmitted in nature.

Spatio-temporal evolution and future simulation of urban agglomeration expansion in the Guangdong–Hongkong–Macau Greater Bay Area

Urban agglomerations are growth poles that promote regional economic development; however, rapid expansion exerts an increasingly negative influence on regional ecosystem security, restricting sustainable urban development. Therefore, predicting the impact of future expansion on regional ecological security can guide regionally coordinated development. In this study, we used land-use data to determine the spatiotemporal evolution of urbanization and land use in the Guangdong–Hong Kong–Macao Greater Bay Area (GBA) urban agglomeration from 1990 to 2020 and employed the artificial neural network–cellular automata (ANN–CA)–Markov model to simulate future expansion under three different scenarios for 2025 and 2035. From 1990 to 2020, the overall development level of the GBA urban agglomeration was relatively high, with the area of construction land following a pattern of first increasing rapidly and then gradually transitioning to a slower rate of growth. Land use was consistently dominated by forest land, which accounted for more than 50% of the total land area, followed by arable land (30.56%) and construction land (7.92%). The most intense expansion in the GBA occurred in the main urban areas of Guangzhou, Shenzhen, Foshan, Dongguan, and other cities. The expansion sources were mainly farmland, water, and other ecological land types. The spatial structure and characteristics of simulated future regional land-use changes in 2025 and 2035 differed significantly under the three different scenarios. Under the natural development scenario, urban expansion was unconstrained, and rapid growth occurred over a large area of ecological land. Conversely, the addition of ecological constraints effectively controlled the occupation of forest land and cultivated land. Under the economic development scenario, urban expansion incorporated more unused and cultivated land. The results of this study provide a reference for policy decision-making in regional planning, urban planning, and regional ecological protection under multiple future scenarios.

A complex subsistence regime revealed for Cucuteni–Trypillia sites in Chalcolithic eastern Europe based on new and old macrobotanical data

We present a comprehensive data-based characterization of the subsistence economy of Chalcolithic Cucuteni–Trypillia societies (CTS) on the Moldovian and Suceava plateaus and the Podolian and the Dnieper uplands. This study is based on a quantitative evaluation of archaeobotanical samples from 34 settlement sites, with a focus on Trypillia mega-sites and on stable isotopic analysis of ancient crop residues. The isotopic analysis allows us to identify specific cultivation strategies, which show a close relationship with animal husbandry for manure. We describe the economy of the Trypillia mega-sites as having been based on an elaborate agricultural system, in which the inhabitants knew how to grow crops that could withstand the ecological constraints of growth, especially along the forest steppe ecotone. We also argue that the agglomeration of greater population densities at these mega-sites contributed to landscape change from woodland and forest to open grassland and steppe. Following on from this, we suggest that cultivation practices of the CTS were important in the establishment of the present-day cultural steppe in this region.

Effects of Forest Fragmentation on Connectivity and Genetic Diversity in an Endemic and an Invasive Rodent in Northwestern Madagascar.

Habitat loss and fragmentation are of concern to conservation biologists worldwide. However, not all organisms are affected equally by these processes; thus, it is important to study the effects of living in fragmented habitats on species that differ in lifestyle and habitat requirements. In this study, we examined the dispersal and connectivity patterns of rodents, one endemic (Eliurus myoxinus) and one invasive (Rattus rattus), in two landscapes containing forest fragments and adjacent continuous forest patches in northwestern Madagascar. We generated genetic (RADseq) data for 66 E. myoxinus and 81 R. rattus individuals to evaluate differences in genetic diversity as well as inbreeding and connectivity in two landscapes. We found higher levels of inbreeding and lower levels of genetic diversity in E. myoxinus compared with R. rattus. We observed related dyads both within and between habitat patches and positive spatial autocorrelation at lower distance classes for both species, with a stronger pattern of spatial autocorrelation in R. rattus. Across each site, we identified contrasting migration rates for each species, but these did not correspond to habitat-matrix dichotomies. The relatively low genetic diversity in the endemic E. myoxinus suggests ecological constraints that require further investigation.

Natural Climate Solutions must embrace multiple perspectives to ensure synergy with sustainable development

To limit global warming to well below 2°C, immediate emissions reductions must be coupled with active removal of greenhouse gases from the atmosphere. “Natural Climate Solutions” (NCS) achieve atmospheric CO2 reduction through the conservation, restoration, or altered management of natural ecosystems, with enormous potential to deliver “win-win-win” outcomes for climate, nature and society. Yet the supply of high-quality NCS projects does not meet market demand, and projects already underway often fail to deliver their promised benefits, due to a complex set of interacting ecological, social, and financial constraints. How can these cross-sectoral challenges be surmounted? Here we draw from expert elicitation surveys and workshops with professionals across the ecological, sociological, and economic sciences, evaluating differing perspectives on NCS, and suggesting how these might be integrated to address urgent environmental challenges. We demonstrate that funders” perceptions of operational, political, and regulatory risk strongly shape the kinds of NCS projects that are implemented, and the locations where they occur. Because of this, greenhouse gas removal through NCS may fall far short of technical potential. Moreover, socioecological co-benefits of NCS are unlikely to be realized unless the local communities engaged with these projects are granted ownership over implementation and outcomes.

Comparing landscape partitioning approaches to protect wildlife habitat in managed forests

Industrial forestry activities can increase landscape fragmentation, impacting wildlife populations, particularly Canada’s woodland caribou, Rangifer tarandus caribou. To protect caribou in areas with forestry activities, the province of Ontario, Canada, implemented a Dynamic Caribou Harvest Schedule (DCHS). The DCHS spatially aggregates harvest disturbance into regions and distributes them across the landscape to maintain forest patch size–age distributions consistent with a natural variation range. However, the DCHS may negatively impact the cost of timber supply. We compared the DCHS with an alternative zoning approach that assigned the harvest deferral and operational management zones within a large forest area. We compared these approaches using an optimization model that combined harvest scheduling, access road construction, and caribou protection sub-problems. We formulated the protection of caribou habitat and road construction as network flow problems, while the harvesting problem incorporated the ecological constraints prescribed by the forest management plan. We compared the DCHS and zoning approaches in the Wabadowgang Noopming Forest of Ontario, a boreal area within the caribou distribution zone. For the same volume of sustainable harvest, the zoning approach protected less total area but more habitat and old-growth stands over the long term, and yielded lower timber costs by 1.2–2.2 $·m−3 than the DCHS.

Integrated perspective of eco-innovation, green branding, and sustainable product: a case of an emerging economy

Climate complexities and environmental problems not only brought changes in organizational practices but also changed the consumer purchasing pattern. Consumers nowadays have become more cautious regarding the consumption pattern of firms due to ecological footprints. This increased awareness influences their buying decisions pattern which leads to the increased demand of sustainable products. Eco-innovation, in this regard, appears to be an effective tool that helps firms to incorporate ecological constraints into business practices in order to develop green branding which ultimately leads to green loyalty. Drawing on literature from existing literature, the study developed a complex framework and established the plausible relationship among outlined constructs. By utilizing PLS methodology, measurement and structural models were assessed. Results echo that eco-innovation and green branding lead to sustainable product. Moreover, evidence also indicate that eco-innovation, and sustainability positively influence green loyalty. Based on the evidence, study proposed some implications which may be helpful for policy makers to maintain the sustainability of a firm.

Towards sustainable marine spatial planning of aquaculture

An efficient and adaptive strategy within the EU Marine Spatial Planning Directive has to manage the existing and increasing conflicts between human uses and habitat conservation in coastal-marine areas. Among the different human activities developed along the coasts, aquaculture occupies a primary role. In this context, the aims of this research have been: (1) to propose a conceptual model suitable for aquaculture marine spatial planning; (2) to collect and integrate indicators useful for the characterization of the study area in terms of socio-ecological-economic sensitivities and pressures; and (3) to identify and map the most suitable areas for the development of new fish and shellfish farms. The study area is the Apulia Region (Southern Italy) with a coastline of about 1,000 km, in the Adriatic and Ionian Seas, and characterized by several economic activities within a high value natural context. The evaluation of area’s suitability for fish and shellfish farms have been carried out through the ecological characterization of the coastal areas, the identification of the socio-economic, ecological, cultural, and legal-military constraints and the estimate of the “Suitability Index” that, through a Weighted Linear Combination, integrates environmental variables and allows to classify areas as “Highly Suitable”, “Suitable” or “Unsuitable”. The “highly suitable areas” for new fish and shellfish farms are mainly located in northernmost of the Southern Adriatic Sea along the Gargano coast and in the Gulf of Manfredonia, whilst concerning the Northern Ionian Sea they are at a mean distance of 5 Km from the shoreline. The suitability maps have shown that existing fish farms are in line with their suitable areas but, surprisingly, this has seemed not to be true for shellfish farms. This can be explained by the fact that these aquaculture activities have traditionally been present in some areas (e.g., Taranto Seas), currently strongly impacted by human activities. This research has highlighted that despite aquaculture is generally conceived as an environmental impacting activity, it could be also impacted by other environmental and/or anthropic stressors (i.e., industrial ports, sewage discharges). Considering all these elements, the present research addresses decision-makers, providing information and tools necessary to plan in a more aware way, and also stakeholders interested in investing in the aquaculture sector, who could benefit from the proposed suitability maps for fish and shellfish farms for a sustainable development of this sector.

Molecular and genetic perspectives of cold tolerance in wheat.

Environmental variation is the most crucial problem as it is causing food insecurity and negatively impacts food availability, utilization, assessment, and stability. Wheat is the largest and extensively cultivated staple food crop for fulfilling global food requirements. Abiotic stresses including salinity, heavy metal toxicity, drought, extreme temperatures, and oxidative stresses being the primary cause of productivity loss are a serious threat to agronomy. Cold stress is a foremost ecological constraint that is extremely influencing plant development, and yield. It is extremely hampering the propagative development of plant life. The structure and function of plant cells depend on the cell's immune system. The stresses due to cold, affect fluid in the plasma membrane and change it into crystals or a solid gel phase. Plants being sessile in nature have evolved progressive systems that permit them to acclimatize the cold stress at the physiological as well as molecular levels. The phenomenon of acclimatisation of plants to cold stress has been investigated for the last 10 years. Studying cold tolerance is critical for extending the adaptability zones of perennial grasses. In the present review, we have elaborated the current improvement of cold tolerance in plants from molecular and physiological viewpoints, such as hormones, the role of the posttranscriptional gene, micro RNAs, ICE-CBF-COR signaling route in cold acclimatization and how they are stimulating the expression of underlying genes encoding osmoregulatory elements and strategies to improve cold tolerance in wheat.

Optimization of China's freight transportation structure based on adaptive genetic algorithm under the background of carbon peak.

Transportation is the key carbon emission source after energy supply and industrial production. Under the vision of carbon peak and carbon neutralization, the pressure of reducing carbon emissions in transportation will be greater in the future. This paper constructs a model that takes transportation carbon emission as the main target and freight transportation utility value as the auxiliary target. The constructed model satisfies the constraints of freight turnover in the whole society, freight economic and social benefits, and the ecological constraints of the freight system. With MATLAB, the freight turnover of roadways, railways, and waterways (excluding ocean transportation) in 2030 is solved by using the adaptive genetic algorithm. The results indicate that (I) compared with the current freight structure of China, the roadway freight sharing rate in 2030 will decrease by 8.07%, and the railway freight sharing rate and the waterway freight sharing rate (excluding ocean transportation) will increase by 0.93% and 7.13%, respectively. (II) After optimization, the energy consumption and carbon emission are reduced by 42,471,500 tons (10.3%) and 91,379,400 tons (10.2%) of standard coal, respectively. (III) The adaptive genetic algorithm outperforms the traditional genetic algorithm in terms of convergence speed and accuracy. (IV) As the weight coefficient of carbon emission increases, the utility value of freight transportation consistently decreases, and the sensitivity increases. Meanwhile, as the carbon emission weight coefficient increases, carbon emission keeps decreasing, and the sensitivity decreases.

The Low-Carbon Economy as an Institutional Project: Challenges and ObjectivesMargarita V. Kurbatova

The article considers the process of creating new laws in the sphere of ecological regulation in connection with the climate change to be the means of shaping new institutional structures that can potentially transform the behavior of economic actors and the directions of resource flows. The problem statement and goal setting for the institutional design of the climate-environment agenda are scrutinized in the article. Scientific and political-economic foundations for choosing the direction of the global community's response to the threats of climate change and the corresponding institutional changes are highlighted in this research. The mechanisms of sustainable development priorities transformation towards the reduction of greenhouse gas emissions through the transition to renewable energy sources are demonstrated in the paper. The concept of the low-carbon economy associated with the carbon-neutral constraints on economic activity is described in the paper in details. The author offers the project of institutional transformation that implies the creation of new institutions for a global response to climate change threats. The measures for ensuring the mild adaptation of economic actors to the new type of ecological constraints are also elaborated. According to the authors, one of the most significant challenges of climate change lies in the creation and simultaneous existence of overlapping institutional projects at the global and national levels. Given the inevitability of climate change, the measures ensuring the adaptation of the economy and society to the consequences of ecological changes should be prioritized. It is recommended to intensify the formation of the institutional project in line with the national interest of creating a competitive advantage for the Russian economy.

Towards sustainable management of agricultural resources: A framework to assess the relationship between water, soil, economic factors, and grain production

As the requirements for environmental protection and high-efficiency economies increase, grain production (GP) across the globe faces more stringent ecological constraints and economic pressure. Understanding the relationships between natural resources and economic and agricultural factors in grain-producing regions is paramount for ensuring global food security. This paper proposes a methodological framework to explore the relationships between water and soil resources (WSRs), economic input factors (EIFs), and GP. We employed the northeast region of China as a case study to advance our understanding of the factors driving the development of grain-producing capacity. We first constructed and calculated the region's water and soil comprehensive index (WSCI) to describe water-soil properties. We then used hotspot analysis to explore the spatial agglomeration characteristics of WSRs, EIFs, and GP. Finally, we used threshold regression analysis to understand the effects of EIFs and GP with the WSCI as the threshold variable. With the improvement of the WSCI, the positive impact of fertilizer and irrigation on GP shows a U-shaped curve in elasticity coefficients. The positive effect of agricultural machinery on GP decreases significantly, and the impact of labor input on GP is insignificant. These results provide new insights into the relationship between WSRs, EIFs, and GP and a reference for improving GP efficiency globally. This work thus contributes to advancing our capabilities to enable food security while considering aspects of sustainable agriculture in important grain-producing regions across the globe.

Spring arrival of the common cuckoo at breeding grounds is strongly determined by environmental conditions in tropical Africa.

Failure to adapt migration timing to changes in environmental conditions along migration routes and at breeding locations can result in mismatches across trophic levels, as occurs between the brood parasitic common cuckoo Cuculus canorus and its hosts. Using satellite tracking data from 87 male cuckoos across 11 years, we evaluate why the cuckoo has not advanced its arrival to the UK. Across years, breeding ground arrival was primarily determined by timing of departure from stopover in West Africa before northward crossing of the Sahara. Together with high population synchrony and low apparent endogenous control of this event, this suggests that a seasonal ecological constraint operating here limits overall variation in breeding grounds arrival, although this event was itself influenced by carry-over from timing of arrival into tropical Africa. Between-year variation within individuals was, in contrast, mostly determined by northward migration through Europe, probably due to weather conditions. We find evidence of increased mortality risk for (a) early birds following migration periods positively impacting breeding grounds arrival, and (b) late birds, possibly suffering energy limitation, after departure from the breeding grounds. These results help identify areas where demands of responding to global change can potentially be alleviated by improving stopover quality.

The effect of water footprint and economic growth on environmental degradation: applications of optimization modeling

Abstract In this study, the effect of economic growth, energy consumption, biological capacity, and trade liberalization on the economic water footprint of consumption as an indicator of environmental degradation was investigated. An optimization framework was developed to find the maximum values of economic water footprint based on environmental, ecological, energy, and technical constraints. The results of the study showed that the simulated relationship can be used together to estimate long-term relationships between variables, there is a positive and significant relationship between ecological footprint and biological capacity and a negative and significant relationship between trade globalization and economic water footprint. The middle form of the ecological footprint N also increases energy consumption leading to an increase in the economic water footprint. Moreover, the results showed that there is a relationship with economic growth, and this indicates that the increase in economic growth in this region will lead to further destruction of the environment.

Genetic control underlying the flowering-drought tolerance trade-off in the Antarctic plant Colobanthus quitensis.

Plants inhabiting environments with stressful conditions often exhibit a low number of flowers, which can be attributed to the energetic cost associated with reproduction. One of the most stressful environments for plants is the Antarctic continent, characterized by limited soil water availability and low temperatures. Induction of dehydrins like those from the COR gene family and auxin transcriptional response repressor genes (IAAs), which are involved in floral repression, has been described in response to water stress. Here, we investigated the relationship between the water deficit-induced stress response and the number of flowers in Colobanthus quitensis plants collected from populations along a latitudinal gradient. The expression levels of COR47 and IAA12 genes in response to water deficit were found to be associated with the number of flowers. The relationship was observed both in the field and growth chambers. Watering the plants in the growth chambers alleviated the stress and stimualted flowering, thereby eliminating the trade-off observed in the field. Our study provides a mechanistic understanding of the ecological constraints on plant reproduction along a water availability gradient. However, further experiments are needed to elucidate the primary role of water availability in regulating resource allocation to reproduction in plants inhibiting extreme environments.

Development of a decision framework for river health and water yield ecosystem service in watershed

Maintaining river health in a changing environment is an important way to improve the service value of the river basin ecosystem. An ecological flow threshold process with multiple ecological constraints was proposed using the Range of Variability Approach method and the Improved Intra-annual Spreading method. When combined with the multi-source dataset and the InVEST model, a 'ecology-function pattern-driven and decision' service framework was proposed. The study found that the important ecological constraints of the ecological flow in the Xiangjiang River basin changed after the hydrological change (1991–2019). High pulse occurrence times were delayed by 3 d, while low pulse occurrence times and durations were advanced by 8 d and delayed by 10 d, respectively. Temperature, precipitation, and evapotranspiration are all important factors influencing the dynamic characteristics of the basin's water yield services. Human activities and climate change have contributed nearly 19% more to the temporal and spatial differentiation characteristics of water yield in the basin than in the natural period. Additionally, it was discovered that excessive rainfall can inhibit the impact of other variables on water yield within the basin. Furthermore, the pivotal levels of significant meteorological factors that affect the water yield value of the basin were elucidated. This research leads to a better knowledge of watershed hydrological health in changing environments and a scientific basis for local water resource management decisions and optimal utilization of ecosystem service values.

Simulating Urban Agglomeration Expansion in Henan Province, China: An Analysis of Driving Mechanisms Using the FLUS Model with Considerations for Urban Interactions and Ecological Constraints

Urban expansion is influenced by complex and variable social, economic, natural, and policy-related factors. Given their nonlinear interactions, accurately modeling these urban expansion processes poses a challenge. While most studies treat the city as an independent entity, prioritizing internal urban factors, urban land expansion is influenced by intercity interactions and the ecological environment. This study proposes a new approach that couples the gravitational field model, ecological constraints, and the Future Land Use Simulation (FLUS) model, comprehensively considering the impact of intercity interaction and the ecological environment. The experiment in Henan Province in China assessed the effects of factors such as basic spatial variables (Slope and distance to the city center), urban gravitational field, and ecological constraints on urban expansion through the optimal parameters-based geographical detector (OPGD) model. The feasibility of the method was confirmed by this case study, which shows that it improves the simulation accuracy of the urban agglomeration scale, particularly for central cities. We identified the urban gravitational field and ecological constraints as two important factors affecting the expansion of urban agglomerations. Areas with stronger urban spatial fields are more likely to attract neighboring resources and promote urban expansion, whereas ecological factors constrain the expansion behavior of cities under the condition of ecological and environmental resource protection needs, and both of them work together to influence the expansion behavior of urban clusters. Therefore, we posit that intercity interactions and ecological constraints are important considerations for the future spatial planning of urban agglomerations and for coordinating the harmonious development of urbanization and ecological conservation.

An Improved Future Land-Use Simulation Model with Dynamically Nested Ecological Spatial Constraints

A land-use simulation model oriented toward ecological constraints is effective for evaluating the ecological impact of urban spatial planning. However, few studies have incorporated dynamically nested ecological spatial constraints into the model or fully considered the urban development, agricultural production, and ecological function among the ecological spatial constraints. Therefore, this study developed an improved land-use simulation model with dynamically nested ecological spatial constraints (LSDNE). We fully considered the multilevel ecological spatial constraints from the perspectives of ecological (ecological protection red line, EPRL), production (capital farmland, CF), and living (urban development land-use suitability, UDLS). Five scenarios in terms of future land-use distribution in 2030 were set, namely, inertial development (S1), considering EPRL (S2), considering CF (S3), considering EPRL and CF (S4), and considering EPRL, CF, and UDLS (S5). This new approach was implemented in the rapidly developing provincial capital city of Changchun, China. The results show that, due to the occupation of arable land, Changchun had the largest increase in built-up land (2019.75 km2 to 3036.36 km2) from 2010 to 2020. Terrain elevation was the most significant factor in all kinds of land expansion. According to future land spatial distribution results in 2030, under S4, Changchun’s built-up land will be more compact compared with S1–S3 and S5, which showed more scattered built-up land. These predicted results show that Changchun’s spatial planning put forward high requirements for the efficient use of land and constraints in red-line areas. Due to a clear evaluation of the impact of ecological spatial constraints on future land expansion, the LSDNE model provides more accurate support for the efficient use of land resources and future territorial spatial planning.

Behavioral assays reveal mechanisms of supercolony formation in odorous house ants

The formation of expansive multi-nest and multi-queen supercolonies is perhaps the most important factor responsible for the ecological success of invasive ants. The odorous house ant, Tapinoma sessile, is a widespread ant native to North America. T. sessile is a challenging urban pest, but also serves as an interesting system to study ant social organization and invasion biology. This is due to its remarkable dichotomy in colony social and spatial structure between natural and urban environments. Natural colonies typically consist of a small number of workers, inhabit a single nest, and are monogyne whereas urban colonies show extreme polygyny and polydomy and form large supercolonies. The current study examined the extent to which T. sessile colonies from different habitats (natural vs. urban) and social structures (monogynous vs. polygynous) exhibit aggression toward alien conspecifics. Additionally, interactions between mutually aggressive colonies were examined in colony fusion experiments to assess the potential role of colony fusion as a mechanism leading to supercolony formation. Aggression assays demonstrated high levels of aggression in pairings involving workers from different urban colonies and workers from different natural colonies, but low aggression in pairings involving queens from different urban colonies. Colony merging tests demonstrated that urban T. sessile colonies are highly aggressive to each other, but capable of fusing under laboratory conditions when competing for limited nesting and food resources. Despite highly aggressive interactions and relatively high worker and queen mortality, all colony pairs merged in 3–5 days. Fusion occurred after most workers died and the survivors merged. This result suggests that the success of T. sessile in urban areas may be driven, at least in part, by successful colony mergers of unrelated colonies which may be determined by ecological constraints such as seasonal shortages in nest and/or food availability. In summary, two independent factors including the growth of a single colony and/or the merger of multiple colonies may be responsible for the evolution of supercolonies in invasive ants. Both processes may be happening simultaneously and may act synergistically to produce supercolonies.

The contribution of plant life and growth forms to global gradients of vascular plant diversity.

Plant life and growth forms (shortened to 'plant forms') represent key functional strategies of plants in relation to their environment and provide important insights into the ecological constraints acting on the distribution of biodiversity. Despite their functional importance, how the spectra of plant forms contribute to global gradients of plant diversity is unresolved. Using a novel dataset comprising > 295 000 species, we quantify the contribution of different plant forms to global gradients of vascular plant diversity. Furthermore, we establish how plant form distributions in different biogeographical regions are associated with contemporary and paleoclimate conditions, environmental heterogeneity and phylogeny. We find a major shift in representation of woody perennials in tropical latitudes to herb-dominated floras in temperate and boreal regions, following a sharp latitudinal gradient in plant form diversity from the tropics to the poles. We also find significant functional differences between regions, mirroring life and growth form responses to environmental conditions, which is mostly explained by contemporary climate (18-87%), and phylogeny (6-62%), with paleoclimate and heterogeneity playing a lesser role (< 23%). This research highlights variation in the importance of different plant forms to diversity gradients world-wide, shedding light on the ecological and evolutionary pressures constraining plant-trait distributions.