Problem statement
I am building a world where the flora and fauna is based on that of Gondwana, the lost supercontinent that consisted of South America, Africa, Madagascar, India, Australia and Antarctica. One of the key biomes of this continent, linking all the other regions together, is a vast savanna stretching across the continent in the tropical and sub-tropical regions.
我正在建立一个植物群和动物群基于冈瓦纳的世界，冈瓦纳是由南美洲，非洲，马达加斯加，印度，澳大利亚和南极洲组成的失落的超大陆。该大陆的一个关键生物群落，将所有其他地区连接在一起，是一片广阔的热带草原，横跨整个大陆的热带和亚热带地区。
The wildlife of this continent is based on those creatures that evolved after the fall of the dinosaurs, but only on the southern continents. Many of the most common land mammals that we know of today evolved in the north (Laurasia, at the time) so the only mammals on the continent are prototheres (egg-layers), marsupials (opposum and kangaroo and more), xenarths (sloths and anteaters), and afrotheres (elephants, elephant shrews, hyrax, and aardvark).
这个大陆的野生动物是基于恐龙沦陷后进化的那些生物，但仅限于南部大陆。我们今天所知的许多最常见的陆地哺乳动物在北方进化（Laurasia，当时），因此该大陆上唯一的哺乳动物是prototheres（卵层），有袋动物（对峙和袋鼠等），xenarth（树懒）和食蚁兽）和afrotheres（大象，大象sh ,,海狸鼠和土豚）。
If you look at those animals, you will see preponderance of insect eaters, such as aardvark, armadillo, anteaters, echidna and more. So, this sort of mammal ecosystem is best justified by a dominance of termites as the primary herbivores.
如果你看看这些动物，你会看到优势的昆虫食用者，如土豚，犰狳，食蚁兽，针鼹等。因此，这种哺乳动物生态系统最好通过白蚁作为主要食草动物的优势来证明其合理性。
Question
What changes, if any, do I need to make to a world to justify termites being the primary herbivores on a semi-open savanna?
如果有的话，我需要做些什么改变来证明白蚁是半开放式稀树草原上的主要食草动物？
Considerations
-
The competition from termites must be such that grazing herbivores never evolve. In turn, mammalian carnivores that specialize in grazing herbivores (wolves, lions, etc) never evolve. There are a couple of shrub browsers (kangaroo) and a few tree-destroyers (elephant and giant sloth), but nothing like wildebeest, horses, or buffalo.
来自白蚁的竞争必须使放牧食草动物从未进化。反过来，专门放牧食草动物（狼，狮子等）的哺乳动物食肉动物从未进化。有几个灌木浏览器（袋鼠）和一些树驱逐舰（大象和巨型树懒），但没有像牛羚，马或水牛。
-
Large predators in this world are either birds or reptiles (giant monitors or land crocodiles).
这个世界上的大型食肉动物是鸟类或爬行动物（巨型监视器或陆地鳄鱼）。
-
The savanna biome is immense, covering nearly half the continent, an area larger than Africa. There is a mix of grassland, open forest, and closed thorn thicket. The termites must be dominant in all parts of the savanna.
热带稀树草原生物群系非常庞大，覆盖了大陆的一半，面积比非洲大。草原，开阔的森林和封闭的刺丛林混合在一起。白蚁必须在热带稀树草原的所有部分占主导地位。
-
If climate affects competition between termites and herbivores, it can be adjusted to favor the termites, so long as the mix of tree and shrub types is possible.
如果气候影响白蚁和食草动物之间的竞争，只要可以混合树木和灌木类型，就可以调整白蚁和白蚁。
3 个解决方案
#1
3
Make grass a bad source of nutrients. It's not the competition from termites that causes grazing herbivores to never evolve, it's their lack of a suited food source.
使草成为营养的重要来源。不是白蚁的竞争导致放牧食草动物从未进化，而是缺乏适合的食物来源。
Grazing animals rely on grass as a fast regrowing source of nutrients. In turn, they drop their manure on the plains, fertilizing the soil for the next generation of grass. If this cycle is broken (or doesn't exist to begin with), there's much less fresh grass than one would expect and bush fires may regularily destroy what's left.
放牧动物依靠草作为快速再生的营养来源。反过来，他们将粪肥放在平原上，为下一代草坪施肥。如果这个周期被打破（或者开始时不存在），那么新鲜的草比预期的要少得多，丛林火灾可能会定期破坏剩下的东西。
Grass blades have sharp edges, occasionally causing little cuts if you draw them through your fingers. The sharpness is caused by little crystals lined up on the very edge of the leaf / blade. In addition, the flat of a grass blade is covered with little hairs that act like barbs. You can draw a blade through your fungers in one direction, but not in the other.
草叶有锋利的边缘，如果你用手指画草，偶尔会造成很小的伤害。锋利度是由叶片/叶片边缘排列的小晶体引起的。此外，草叶的扁平部分覆盖着像倒钩一样的小毛发。你可以在一个方向上通过你的游乐者画一把刀片，而不是在另一个方向上。
If you eat grass, you have to cope with these defence mechanisms. These could have caused herbivores to specialize on "less defended" food like bushes or roots, where thorns can be evaded.
如果你吃草，你必须应对这些防御机制。这些可能导致食草动物专注于“防御性较差”的食物，如灌木丛或根部，可以避开荆棘。
Another consideration is the water source of plants. Grass cannot reach its roots as deep as bushes or trees, so it depends on regular rain. On a continent like Pangea without major moutains or diversity in biomes, how often does it rain? There might be one rather short rain season a year (if at all) like in the african savanna. Gigantic herds of grazing herbivores have to literally cross the african continent twice a year to find sufficient fresh grass to survive. Pangea might be too big for such migrations, killing grazing species on the continent alltogether.
另一个考虑因素是植物的水源。草不能像灌木丛或树木一样深入其根部，因此它取决于常规的降雨。在像Pangea这样没有大型山脉或生物群落多样性的大陆上，它经常下雨吗？一年中可能会有一个相当短的雨季（如果有的话），就像非洲大草原一样。巨大的放牧食草动物群必须每年两次穿越非洲大陆才能找到足够的鲜草来生存。 Pangea对于这种迁徙来说可能太大了，完全杀死了非洲大陆的放牧物种。
#2
2
Perhaps a disease would be a good way of doing this. If you only had a couple of grazing mammal species to begin with, they could infect each other, or through the water.
也许一种疾病是一种很好的方法。如果您开始只有几种放牧的哺乳动物物种，它们可以相互感染或通过水感染。
Some bison equivalent to black plague or ebola, that would drive the population down to below the threshold for genetic variety.
一些相当于黑瘟疫或埃博拉病毒的野牛会使人口降至遗传多样性的阈值以下。
I think that species appear very gradually, and disappear suddenly. Species appear from similar previous species. In this case, nothing similar is left, and the termites have taken over the ecological niche of eating plant and being food for predators. It's similar to the way Madagascar has lemurs in the niche that monkeys fill elsewhere. Monkeys never reappeared there.
我认为物种看起来非常缓慢，并且突然消失。物种出现在类似的先前物种中。在这种情况下，没有留下类似的东西，白蚁已经占据了食用植物的生态位，成为捕食者的食物。它类似于马达加斯加在猴子填充其他地方的利基中的狐猴方式。猴子再也没有出现在那里。
#3
1
There are only trees.
只有树木。
资源
Grazers need grass. Browsers need browse. In this world it is too dry for that. There are only trees - big ones that can reach the water deep underground. Wood is the only readily available vegetable matter. Termites are the only animals that can subsist on wood.
Grazers需要草。浏览器需要浏览。在这个世界上它太干了。只有树木 - 可以到达地下深处的大树。木材是唯一容易获得的植物性物质。白蚁是唯一可以在木材上生存的动物。
#1
3
Make grass a bad source of nutrients. It's not the competition from termites that causes grazing herbivores to never evolve, it's their lack of a suited food source.
使草成为营养的重要来源。不是白蚁的竞争导致放牧食草动物从未进化，而是缺乏适合的食物来源。
Grazing animals rely on grass as a fast regrowing source of nutrients. In turn, they drop their manure on the plains, fertilizing the soil for the next generation of grass. If this cycle is broken (or doesn't exist to begin with), there's much less fresh grass than one would expect and bush fires may regularily destroy what's left.
放牧动物依靠草作为快速再生的营养来源。反过来，他们将粪肥放在平原上，为下一代草坪施肥。如果这个周期被打破（或者开始时不存在），那么新鲜的草比预期的要少得多，丛林火灾可能会定期破坏剩下的东西。
Grass blades have sharp edges, occasionally causing little cuts if you draw them through your fingers. The sharpness is caused by little crystals lined up on the very edge of the leaf / blade. In addition, the flat of a grass blade is covered with little hairs that act like barbs. You can draw a blade through your fungers in one direction, but not in the other.
草叶有锋利的边缘，如果你用手指画草，偶尔会造成很小的伤害。锋利度是由叶片/叶片边缘排列的小晶体引起的。此外，草叶的扁平部分覆盖着像倒钩一样的小毛发。你可以在一个方向上通过你的游乐者画一把刀片，而不是在另一个方向上。
If you eat grass, you have to cope with these defence mechanisms. These could have caused herbivores to specialize on "less defended" food like bushes or roots, where thorns can be evaded.
如果你吃草，你必须应对这些防御机制。这些可能导致食草动物专注于“防御性较差”的食物，如灌木丛或根部，可以避开荆棘。
Another consideration is the water source of plants. Grass cannot reach its roots as deep as bushes or trees, so it depends on regular rain. On a continent like Pangea without major moutains or diversity in biomes, how often does it rain? There might be one rather short rain season a year (if at all) like in the african savanna. Gigantic herds of grazing herbivores have to literally cross the african continent twice a year to find sufficient fresh grass to survive. Pangea might be too big for such migrations, killing grazing species on the continent alltogether.
另一个考虑因素是植物的水源。草不能像灌木丛或树木一样深入其根部，因此它取决于常规的降雨。在像Pangea这样没有大型山脉或生物群落多样性的大陆上，它经常下雨吗？一年中可能会有一个相当短的雨季（如果有的话），就像非洲大草原一样。巨大的放牧食草动物群必须每年两次穿越非洲大陆才能找到足够的鲜草来生存。 Pangea对于这种迁徙来说可能太大了，完全杀死了非洲大陆的放牧物种。
#2
2
Perhaps a disease would be a good way of doing this. If you only had a couple of grazing mammal species to begin with, they could infect each other, or through the water.
也许一种疾病是一种很好的方法。如果您开始只有几种放牧的哺乳动物物种，它们可以相互感染或通过水感染。
Some bison equivalent to black plague or ebola, that would drive the population down to below the threshold for genetic variety.
一些相当于黑瘟疫或埃博拉病毒的野牛会使人口降至遗传多样性的阈值以下。
I think that species appear very gradually, and disappear suddenly. Species appear from similar previous species. In this case, nothing similar is left, and the termites have taken over the ecological niche of eating plant and being food for predators. It's similar to the way Madagascar has lemurs in the niche that monkeys fill elsewhere. Monkeys never reappeared there.
我认为物种看起来非常缓慢，并且突然消失。物种出现在类似的先前物种中。在这种情况下，没有留下类似的东西，白蚁已经占据了食用植物的生态位，成为捕食者的食物。它类似于马达加斯加在猴子填充其他地方的利基中的狐猴方式。猴子再也没有出现在那里。
#3
1
There are only trees.
只有树木。
资源
Grazers need grass. Browsers need browse. In this world it is too dry for that. There are only trees - big ones that can reach the water deep underground. Wood is the only readily available vegetable matter. Termites are the only animals that can subsist on wood.
Grazers需要草。浏览器需要浏览。在这个世界上它太干了。只有树木 - 可以到达地下深处的大树。木材是唯一容易获得的植物性物质。白蚁是唯一可以在木材上生存的动物。