The respiration of a plant is carried out all the time, but if you want a plant to photosynthesize, it is generally possible to reach 2000 lux light intensity.

Generally speaking, if you take the sunlight you see every day as a reference, the illumination of the sun at noon on a sunny day is more than 100000 lux, the sunlight illumination in the morning and evening on a sunny day is about 20000-40000 lux, the illumination of a cloudy and cloudy day is 5000-30000 lux, and the illumination of the interior near the window but without direct sunlight is 2000-8000 lux.

In this case, most plants will try to compete for sunlight in nature. The better the sun, the better the plants will grow. However, in some jungles, those tall trees have robbed most of the sunlight with their tall bodies and wide canopies.

In this case, the plants themselves will come up with their own tricks and multiply and flourish. One of these evolutions is yin-loving. These attractive plants, in nature, can grow in the shade beneath the canopy of those tall giant trees.

The light intensity is low, but because there are fewer competitors, it can survive and thrive.

Therefore, in the shade of the place, those shade-loving plants, can live more comfortably. Even indoors where there is no daylight, there is a household lighting that allows plants to photosynthesize. Moreover, the indoor air is relatively turbid. The raw material for photosynthesis is provided with more carbon dioxide. Therefore, many shade-loving plants can also survive, but the growth condition is not very good.

Therefore, many cultivators who are willing to cultivate flowers will supplement the plants raised indoors. Each square meter of plants will be controlled by LED lights and timers to automatically feed light. The time given to the light is about six to ten hours a day. In this way, those plants that are kept indoors can grow.

Otherwise, these plants would have starved to death by their own respiration.

For example, the most popular succulents on the market today have a minimum indoor growth requirement of about 3000 lux of light. If the light intensity is lower than this, it doesn't mean that the succulent won't grow any longer. Rather, it will not carry out high-quality, efficient growth.

Even the usual colors of succulents will probably no longer be there. This growth, in the circle of succulents, is called longevity.

In this vast underground world, the accumulation of fireflies is enough to form a point of extremely high brightness at a certain point, for example, a certain cluster, or a few clusters of glowing mushrooms. This brightness is at least about the same as the LED bulbs commonly used for lighting in the home.

And those mosses, and even dwarf ferns, grow next to or even in the middle of these glowing mushrooms, one of the brightest dots. In this way, these mosses and ferns can start photosynthesis. Grow up slowly. In the process of growth, the carbon dioxide produced in this empty underground space for various reasons is turned into oxygen.

Therefore, when Yun Lei and Rao Ya arrived at this place, they would not feel depressed. Instead, you will feel the fresh air.

Generally speaking, the relationship between mushrooms, which are fungi, and plants is similar to symbiosis or associated - plants can provide nutrients, oxygen, and shade for edible fungi, and edible fungi can provide them with carbon dioxide, decompose plant residues, and other biological residues, so that they can become nutrients that plants can absorb. In some cases, the two can also symbiotize to form mycorrhizae.

According to Yun Lei's estimates, after countless years of evolution in this vast underground space, the critical point for photosynthesis of these green mosses and verdant low ferns will be much lower than that of plants in the outside world.

Moreover, it forms an extremely strong attachment relationship with these luminescent fungi. These plants are able to grow because of these glowing mushrooms.

Although energy is lost in the process of conversion. However, with this river, which often brings many outside life and energy from the outside world, this unique ecosystem that relies on external matter and energy is established.

According to Yun Lei's estimate, the appearance of these unique creatures in this underground space should have been a long time ago. Because if the time is too short, those plants that have adapted to the external light conditions, and even those fungi that cannot emit light, will only have a dead end when entering such an underground space.

It is only after a relatively long period of evolution that mosses and low ferns, which are suitable for growing in the semi-shady areas of the primeval jungle, will gradually evolve to be able to barely adapt to this dark environment with only fluorescence.

Generally speaking, the evolution and final formation of a species takes at least tens of millions of years. In other words, at least tens of millions of years ago, it should still be connected to the outside world. Subsequently, natural selection is isolated from reproduction, and it comes into play.

A group of mosses and ferns adapted to grow here have evolved.

In other words, at least tens of millions of years, until 100 million years ago, this place was still connected to the outside world. The Tibetan Plateau in China, because of the northward drift of the Sinian plate, began to rise in the plateau tectonic process, which was precisely at that time.

Perhaps, those scientists are not unreasonable to explore the reasons for the formation of huge underground space on the Tibetan Plateau in China.

After Yun Lei and Rao Ya went ashore, they identified the high and low slope of the ground under their feet in this underground space. Then he walked towards the lower place. By now, the notes taken by the Prussian expedition members are no longer useful. Yun Lei and Rao Ya, and the Prussian scientific expedition team back then, took completely two paths.

And the environment of these two roads is not at all similar to the details of the experience.

However, this is normal, after all, in this vast underground space, if there is only one road and no fork in the road, it is really too abnormal.

The underground space that Yun Lei and Rao Ya saw in front of them probably didn't even find the Prussians back then. Or maybe only this place full of strange creatures is the right path to Nashambala.

Although Yun Lei and Rao Ya have lost their way now, it is not too difficult to find the location of the underground magma. The underground magma flowing from the eruption must be the lowest place in this underground space.

Or, close to the lowest part of the subterranean space.

Yun Lei and Rao Ya only need to judge the lowest place in this space. And this is also easy to judge, find a ball, in the case of stationary, which side the ball rolls to, which side of the terrain is low. Just follow along, anyway.