Karst regions are characterized by heterogeneous soil habitats, with shallow wide soil (SW) on hilly slopes and deep narrow soil (DN) in rocky trenches. To make full use of limited water and nutrients, plants have therefore developed a number of root extension strategies. This study investigated the effect of soil moisture on horizontal root extension in SW and vertical root extension in DN by assessing root growth responses, biomass allocation, and root distribution. A full two-way factorial blocked design of soil dimensions by water availability was followed. The perennial grass Lolium perenne L. was grown in SW and DN under high (W100%), moderate (W50%), and low (W30%) water availability, respectively. The main results were as follows: (1) The total biomass of L. perenne was not influenced either by soil habitat or by water application. Root length, root surface area, root biomass and root to shoot ratio all decreased with decreasing water application in SW, but not in DN soil. (2) With decreasing water application, the cumulative percentage of root length, root surface area and root biomass in 4 rings from the center out to 12 cm of SW soil showed a trend of W50% > W30% > W100% in SW, however, the cumulative percentage of root biomass in 4 layers from the surface to a depth of 36 cm was not significantly different between different water treatments in DN. (3) Under all three water treatments, specific root length showed an increase but root length density showed a decreasing trend from the center outward in SW soil or from the surface to bottom in DN soil. Overall, these results suggest that in SW habitat, soil moisture determines horizontal expansion of the roots in L. perenne , although the overall expansion ability was limited in severe drought. However, due to the relatively strong water retention ability, soil moisture changes were less obvious in DN, resulting in no significant vertical extension of the root system. The root response of L. perenne helps our understanding of how herbaceous plants can adjust their belowground morphology to support their growth in harsh karst soil environments.

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Natural light is an important factor of human survival and development, which determines human survival and development. Without natural light, human beings will not be able to survive and develop.Space activities are the main ways for people to live, work and learn. Space design will have a great impact on people's activities. Good space design can promote indoor activities.Under the background of rapid socio-economic development, people's economic income is increasing, living standard is increasing, and interior design is developing rapidly.In addition, with the development of land space, land space is also becoming narrower.On the other hand, the oceans have great potential for space resources.The space available to the oceans consists of three parts: the coast, the ocean and the seabed.It is therefore necessary to study the development of marine areas.The purpose of this paper is to fully understand the role of natural light in coastal space design, master the relationship between natural light and space design, and ensure the effective fusion of the two.This paper explores the relationship between natural light and indoor environment.Taking the application of natural light in spatial design as an example, the characteristics of natural light in spatial design are analyzed, and the concept of natural light design space is discussed. In addition, the advantages of natural light utilization in coastal areas were identified by comparing buildings in inland and coastal areas. Therefore, this research provides an opportunity for the design of spatial natural lighting to become an important design element and is of great significance.In the future, we will be able to study the application relationship between sustainable natural light and various art forms in marine space.

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Coastal space is an important part of urban environment, has strong spatial permeability, is an open space of cities, blending ecosystem and human-made construction. The study designs and explores how to create coastal public spaces based on the concept of interaction design. Integrate technology into the city image of life while ensuring an ecological and sustainable natural environment. It is divided into five parts. Chapter 1 begins with the background of the topic, explains the background and research goals of the topic study, introduces the research methods and scope of this study, and establishes a preliminary research plan. Chapter 2 provides a theoretical interpretation of the concept of interaction design and public spaces along the city coast. Briefly describe the concept, origin and development process of interaction design and coastal public spaces. Identify the domestic and international status of coastal public space interaction design and organize related references. It provides a theoretical basis for applying the concept of interaction design to the design of public environmental facilities in coastal spaces. And before studying each factor, the relevance of the study is presented. Chapter 3 presents the goals and principles of strengthening human-human interaction in public space design under the concept of interaction design, promoting people-public space interaction experiences, and harmonizing the environment and facilities. Through understanding the concept of interaction design and planning in coastal areas, this study uses SD methods to identify users' use needs and finally propose optimization plans and design principles to build a public space for interaction design in coastal spaces. It is hoped to provide a theoretical basis for designing public spaces using interaction in coastal areas in the future.